CA1258400A - Low calorie, low fat fruit-containing yogurt product and method for making same - Google Patents
Low calorie, low fat fruit-containing yogurt product and method for making sameInfo
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- CA1258400A CA1258400A CA000438805A CA438805A CA1258400A CA 1258400 A CA1258400 A CA 1258400A CA 000438805 A CA000438805 A CA 000438805A CA 438805 A CA438805 A CA 438805A CA 1258400 A CA1258400 A CA 1258400A
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Abstract
ABSTRACT
A low calorie, low fat fruit-containing custard-type yogurt product having a fat content less than about 0.2% by weight prepared by thoroughly admixing high temperature short time (HTST) pasteurized skim milk, having a fat content of less than 0.2% by weight, with specially heat-modified nonfat dry milk solids, suitable stabilizers, optional vitamin and mineral fortifiers, sweeteners, flavorants and/or colorants; heating the mixture to about 190° to 195°F (87.7 to 90.6°C) for about 20 to 60 minutes; adding optional heat labile vitamins, such as Vitamin C; homogenizing the mixture by conventional means at about 1000 to 2000 psig (70.03-140.06 kg/cm2); cooling the homogenized mixture to about 110°F (43.3°C); and inoculating the cooled mixture with a uniquely proportioned blend of standard yogurt cultures. If a Swiss style yogurt is to be produced, the inoculated mixture is cooled, pumped through a pressure valve to obtain a smooth texture, blended with low calorie fruit preserves, packaged in suitable con-tainers and refrigerated to stop fermentation. For a Western style yogurt, the inoculated mixture is added to containers containing low calorie fruit preserves and cooled to stop fermentation. The low calorie fruit preserves comprise 40 to 50% by weight fruit in an invert sugar syrup containing at least 36% by weight fructose.
A low calorie, low fat fruit-containing custard-type yogurt product having a fat content less than about 0.2% by weight prepared by thoroughly admixing high temperature short time (HTST) pasteurized skim milk, having a fat content of less than 0.2% by weight, with specially heat-modified nonfat dry milk solids, suitable stabilizers, optional vitamin and mineral fortifiers, sweeteners, flavorants and/or colorants; heating the mixture to about 190° to 195°F (87.7 to 90.6°C) for about 20 to 60 minutes; adding optional heat labile vitamins, such as Vitamin C; homogenizing the mixture by conventional means at about 1000 to 2000 psig (70.03-140.06 kg/cm2); cooling the homogenized mixture to about 110°F (43.3°C); and inoculating the cooled mixture with a uniquely proportioned blend of standard yogurt cultures. If a Swiss style yogurt is to be produced, the inoculated mixture is cooled, pumped through a pressure valve to obtain a smooth texture, blended with low calorie fruit preserves, packaged in suitable con-tainers and refrigerated to stop fermentation. For a Western style yogurt, the inoculated mixture is added to containers containing low calorie fruit preserves and cooled to stop fermentation. The low calorie fruit preserves comprise 40 to 50% by weight fruit in an invert sugar syrup containing at least 36% by weight fructose.
Description
- 1~5~34~)() DESCRIPTION
Low Calorie, Low Fat Fruit-Containing Yogurt Product and Method for Making Same TECIINICAL FIELD
-The present invention relates generally to a method for making a fruit-containing yogurt product having the appearance, texture and taste of conventional custard-type fruit-containing yogurt and the product thereof;
more specifically the invention relates to a method for making a fruit-containing yogurt product having a fat and calorie content significantly below that of conven-tional fruit-containing yogurt.
BACKGROUND ART
In recent years cultured milk products, referred to as yogurt, have enjoyed immense popularity. The bene-ficial effects on health due to the therapeutic proper-ties of the bacterial cultures contained in yogurt are well known. In addition, yogurt has become a popular food among dieters. To increase its appeal, the sharp, tangy taste charac-teristic of plain, unflavored yogurt, which heretofore made yogurt unacceptable to many people, has been masked in many yogurt products with fruit and sweeteners. This practice has resulted in a flavored yogurt product that is more palatable to a wider segment of the population. However, the use of these additives has been accompanied by an increase in product calorie content from about 90 calories per eight ounce (224 grams) serving of plain, unflavored yogurt to about 250 to 270 calories per eight ounce (224 grams~
serving of the sweetened, fruit-containing yogurt. Such a high ~., .
1~5~0 calorie content renders the fruited product generally unsuitable for inclusion in reducing diets since the fruit yogurt uses up the majority of the calories usually alloted to a single meal. As a result the 5 dieter has~difficulty choosing a sufficient variety or quantity of foods to form a balanced meal within the remaining calories allowed. Accordingly, a need has developed for a fruit-containing yogurt product which is low in calories, fat and carbohydrate content.
1~ Prior methods for producing sweetened or flavored yogurt have succeeded in obtaining a product with a relatively low butterfat content, for example, as low as the 0.5% butterfat content of ordinary skim milk, but none seem to have been able to produce a really low 15 fat, less than about 0.5%, yogurt product having the characteristic creamy custard-type yogurt consistency while at the same time overcoming the high calorie and high carbohydrate problems accompanying the use of fruited or flavored yogurt. One reason for this is 20 that yogurt previously made from really low fat milk products, less than about 0.5% butterfat, has been loose and watery and lacking in flavor rather than creamy and custard-like with consumer acceptable flavor, appearance and mouth feel. Efforts to overcome 25 this problem to obtain a palatable product have either required adding flavor influencing milk solids, which increases the yogurt calorie content, or increasing the milk fat content, which has a similar effect~
Exemplary of prior methods for producing flavored 30 yogurt is U.S. Patent No. 3,969,534 to Pavey et al which teaches the production of a fruited, flavored yogurt which has a relatively low, about 0.5%, butterfat content. However, the product produced by the Pavey method does not appear to be low in _3_ ~ 2 5 B ~o ~
carbohydrates or significantly lower in calories than conventional flavored yogurt. In U.S. Patent No.
3,025,165, Metzger discloses a process for producing yogurt which uses relatively low butterfat starting materials, such as skim milk, to which is added about 1.5% to 6.4~ of an unsaturated vegetable oil. As a result, a higher than desirable fat content for a reducing diet is obtained without significantly reducing the number of calories. Likewise, the fruited yogurt product produced by the process disclosed in U.S. Patent No. 3,269,842 to Mayer et al has a fat content of about 4% and appears to be a high calorie, high carbohydrate product. Donay et al in U.S. Patent No.3,128,190, discloses the use of a skim milk starting material.
However, the process for making Donay's fruit-containing yogurt requires fruit which is precooked with sucrose to prevent fermentation thereof by the yogurt cultures with resultant unpleasant flavors. As a result of this pro-cedure the Donay et al method neither produces really low fat yogurt nor reduces the high calorie and carbo-hydrate content of fruit-containing yogurt. In U.S.
Patent No. 4,110,476, Rhodes discloses a process for preparing liquid, rather than custard-type, yogurt products which utilize whey protein concentrate together with milk products as the starting material ingredients and contain higher sugar contents than are desirable for a fruit-containing yogurt product suitable for a reducing diet.
As disclosed in the prior art e.g., U.S. Patents 3,969,534, 4,096,287 and 4,110,476 (supra) conventional nonfat milk solids can be used in the manufacture of yogurt products.
In the manufacture of yogurt products, however, the use of conventional nonfat milk solids has not resulted in the preparation of satisfactory low calorie yogurt products having acceptable texture and mouth feel. It has been found that it is only when,conventional nonfat milk solids are used in conjunction with the uniquely proportioned blend of three lactic acid producing bac-terial cultures of the present ~5~340~
invention, as is more fulLy described hereinafter, that they con-tribute to -the production of low fat and low calorie yogur-t product having a consumer acceptable consistency, texture and mouth feel with a calorie content significantly below that of known custard-type yogurt products.
Disclosure of the Invention In one form of the present invention there is provided a fruit-containing yogurt product which resembles conventional yogurt in appearance, texture and taste, but which has a fat and calorie content signifi-cantly below that of known custard-type yogurt products.
In yet another form of the present inven-tion there is provided a nutritious, palatable, fruit-containing yogurt product which has the creamy mouth feel and the sweetr fruity, slightly tangy taste of conven-tional custard-type yogurt but which has a fat content below about 0.2~ by weight of the final product.
Another form of the present inven-tion provides a method for making a very low fat and low calorie fruit-containing, custard-type yogurt product.
In accordance with one embodiment of -the present invention there is provided a method for making a less than about 0.2% by weight fat and low calorie yogurt product containing fruit in an amount up to about 20% by weight of the yogurt product and 17 to 20~ by weight total solids, the method comprising -the steps of: (a) admixing pasteurized skim milk having a fat content of less than about 0.2% by weight, stabilizers and an amount of non-heat modified nonfat dry milk solids effective to improve te~ture and flavor, the nonfat dry milk solids having been subjected to no heat treating other than pasteurization heat treating prior to spray drying; ~b) heating the mix-ture to a temperature in the range from about 1900 to 1950F (87.7 to 90.60C) for a time 1~25~34~0 - 4a -sufficient to form a uniform, substantially homogeneous mixture and to effect pasteurization; (c) homogenizing the pas-teurized mixture at pressure in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2); (d) cooling the homogenized mixture to a temperature of about 90 to 1200F (32.2 to 48.90C); (e) inoculating the cooled homogenized mixture ! with a lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50%
Lactobacillus acidophilus, balance Lactobacillus bulgaricu_ and Streptococcus thermophilus in approximately equal proportions; (f) maintaining the inoculated mixture at a -temperature oE about 90 to 1200F (32.3 to 48.90C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in the inoculated mixture; (g) cooling the inoculated mixture; (h) forming the cooled inoculated mixture into a smooth textured product, (i) blending the smooth textured product with low calorie frui-t preserves; and (j) cooling the blend of fruit preserves and smooth textured product to a temperature sufficiently low to stop farmentation.
In accordance with another embodiment of the present invention there is provided a method for making a less than about 0.2% by weight fat and low calorie yogur-t product containing fruit in an amount up to about 20% by weigh-t of the yogurt product and 17 to 20% by weight total solids, the method comprising the steps of: (a) admixing pasteurized skim milk having a fat content of less than about 0.2% by weight, stabilizers and an amount of non-heat modified nonfat dry milk solids effective to improve texture and flavor, the nonfat dry milk solids having been subjected to no heat treating other than pasteurization hea-t treating prior to spray drying; (b) heating the mixture to a temperature in the range from about 190 to 1950F (87.7 to 90.60C) for a time sufficient to form a uniform, substantially homogeneous mix-ture and to effect pas-teurization; (c) homogenizing the pasteurized mixture - 4b -at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2); (d) cooling the homogenized mixture to a temper-ature of about 90 to 1200F (32.2 to 48.90C): (e) inoculating the cooled homogenized mixture with a laetie acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50% Laetobaeillus aeidophilus, balanee Laetobaeillus bulgarieus and Streptocoeeus thermophilus in approximately equal proportions; (f) adding the inoeulated mixture into individual yogurt eontainers eontaining low ealorie ruit preserves; (g) maintaining the fruit preserves and inoe-ulated mixture at a temperature of about 90 to 1200F (32.2 to ~8.90C) for a time suffieient to produee a pH in the ! range of about 3.8 to 4.8 to form an aceeptable taste and texture in inoeulated mixture, and (h) eooling the fruit preserves and inoculated mixture to a temperature sufficiently low to stop fermentation.
In accordance with a further embodiment of the present invention there is provided a low calorie, low fat and fruit-containing yogurt product, characterized in that the yogurt produet has fruit and yogurt to resemble eonventional fruited yogurt in appearanee, texture and taste, and by having a fat content less than about 0.2% by weight of the produet; a fruit eontent of up to about 20%
by weight of the produet; and a calorie content of about 150 calories per eight ounce serving.
In accordanee with a further embodiment of the present invention there is provided a method ~or making a less than about 0.2% by weight fat and low calorie yogurt produet, ineluding the steps of admixing low fa-t eontent pasteurized milk, stabilizers and non-heat modified nonfat dry milk solids, heating the mixture to a temperature in the range from about 190 to 1950F (87.7 to 90.60C), homogenizing the mixture at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/em2), cooling the homogenized mixture to a temperature of about 90 to ~25~3400 - 4c ~
120OF (32.2 to 48.9OC), inoculating the cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture, maintaining the inoculated mixture at a temperature of about 90 to 120OF (32.2 to 48.9OC) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in the inoculated mixture, the improvement comprising the lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50~ Lactobacillus !10 acidophilus, balance Lactobacillus bulgaricus and Streptococcus thermophilus in approximately equal proportions.
In accordance with still a further embodiment of the present invention there is provided a method for making a less than about 0.2~ by weight fat and low calorie yogurt product containing fruit in an amount up -to about 20~ by weight of the yogurt product and 17 to 20% by weight total solids, including the steps of admixing low fat content pasteurized milk, stabilizers and non-heat modified nonfat dry milk solids, heating the mixture to a temperature in the range from about 190 to 195OF (87.7 to 90.6OC), homogenizing the mixture at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2) cooling the homogenized mixture to a temperature of about 90 to 120OF (32.2 to 48.9OC), inoculating the cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture, maintaining the inocu-lated mixture at a temperature of about 90 to 120OF (32.2 to 48.9OC) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in the inoculated mixture and combining the inoculated mixture with low calorie fruit preserves either before or after the maintaining step, the improvement comprising the lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50~ Lactobacillus acidophilus, balance ~s~o~
- 4d -Lactobacillus bulgaricus and Streptococcus thermophilus in approximately equal proportions.
In accordance with one embodiment of the method of the presen-t invention a process for making a low fat, low calorie, fruit-containing yogurt product resembling conventional fruit-containing yogur-t in appearance, texture and taste which includes the steps of admixing pasteurized s~im milk having a fat content of less than about 0.2%, preferably less than about 0.1%, with suitable stabilizers and an amount of nonfat dry milk solids effective to improve texture and flavour; adding optional vitamin and mineral fortification, sweeteners, flavorants and/or colorants; heating the resulting mixture with constant agitation to about 190 to 195OF (87.7 to 90.6OC) for a time sufficient to form a uniform, substan-tially homogeneous mixture and to effect pasteuriza-tion, generally for about 20 to 60 minutes;
adding optional heat liable vitamins, such as Vitamin C;
and homogenizing the mixture under conventional elevated pressure conditions at 500 to 5000 psig (35.15 to 351.5 kg/cm2), desirably 1000 to 2000 psig (70.30 to 140.06 40~
kg/cm2) and preferably at 1200 to 1500 psig (84.36 to 105.45 kg/cm2). The homogenized mixture is cooled to about 90 to 120F (32.2 to 48.9C), preferably 110F
(43.3C), and inoculated with a uniquely proportioned blend of standard yogurt cultures.
If it is desired to produce a Swiss style yogurt which has pieces of fruit homogeneously mixed throughout and a predominantly fruity flavor, the inoculated mixture is maintained at this temperature until the desired taste and custard body are achieved, which is usually at a pH of about 3.8 to 4.8, preferably 4.5 to 4.7. The yogurt is then cooled to about 50 to 75F (10 to 23.9C), preferably 65 to 70F (18.3 to 21.1C), and pumped through a small orifice, such as a screw or pressure valve, to break up small pieces of coagulant which are present and to produce a smooth, continuous mass, all as is well known in the art. Low calorie, preferably low carbohydrate fruit preserves are thoroughly blended into the custard, and the resulting product is packaged in suitable individual containers and refrigerated at temperatures sufficiently low to stop fermentation, generally 35 to 50F (1.6 to 10C).
The resulting low calorie and low fat product, which resembles conventional Swiss type yogurt with its smooth, creamy texture and slightly tangy fruity flavor, contains pieces of fruit suspended throughout.
If it is desired to produce Western style yogurt in which a deep layer of plain or unflavored yogurt custard covers a shallow layer of fruit preserves, the inoculated 3L~S~O~
milk-stabilizer-milk solids-vitamin flavorant mixture is pumped into individual containers, such as conventional 8 ounce (224 gram) yogurt containers to which has already been added low calorie fruit preserves, preferably in an amount of about 1.0 ounce (28 grams).
The containers are then maintained at about 90 to 120F
(32.2 to 48.9C), preferably 110F (43.3C) until the desired taste and custard body has been achieved, which is usually when the pH of the yogurt is about 3.8 to 4.8, preferably 4.5 to 4.7, and are then cooled to a temper-ature sufficiently low to stop fermentation, generally 35 to 50 F (1.6 to lO C), Preferably to conventional refrig-eration temperatures, until ready for sale. The resulting low calorie, low fat product has a smooth, creamy custard texture and, unless sweeteners have been added, a typical tart yogurt taste which becomes sweet and predominantly fruity only when the preserves at the bottom are stirred into the yogurt custard. And a still further aspect of -the present invention, there is provided, in a method for making a less than about 0.2% by weight fat, low calorie yogurt product, including the steps of admixing low fat content pasteurized milk, stabilizers and nonfat dry milk solids, heating said mixture to a temperature in the range Erom about 190 to 195F (87.7 to 90.6C), homogenizing said mixture at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2), cooling said homogenized mixture to a temperature of about 90 to 120 F (32.2 to 48.9 C), inoculating said cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture, maintain-,ing said inoculated mixture at a temperature of about 90 to 120 F (32.2 to 48.9 C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in said inoculated mixture, the improvement comprising:
125~40~) - 6a -said lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50%
Lactobacillus acidophilus, balance Lactobacillus -bulgaricus and Streptococcus thermophilus in approximately equal proportions. In a preferred embodiment in the above method, there may be provided the step of combining the inoculated mixture with low calorie fruit preserves either before or after the maintaining step. Still further, in the above, culture mixture, a particularly preferred form is where the culture mixture consists essentially of 40%
Lactobacillus acidophilus, 30% Lactobacillus bulgaricus and 30% Streptococcus thermophilus.
The low calorie, low fat custard-type fruit containing yogurt product of -the presen-t inven-tion comprises a major amount of pasteurized, homogenized cultured skim milk and minor amounts of low calorie fruit preserves, stabilizers, vitamins, minerals and flavorants. Most importantly, the product of the present invention has a total fat content by weight of less than about 0.2%, preferably less than about 0.1%, and contributes only about 150 calories per eight ounce (224 gram) serving to the diet. Desirably, the produc-t has a p~ in the range 4.3 to 4.6, a total solids content of about 19%, and contains up to 20~ by weight fruit.
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Best Mode For Carrying Out The Invention The present invention relates broadly to a low fat -fruit-containing yogurt product which resembles conventional custard-type ~ruit-containing yogurt in appearance, texture and taste, but which has fat and calorie contents substantially reduced below those of conventional yogurt. As a result, the yogurt made by the method of tne present invention is suitable for inclusion in the diets of persons for whom a reduced intake of fat or calories is necessary or desirable.
The overall process by which the fruit-containing yogurt produc-t is made involves admixing pasteurized skim milk, stabilizers and nonfat dry milk solids, e.g., namely nonheat-modified nonfat dry milk solids; adding vitamins and minerals, sweeteners, flavorants and/or colorants to the admixture; heating the resulting mixture to a temperature of about 1900F to 1950F (87.7 to 90.60C) adding optional heat liable vitamins, such as Vitamin C; and homogenization means. The homogenized mixture is then cooled to a temperature of about 90 to 1200F (32.2 to 48.90C), preferably llOoF (43.30C) and inoculated with a uniquely proportioned blend of standard lactic acid producing yogurt cultures. Depending on whether a Swiss type or a Western style yogurt is desired, the inoculated mixture is maintained at this temperature in the bulk mixing vat until the desired taste and texture are achieved, then cooled to about 500 to 750F (10 to 23.90C), pumped through a screw or pressure valve and admixing with fruit preserves prior to packaging and re~rigeration (Swiss style) or placed in conventional yogurt containers to which fruit has already been added and maintained at about llOoF
(43.30C) while in the containers until the product has achieved an acceptable taste and texture before being cooled at conventional refrigeration temperatures (Western style).
0~
In order to prepare a yogurt product having a fat content not greater than about 0.2% by weight the use of fat contributing ingredients must be carefully controlled.
Inasmuch as the primary fat contributing ingredient in yogurt is generally milk, a low fat content may be achieved by selecting a skim milk with a butterfat content of less than about 0.2~ by weight, and preferably less than about 0.1~ by weight, for use in the process of the present invention. The term "milk" as used herein means the 1~ conventional milk of commerce (butterfat content ranging from about 0.1% to 7% by weight) as well as equivalent compositions formed by suitable admixtures of milk solids and water.
The primary carbohydrate contributing ingredients in yogurt are sugars, which may be added to the yogurt custard to flavor it or, more typically, are added in the prepar-ation of the fruit component. Typically, the fruit added to yogurt resembles fruit preserves having discrete pieces of fruit or whole berries in a thickened sugar syrup.
Fruit in this form effectively masks the flavor of the yogurt with a predominantly sweet, fruity taste and is less likely to be fermented by the yogurt bacteria. To prepare a fruit-containing yogurt having a reduced carbohydrate content, the amount of sugar added to the yogurt custard or used in the preparation of the fruit must be carefully regulated. In the past, this has presented a problem since use of less than about 1% by weight of the final product of sucrose, the sugar form most commonly used to prepare fruit for use in yogurt products, does not result in a sufficiently sweet product.
The yogurt products of the present invention can employ a low carbohydrate fruit prepared to resemble the preserves heretofore used in conventional yogurt, but which have been produced with monosaccharide sugars having high sweetening effects, instead of sucrose. For example, the , .
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use of fructose, a monosaccharide with a sweetening effect substantially greater than that of sucrose, to form the syrup results in fruit preserves which are as sweet as those prepared with sucrose but which have a substantially lower carbohydrate level. A preferred fruit preserve preparation which has been found to achieve the desired results contains 40% to 50% by weight fruit pieces or whole berries cooked in a syrup made from invert sugar containing at least 36~ fructose thickened with pectin. The resulting preserves contain about 41% to 47~ solids, are a-t th~
normal pH for the specific fruit used, and contain not more than 825 calories per pound (about 1817 calories per kg) of preserves. Any of the fruits and berries commonly used in conventional fruit-containing yogurt products, such as strawberries, blueberries, cherries and the like, may be prepared for use in the product of the present invention.
The combinati~n of a low level of carbohydrates and a low level of fat results in a yogurt product having signiEi-cantly fewer calories than prior products.
To prepare -the low calorie fruit-containing yogurt of the present invention, pasteurized skim milk having a fat content of less than about 0.2% by weight, preferably less than about 0.1% by weight, is placed in a stainless steel mixing vat or the like container. The skim milk may have been pasteurized by any conventional means, although it is preferred to use skim milk which has been pasteurized by the high temperature, short time (HTST) method. To the skim milk are added stabilizers and nonfat dry milk solids.
A preferred combination of stabilizers which has been found to be successful contains agar, pectin, guar gum and gelatin. However, other commonly used commercially available dairy stabilizers could also be utilized either alone or in combination. The stabilizer or combination of stabilizers comprise less than about 1.0%, preferably about 0.7%, by weight of the final product. The nonfat dry milk . . I
~ ~ . `v' ~5~400 solids comprise up to about 2%, preferably about 1.2%, by weight of the final product. One manner of achieving the low fat, low carbohydrate and low calorie levels of the yogurt of the present invention while obtaining a custard-type produc-t having a creamy consumer acceptable appearance and mouth feel rather than the loose and watery consistency of previously attempted low fat yogurt products, is to use dry milk solids which can be of the heat-modified type or any conventional type, i.e.
non-heat modified - i.e. it has been subjected to no heat treatment prior to spray drying other than pasteurization. Such a modified milk solids product is commercially available from a number of manufacturers.
Examplary of suitable products are "PMC" available from Pro-Mark Co. of Tulsa, Oklahoma, "Hi-Sorb"* available from MPI Division of S-tauffer Chemical Company, Inc. and "Crest Lac"* available from Crest Foods Co., Inc. of Ashton, Illinois. Each of these products is a grade-A
conventional nonfat dry milk product which has been modified primarily by heat for the purpose of increasing the hydration of the pro-tein and for making the product more effective in transmitting texture and flavor. See, for example, U.S.
* Trade Marks - 1 1 125~3~00 Patent No. 4,096,287 for a discussion of acceptable methods for preparing the heat modified non-fat dry milk product by heat treating, other than pasteurization heat treating, including the essential step of non-coagulative direct steam heating of condensed skim milk prior to spray drying for modifying the milk protein.
It has been ~ound convenient to premix the stabili7ers and nonfat dry milk solids in the amounts normally used for production so that the non fat dry milk solids serve as a carrier for the stabilizers. In this connection, as previously indicated, it is acceptable to use admixtures of nonfat dry milk solids and water in lieu of the skim milk in the process of the present invention. If this is done, preparation of the milk starting ingredient must be consistent with the desired 17 to 20~ by weight, preferably about 19% by weight, total solids in the final product.
It is desirable to fortify the fruit-containing yogurt product of the present invention with vitamins and minerals so that an eight ounce (224 gram) serving is nutritionally equivalent to a single serving of milk, which is usually eight ounces (224 gram), and a single serving of fruit, which varie$ according to the kind of fruit. Such fortification, while not essential to the present invention, results in a product of greater nutritional value than a nonfortified product and facilitates the intake of the recommended daily allowances of these vitamins and minerals. Heat labile vitamins and minerals, such as Vitamin C which is destroyed by prolonged high temperatures, should not be added at this stage of the process, but are preferably added at a later time after high temperature heating has taken place.
At this stage in the process, particularly if the end product is to be a Western style yogurt in which the fruit is on the bottom it may be desirable to add - 12 _ ~ 2 5 8 4 00 a sweetener, flavor enhancer or colorant. Addition of one or any combination of these ingredient materials produces a yogur-t custard that is sweet, flavored and/or colored without the frui.t being stirred therethrough. Any sweet-ener used must not, in combination with the sweetenedfruit, exceed the desired carbohydrate level in the final product. It is preferred, therefore, to use as the added sweetener fructose or a similar high sweetening monosac-charide. Any one of a number of commercially available and well known flavor enhancers and/or certified food grade colorings may also be used.
The skim milk-stabilizer-nonfat dry milk solids mixture, which may contain vitamins, minerals, sweeteners, flavorants and/or colorants is heated to a temperature in the range from about 190 to 195F (87.7 to 90.6C.) for a time sufficient to Eorm a uniform, subs-tantially homogen-eous mixture and to pasteurize the'mixture, usually about 20-60 minutes. Heat treating at this high temperature denatures the milk protein, causing water in the mixture to be absorbed and helps to create a thicker, richer product having a custard-type body and texture. The heat labile vitamins and minerals, such as Vitamin C, may be added once the heat treatment at 190-195F (87.7 to 90.6C) is comple-te and the mixture has cooled below the temperature at which the particular vitamin and/or mineral might be adversely affected. The mixture is then homogenized by conventional homogenization means at about 500-5000 psig (35.15 to 351.5 kg/cm2), desirably 1000 to 2000 psig (84.36 to 105.45 kg/cm2), after which it is cooled to an optimum culturing temperature, generally in the range 90 to 120F (32.2 to 48.9C) and preferably about 110F (43.3C) in ~3, 1'~,5~340~
prcparation for )~a(~tcrial i!l~",~ i(,n, -I~]Jvu(Jll t:he temperatuLe may va~y slightly acco~ding to the bacterial culture or cultures used.
The pasteurized, homogenized mixture is - innoculated with a uniquely proportioned blend of lactic acid producing bacterial cultures commonly used in yogurt production in order to confer upon the final yogurt product the proper combination of acidity, tartness and body appropriate for a custard-type yogurt product. Preferred as constituents of the customized 10 yogurt culture for use in the process of the present invention are h~ct__acillu~ bulgaricus, ~eptococcus t_ermo~hil~ and hacto_aCillus acido~hilus. It has been found that when all three of these bacterial cultures are simultaneously employed in predetermined 15 proportions, even very low fat milk-containing mixtures can be cultured to achieve the important custard-type creamy body and mouth feel of conventional yogurt while, at the same time, achieving the desired tartness and acidity. This uniquely proportioned blend of the 20 three aforementioned bacterial cultures is one of the main features of the present invention and the desired yogurt product of the present invention cannot be successfully achieved with other than all three bacterial cultures employed in the following proportions 25 by weight:
Lactobacillus acidophilus 30-50%
~actobacillus k_lgaricus 25-35%
Streptococcus thermophilus 25-35%
The proper combination of cultures is generally 30 determined by the amount of Lactobacillus acidophilus required to culture the low fat milk mixture to a string.y, rubbery body texture which will yield an acceptable custard-type creamy mouth eel. The ~ac~a~illus bulgaricus and ~tre tococcus thermophilus 35 comprise the balance of the culture in about equal proportions.
To this point in the process there is no 84~)0 significant difference in processing between the preparation of Swiss style yogurt, which has a predominantly fruity flavor and contains pieces of fruit uniformly dispersed throughout the yogurt 5 custard, and the preparation of Western style yogurt, which has a shallow layer of fruit preserves on the bottom of the yogurt container covered by a deep layer of yogurt custard. The primary difference in processing the two types is that the Swiss style is 10 cultured in the bulk mixing vat before packaging while the Western style is cultured in the individual containers in which it is packaged.
If a Swiss style yogurt is desired, the cultured mixture is maintained at about 110F. (43.3C.) until a 15 yogurt custard with an acceptable body and taste is produced. Although taste and texture are highly subjective and will vary from producer to producer, experience has shown that when the product reaches a pH
in the range of about 3.8 to 4.8t preferably about 4.5 2Q to 4.7, which typically takes about two to four hours, an acceptably firm yogurt custard with a pleasantly sharp, tangy taste has been produced. When an acceptable product from the standpoint of taste and texture has been produced, the yogurt is cooled to 25 about 50 to 75F. (10 to 23.9C.), preferably about 65 to 70F. (18.3 to 21.1C.), to slow the fermentation while maintaining a sufficiently fluid mixture so that it can be readily pumped through a screw or pressure valve. The cooled mixture is then 30 pumped thro~h a screw or pressure valve to achieve a - smooth texture. Fruit preserves prepared with high sweetening monosaccharides, preferably fructose, are thoroughly blended into the yogurt custard, preferably at a level of about 15% to 20~ by weight fruit in the - 15 _ l~S~0~3 final product. The resulting product is packaged in coventional yogurt containers and held at conventional refrigeration temperatures, preferably about 35 to ~0~. (1.6 to 404C.), to fully terminate fermentation.
- ~- When maintained under conventional refrigeration temperatures, the product has a shelf life of about 30 days.
If a Western style yogurt is desired, about one ounce (28 grams) of fruit preserves prepared with high sweetening monosaccharides, preferably fructose, is 10 placed in the bottom of conventional eight ounce (224 gram) yogurt containers. On top of this is added about seven ounces (196 grams) of the culture-containing, pasteurized, homogenized mixture. The fruit comprises preferably about 15% to 20% by weight of the final 15 product. The filled containers are maintained at about 110F. (43.3C.) until an acceptable taste and texture are produced in the yogurt custard. If a sweetener has been added to the yogurt mixture this may affect somewhat the perception of when an acceptable yogurt 20 taste has been achieved. However, as with the Swiss style yogurt, the notion of what constitutes a suitable product is likely to vary, with acceptable results generally reached when the pH of the product is about 3.8 to 4.8, preferably 4.5 to 4.7. This pH level is 25 generally reached in about two to four hours. The containers are thereafter cooled to and maintained at conventional refrigeration temperatures to stop the fermentation, preferably 35 to 40F. (1.6 to 4.4C.).
Under these conditionsl the product has a shelf life of 30 about 30 days.
The following examples illustrate the practice of the present invention and are intended to exemplify and to limit in any respect the content and scope thereof.
~ ~5840(~
E~ample_l A low calorie, low fat Swiss style yogurt was prepared in the following manner:
2125 pounds (964.75 kg) of MTST
- ~- pasteurized skim milk (less than 0.2% by weight butterfat) was placed in a stainless steel culturing vat equipped with an agitator. To this milk was added 40 pounds (18.16 kg) of a premixed stabilizer-nonfat dry milk mixture which contained about 8 pounds t3.63 kg) of a mixture of agar, pectin, guar gum and gelatin and about 32 pounds (14.53 kg) oF
"PMC" brand heat modified nonfat dry milk solids, and a mixture of vitamins (except Vitamin C) and minerals in quantities which, in the final product, would be the nutritional equivalent to those contained in an 8 ounce (224 gram) serving of milk and an average serving of fruit. The resulting mixture was thoroughly blended and vat pasteurized at 190 to 195F.
(87.7 to 90.6C.) for 30 minutes.
Vitamin C was added and the mixture was homogenized at 1500 psig (105.45 kg/cm2).
The homogenized mixture was then cooled to about 110F. (43.3C.), innoculated with a mixture, by weight, of 40%
hactobacillus ac`dophilius 30%
hactobacillu~ b~l~aricus and 30%
Streptococcus ther_oph lu cultures and maintained in the vat at this temperature until the mixture reached a pH of about 3.8 to 4.8 and had an acceptable custard ~s~o~
consistency. The yogurt was cooled to about 65 to 70F (18.3 to 21.1C) and then pumped through a pressure valve to give it a smoother texture. Five hundred pounds (227 kg) of blueberry preserves having less than 825 calories per pound (1817 calories per kg) were mixed into the yogurt custard. The blueberry pre-serves contained 40% to 50% by weight-whole blueberries in a syrup made from invert sugar con-taining at least 36% to 38% fructose to which pectin had been added to thicken it. The resulting low calorie low fat yogurt had a smooth, creamy texture, contained blueberries uniformly mixed throughout, was the color of blueberries mixed with cream and had a predominantly sweet blueberry taste in combination with a slightly sharp and tangy yogurt taste. The product was packaged in conventional eight ounce yogurt cups, contained 150 calories, 0.2% by weight fat, 12-13% by weight carbohydrate, 4% by weight protein and 19% by weight solids per eight ounce (224 gram) serving, and remained stable for about 30 days at 35 to 40F (1.6 to 4.4C).
Example II
A low calorie, low fat Western style yogurt was prepared in the following manner:
2202 pounds (999.7 kg) of HTST pasteur-ized skim milk (less than 0.2% by weight butterfat) was placed in a , i !
. .
1~5~340(~
stainless steel vat equipped with an agitator. To this milk was added 93 pounds (42.22 kg) of invert sugar which contained 36% to 38% fructose, minor - !~ 5 amounts of flavor enhancers and certified color, 40 pounds (18.16 kg) of the same premixed stabilizer-nonfat dry milk additive used in Example I and a substantially identical mixture of vitamins and minerals as in Example I.
The resulting mixture was thoroughly blended and vat pasteurized to 190 to 195QF. (87.7 to 90.6C.) for 30 minutes~
~itamin C was then added and the mixture was homogenized at 1500 psig (105~45 kg/cm2). The homogenized mixture was cooled to about 110F. (43~3Co) and innoculated with a mixture, by weight of 40% LactQkacillus ncidQ~h lus 30~
2Q hacto~acillus bul~aricus and 30%
~_ eptococcus thermophilus cultures. 335 pounds (152.09 kg) of blueberry preserves in an invert sugar syrup was prepared as described in Example I and one ounce (7-8 grams) of these preserves was pumped into each of a number of conventional eight ounce (224 gram) yogurt cups. The cups were then filled with the innoculated ~ 110F. (43~3C~) homogenized mixture and maintained at 110F. ~43~3C~) until the yogurt reached a pH of about 3.8 to 4.8 and had an acceptable custard consistency. The cups were cooled to 35 to 40F. (1.~ to 4.4C~), at which ~s~o~
temperature the product remained stable for about 30 days. The resulting low calorie and low fat yogurt had a smooth, creamy texture which had a slightly sweet, predominantly sharp yogurt taste before the preserves were stirred u~ from the bottom. This yogurt looked and tasted like the Swiss style and had the same calorie, fat, carbohydrate, protein and solids content.
~;t
Low Calorie, Low Fat Fruit-Containing Yogurt Product and Method for Making Same TECIINICAL FIELD
-The present invention relates generally to a method for making a fruit-containing yogurt product having the appearance, texture and taste of conventional custard-type fruit-containing yogurt and the product thereof;
more specifically the invention relates to a method for making a fruit-containing yogurt product having a fat and calorie content significantly below that of conven-tional fruit-containing yogurt.
BACKGROUND ART
In recent years cultured milk products, referred to as yogurt, have enjoyed immense popularity. The bene-ficial effects on health due to the therapeutic proper-ties of the bacterial cultures contained in yogurt are well known. In addition, yogurt has become a popular food among dieters. To increase its appeal, the sharp, tangy taste charac-teristic of plain, unflavored yogurt, which heretofore made yogurt unacceptable to many people, has been masked in many yogurt products with fruit and sweeteners. This practice has resulted in a flavored yogurt product that is more palatable to a wider segment of the population. However, the use of these additives has been accompanied by an increase in product calorie content from about 90 calories per eight ounce (224 grams) serving of plain, unflavored yogurt to about 250 to 270 calories per eight ounce (224 grams~
serving of the sweetened, fruit-containing yogurt. Such a high ~., .
1~5~0 calorie content renders the fruited product generally unsuitable for inclusion in reducing diets since the fruit yogurt uses up the majority of the calories usually alloted to a single meal. As a result the 5 dieter has~difficulty choosing a sufficient variety or quantity of foods to form a balanced meal within the remaining calories allowed. Accordingly, a need has developed for a fruit-containing yogurt product which is low in calories, fat and carbohydrate content.
1~ Prior methods for producing sweetened or flavored yogurt have succeeded in obtaining a product with a relatively low butterfat content, for example, as low as the 0.5% butterfat content of ordinary skim milk, but none seem to have been able to produce a really low 15 fat, less than about 0.5%, yogurt product having the characteristic creamy custard-type yogurt consistency while at the same time overcoming the high calorie and high carbohydrate problems accompanying the use of fruited or flavored yogurt. One reason for this is 20 that yogurt previously made from really low fat milk products, less than about 0.5% butterfat, has been loose and watery and lacking in flavor rather than creamy and custard-like with consumer acceptable flavor, appearance and mouth feel. Efforts to overcome 25 this problem to obtain a palatable product have either required adding flavor influencing milk solids, which increases the yogurt calorie content, or increasing the milk fat content, which has a similar effect~
Exemplary of prior methods for producing flavored 30 yogurt is U.S. Patent No. 3,969,534 to Pavey et al which teaches the production of a fruited, flavored yogurt which has a relatively low, about 0.5%, butterfat content. However, the product produced by the Pavey method does not appear to be low in _3_ ~ 2 5 B ~o ~
carbohydrates or significantly lower in calories than conventional flavored yogurt. In U.S. Patent No.
3,025,165, Metzger discloses a process for producing yogurt which uses relatively low butterfat starting materials, such as skim milk, to which is added about 1.5% to 6.4~ of an unsaturated vegetable oil. As a result, a higher than desirable fat content for a reducing diet is obtained without significantly reducing the number of calories. Likewise, the fruited yogurt product produced by the process disclosed in U.S. Patent No. 3,269,842 to Mayer et al has a fat content of about 4% and appears to be a high calorie, high carbohydrate product. Donay et al in U.S. Patent No.3,128,190, discloses the use of a skim milk starting material.
However, the process for making Donay's fruit-containing yogurt requires fruit which is precooked with sucrose to prevent fermentation thereof by the yogurt cultures with resultant unpleasant flavors. As a result of this pro-cedure the Donay et al method neither produces really low fat yogurt nor reduces the high calorie and carbo-hydrate content of fruit-containing yogurt. In U.S.
Patent No. 4,110,476, Rhodes discloses a process for preparing liquid, rather than custard-type, yogurt products which utilize whey protein concentrate together with milk products as the starting material ingredients and contain higher sugar contents than are desirable for a fruit-containing yogurt product suitable for a reducing diet.
As disclosed in the prior art e.g., U.S. Patents 3,969,534, 4,096,287 and 4,110,476 (supra) conventional nonfat milk solids can be used in the manufacture of yogurt products.
In the manufacture of yogurt products, however, the use of conventional nonfat milk solids has not resulted in the preparation of satisfactory low calorie yogurt products having acceptable texture and mouth feel. It has been found that it is only when,conventional nonfat milk solids are used in conjunction with the uniquely proportioned blend of three lactic acid producing bac-terial cultures of the present ~5~340~
invention, as is more fulLy described hereinafter, that they con-tribute to -the production of low fat and low calorie yogur-t product having a consumer acceptable consistency, texture and mouth feel with a calorie content significantly below that of known custard-type yogurt products.
Disclosure of the Invention In one form of the present invention there is provided a fruit-containing yogurt product which resembles conventional yogurt in appearance, texture and taste, but which has a fat and calorie content signifi-cantly below that of known custard-type yogurt products.
In yet another form of the present inven-tion there is provided a nutritious, palatable, fruit-containing yogurt product which has the creamy mouth feel and the sweetr fruity, slightly tangy taste of conven-tional custard-type yogurt but which has a fat content below about 0.2~ by weight of the final product.
Another form of the present inven-tion provides a method for making a very low fat and low calorie fruit-containing, custard-type yogurt product.
In accordance with one embodiment of -the present invention there is provided a method for making a less than about 0.2% by weight fat and low calorie yogurt product containing fruit in an amount up to about 20% by weight of the yogurt product and 17 to 20~ by weight total solids, the method comprising -the steps of: (a) admixing pasteurized skim milk having a fat content of less than about 0.2% by weight, stabilizers and an amount of non-heat modified nonfat dry milk solids effective to improve te~ture and flavor, the nonfat dry milk solids having been subjected to no heat treating other than pasteurization heat treating prior to spray drying; ~b) heating the mix-ture to a temperature in the range from about 1900 to 1950F (87.7 to 90.60C) for a time 1~25~34~0 - 4a -sufficient to form a uniform, substantially homogeneous mixture and to effect pasteurization; (c) homogenizing the pas-teurized mixture at pressure in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2); (d) cooling the homogenized mixture to a temperature of about 90 to 1200F (32.2 to 48.90C); (e) inoculating the cooled homogenized mixture ! with a lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50%
Lactobacillus acidophilus, balance Lactobacillus bulgaricu_ and Streptococcus thermophilus in approximately equal proportions; (f) maintaining the inoculated mixture at a -temperature oE about 90 to 1200F (32.3 to 48.90C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in the inoculated mixture; (g) cooling the inoculated mixture; (h) forming the cooled inoculated mixture into a smooth textured product, (i) blending the smooth textured product with low calorie frui-t preserves; and (j) cooling the blend of fruit preserves and smooth textured product to a temperature sufficiently low to stop farmentation.
In accordance with another embodiment of the present invention there is provided a method for making a less than about 0.2% by weight fat and low calorie yogur-t product containing fruit in an amount up to about 20% by weigh-t of the yogurt product and 17 to 20% by weight total solids, the method comprising the steps of: (a) admixing pasteurized skim milk having a fat content of less than about 0.2% by weight, stabilizers and an amount of non-heat modified nonfat dry milk solids effective to improve texture and flavor, the nonfat dry milk solids having been subjected to no heat treating other than pasteurization hea-t treating prior to spray drying; (b) heating the mixture to a temperature in the range from about 190 to 1950F (87.7 to 90.60C) for a time sufficient to form a uniform, substantially homogeneous mix-ture and to effect pas-teurization; (c) homogenizing the pasteurized mixture - 4b -at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2); (d) cooling the homogenized mixture to a temper-ature of about 90 to 1200F (32.2 to 48.90C): (e) inoculating the cooled homogenized mixture with a laetie acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50% Laetobaeillus aeidophilus, balanee Laetobaeillus bulgarieus and Streptocoeeus thermophilus in approximately equal proportions; (f) adding the inoeulated mixture into individual yogurt eontainers eontaining low ealorie ruit preserves; (g) maintaining the fruit preserves and inoe-ulated mixture at a temperature of about 90 to 1200F (32.2 to ~8.90C) for a time suffieient to produee a pH in the ! range of about 3.8 to 4.8 to form an aceeptable taste and texture in inoeulated mixture, and (h) eooling the fruit preserves and inoculated mixture to a temperature sufficiently low to stop fermentation.
In accordance with a further embodiment of the present invention there is provided a low calorie, low fat and fruit-containing yogurt product, characterized in that the yogurt produet has fruit and yogurt to resemble eonventional fruited yogurt in appearanee, texture and taste, and by having a fat content less than about 0.2% by weight of the produet; a fruit eontent of up to about 20%
by weight of the produet; and a calorie content of about 150 calories per eight ounce serving.
In accordanee with a further embodiment of the present invention there is provided a method ~or making a less than about 0.2% by weight fat and low calorie yogurt produet, ineluding the steps of admixing low fa-t eontent pasteurized milk, stabilizers and non-heat modified nonfat dry milk solids, heating the mixture to a temperature in the range from about 190 to 1950F (87.7 to 90.60C), homogenizing the mixture at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/em2), cooling the homogenized mixture to a temperature of about 90 to ~25~3400 - 4c ~
120OF (32.2 to 48.9OC), inoculating the cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture, maintaining the inoculated mixture at a temperature of about 90 to 120OF (32.2 to 48.9OC) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in the inoculated mixture, the improvement comprising the lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50~ Lactobacillus !10 acidophilus, balance Lactobacillus bulgaricus and Streptococcus thermophilus in approximately equal proportions.
In accordance with still a further embodiment of the present invention there is provided a method for making a less than about 0.2~ by weight fat and low calorie yogurt product containing fruit in an amount up -to about 20~ by weight of the yogurt product and 17 to 20% by weight total solids, including the steps of admixing low fat content pasteurized milk, stabilizers and non-heat modified nonfat dry milk solids, heating the mixture to a temperature in the range from about 190 to 195OF (87.7 to 90.6OC), homogenizing the mixture at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2) cooling the homogenized mixture to a temperature of about 90 to 120OF (32.2 to 48.9OC), inoculating the cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture, maintaining the inocu-lated mixture at a temperature of about 90 to 120OF (32.2 to 48.9OC) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in the inoculated mixture and combining the inoculated mixture with low calorie fruit preserves either before or after the maintaining step, the improvement comprising the lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50~ Lactobacillus acidophilus, balance ~s~o~
- 4d -Lactobacillus bulgaricus and Streptococcus thermophilus in approximately equal proportions.
In accordance with one embodiment of the method of the presen-t invention a process for making a low fat, low calorie, fruit-containing yogurt product resembling conventional fruit-containing yogur-t in appearance, texture and taste which includes the steps of admixing pasteurized s~im milk having a fat content of less than about 0.2%, preferably less than about 0.1%, with suitable stabilizers and an amount of nonfat dry milk solids effective to improve texture and flavour; adding optional vitamin and mineral fortification, sweeteners, flavorants and/or colorants; heating the resulting mixture with constant agitation to about 190 to 195OF (87.7 to 90.6OC) for a time sufficient to form a uniform, substan-tially homogeneous mixture and to effect pasteuriza-tion, generally for about 20 to 60 minutes;
adding optional heat liable vitamins, such as Vitamin C;
and homogenizing the mixture under conventional elevated pressure conditions at 500 to 5000 psig (35.15 to 351.5 kg/cm2), desirably 1000 to 2000 psig (70.30 to 140.06 40~
kg/cm2) and preferably at 1200 to 1500 psig (84.36 to 105.45 kg/cm2). The homogenized mixture is cooled to about 90 to 120F (32.2 to 48.9C), preferably 110F
(43.3C), and inoculated with a uniquely proportioned blend of standard yogurt cultures.
If it is desired to produce a Swiss style yogurt which has pieces of fruit homogeneously mixed throughout and a predominantly fruity flavor, the inoculated mixture is maintained at this temperature until the desired taste and custard body are achieved, which is usually at a pH of about 3.8 to 4.8, preferably 4.5 to 4.7. The yogurt is then cooled to about 50 to 75F (10 to 23.9C), preferably 65 to 70F (18.3 to 21.1C), and pumped through a small orifice, such as a screw or pressure valve, to break up small pieces of coagulant which are present and to produce a smooth, continuous mass, all as is well known in the art. Low calorie, preferably low carbohydrate fruit preserves are thoroughly blended into the custard, and the resulting product is packaged in suitable individual containers and refrigerated at temperatures sufficiently low to stop fermentation, generally 35 to 50F (1.6 to 10C).
The resulting low calorie and low fat product, which resembles conventional Swiss type yogurt with its smooth, creamy texture and slightly tangy fruity flavor, contains pieces of fruit suspended throughout.
If it is desired to produce Western style yogurt in which a deep layer of plain or unflavored yogurt custard covers a shallow layer of fruit preserves, the inoculated 3L~S~O~
milk-stabilizer-milk solids-vitamin flavorant mixture is pumped into individual containers, such as conventional 8 ounce (224 gram) yogurt containers to which has already been added low calorie fruit preserves, preferably in an amount of about 1.0 ounce (28 grams).
The containers are then maintained at about 90 to 120F
(32.2 to 48.9C), preferably 110F (43.3C) until the desired taste and custard body has been achieved, which is usually when the pH of the yogurt is about 3.8 to 4.8, preferably 4.5 to 4.7, and are then cooled to a temper-ature sufficiently low to stop fermentation, generally 35 to 50 F (1.6 to lO C), Preferably to conventional refrig-eration temperatures, until ready for sale. The resulting low calorie, low fat product has a smooth, creamy custard texture and, unless sweeteners have been added, a typical tart yogurt taste which becomes sweet and predominantly fruity only when the preserves at the bottom are stirred into the yogurt custard. And a still further aspect of -the present invention, there is provided, in a method for making a less than about 0.2% by weight fat, low calorie yogurt product, including the steps of admixing low fat content pasteurized milk, stabilizers and nonfat dry milk solids, heating said mixture to a temperature in the range Erom about 190 to 195F (87.7 to 90.6C), homogenizing said mixture at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2), cooling said homogenized mixture to a temperature of about 90 to 120 F (32.2 to 48.9 C), inoculating said cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture, maintain-,ing said inoculated mixture at a temperature of about 90 to 120 F (32.2 to 48.9 C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in said inoculated mixture, the improvement comprising:
125~40~) - 6a -said lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50%
Lactobacillus acidophilus, balance Lactobacillus -bulgaricus and Streptococcus thermophilus in approximately equal proportions. In a preferred embodiment in the above method, there may be provided the step of combining the inoculated mixture with low calorie fruit preserves either before or after the maintaining step. Still further, in the above, culture mixture, a particularly preferred form is where the culture mixture consists essentially of 40%
Lactobacillus acidophilus, 30% Lactobacillus bulgaricus and 30% Streptococcus thermophilus.
The low calorie, low fat custard-type fruit containing yogurt product of -the presen-t inven-tion comprises a major amount of pasteurized, homogenized cultured skim milk and minor amounts of low calorie fruit preserves, stabilizers, vitamins, minerals and flavorants. Most importantly, the product of the present invention has a total fat content by weight of less than about 0.2%, preferably less than about 0.1%, and contributes only about 150 calories per eight ounce (224 gram) serving to the diet. Desirably, the produc-t has a p~ in the range 4.3 to 4.6, a total solids content of about 19%, and contains up to 20~ by weight fruit.
~s .~
~ ~58~0~
Best Mode For Carrying Out The Invention The present invention relates broadly to a low fat -fruit-containing yogurt product which resembles conventional custard-type ~ruit-containing yogurt in appearance, texture and taste, but which has fat and calorie contents substantially reduced below those of conventional yogurt. As a result, the yogurt made by the method of tne present invention is suitable for inclusion in the diets of persons for whom a reduced intake of fat or calories is necessary or desirable.
The overall process by which the fruit-containing yogurt produc-t is made involves admixing pasteurized skim milk, stabilizers and nonfat dry milk solids, e.g., namely nonheat-modified nonfat dry milk solids; adding vitamins and minerals, sweeteners, flavorants and/or colorants to the admixture; heating the resulting mixture to a temperature of about 1900F to 1950F (87.7 to 90.60C) adding optional heat liable vitamins, such as Vitamin C; and homogenization means. The homogenized mixture is then cooled to a temperature of about 90 to 1200F (32.2 to 48.90C), preferably llOoF (43.30C) and inoculated with a uniquely proportioned blend of standard lactic acid producing yogurt cultures. Depending on whether a Swiss type or a Western style yogurt is desired, the inoculated mixture is maintained at this temperature in the bulk mixing vat until the desired taste and texture are achieved, then cooled to about 500 to 750F (10 to 23.90C), pumped through a screw or pressure valve and admixing with fruit preserves prior to packaging and re~rigeration (Swiss style) or placed in conventional yogurt containers to which fruit has already been added and maintained at about llOoF
(43.30C) while in the containers until the product has achieved an acceptable taste and texture before being cooled at conventional refrigeration temperatures (Western style).
0~
In order to prepare a yogurt product having a fat content not greater than about 0.2% by weight the use of fat contributing ingredients must be carefully controlled.
Inasmuch as the primary fat contributing ingredient in yogurt is generally milk, a low fat content may be achieved by selecting a skim milk with a butterfat content of less than about 0.2~ by weight, and preferably less than about 0.1~ by weight, for use in the process of the present invention. The term "milk" as used herein means the 1~ conventional milk of commerce (butterfat content ranging from about 0.1% to 7% by weight) as well as equivalent compositions formed by suitable admixtures of milk solids and water.
The primary carbohydrate contributing ingredients in yogurt are sugars, which may be added to the yogurt custard to flavor it or, more typically, are added in the prepar-ation of the fruit component. Typically, the fruit added to yogurt resembles fruit preserves having discrete pieces of fruit or whole berries in a thickened sugar syrup.
Fruit in this form effectively masks the flavor of the yogurt with a predominantly sweet, fruity taste and is less likely to be fermented by the yogurt bacteria. To prepare a fruit-containing yogurt having a reduced carbohydrate content, the amount of sugar added to the yogurt custard or used in the preparation of the fruit must be carefully regulated. In the past, this has presented a problem since use of less than about 1% by weight of the final product of sucrose, the sugar form most commonly used to prepare fruit for use in yogurt products, does not result in a sufficiently sweet product.
The yogurt products of the present invention can employ a low carbohydrate fruit prepared to resemble the preserves heretofore used in conventional yogurt, but which have been produced with monosaccharide sugars having high sweetening effects, instead of sucrose. For example, the , .
~Y,~
~s~
use of fructose, a monosaccharide with a sweetening effect substantially greater than that of sucrose, to form the syrup results in fruit preserves which are as sweet as those prepared with sucrose but which have a substantially lower carbohydrate level. A preferred fruit preserve preparation which has been found to achieve the desired results contains 40% to 50% by weight fruit pieces or whole berries cooked in a syrup made from invert sugar containing at least 36~ fructose thickened with pectin. The resulting preserves contain about 41% to 47~ solids, are a-t th~
normal pH for the specific fruit used, and contain not more than 825 calories per pound (about 1817 calories per kg) of preserves. Any of the fruits and berries commonly used in conventional fruit-containing yogurt products, such as strawberries, blueberries, cherries and the like, may be prepared for use in the product of the present invention.
The combinati~n of a low level of carbohydrates and a low level of fat results in a yogurt product having signiEi-cantly fewer calories than prior products.
To prepare -the low calorie fruit-containing yogurt of the present invention, pasteurized skim milk having a fat content of less than about 0.2% by weight, preferably less than about 0.1% by weight, is placed in a stainless steel mixing vat or the like container. The skim milk may have been pasteurized by any conventional means, although it is preferred to use skim milk which has been pasteurized by the high temperature, short time (HTST) method. To the skim milk are added stabilizers and nonfat dry milk solids.
A preferred combination of stabilizers which has been found to be successful contains agar, pectin, guar gum and gelatin. However, other commonly used commercially available dairy stabilizers could also be utilized either alone or in combination. The stabilizer or combination of stabilizers comprise less than about 1.0%, preferably about 0.7%, by weight of the final product. The nonfat dry milk . . I
~ ~ . `v' ~5~400 solids comprise up to about 2%, preferably about 1.2%, by weight of the final product. One manner of achieving the low fat, low carbohydrate and low calorie levels of the yogurt of the present invention while obtaining a custard-type produc-t having a creamy consumer acceptable appearance and mouth feel rather than the loose and watery consistency of previously attempted low fat yogurt products, is to use dry milk solids which can be of the heat-modified type or any conventional type, i.e.
non-heat modified - i.e. it has been subjected to no heat treatment prior to spray drying other than pasteurization. Such a modified milk solids product is commercially available from a number of manufacturers.
Examplary of suitable products are "PMC" available from Pro-Mark Co. of Tulsa, Oklahoma, "Hi-Sorb"* available from MPI Division of S-tauffer Chemical Company, Inc. and "Crest Lac"* available from Crest Foods Co., Inc. of Ashton, Illinois. Each of these products is a grade-A
conventional nonfat dry milk product which has been modified primarily by heat for the purpose of increasing the hydration of the pro-tein and for making the product more effective in transmitting texture and flavor. See, for example, U.S.
* Trade Marks - 1 1 125~3~00 Patent No. 4,096,287 for a discussion of acceptable methods for preparing the heat modified non-fat dry milk product by heat treating, other than pasteurization heat treating, including the essential step of non-coagulative direct steam heating of condensed skim milk prior to spray drying for modifying the milk protein.
It has been ~ound convenient to premix the stabili7ers and nonfat dry milk solids in the amounts normally used for production so that the non fat dry milk solids serve as a carrier for the stabilizers. In this connection, as previously indicated, it is acceptable to use admixtures of nonfat dry milk solids and water in lieu of the skim milk in the process of the present invention. If this is done, preparation of the milk starting ingredient must be consistent with the desired 17 to 20~ by weight, preferably about 19% by weight, total solids in the final product.
It is desirable to fortify the fruit-containing yogurt product of the present invention with vitamins and minerals so that an eight ounce (224 gram) serving is nutritionally equivalent to a single serving of milk, which is usually eight ounces (224 gram), and a single serving of fruit, which varie$ according to the kind of fruit. Such fortification, while not essential to the present invention, results in a product of greater nutritional value than a nonfortified product and facilitates the intake of the recommended daily allowances of these vitamins and minerals. Heat labile vitamins and minerals, such as Vitamin C which is destroyed by prolonged high temperatures, should not be added at this stage of the process, but are preferably added at a later time after high temperature heating has taken place.
At this stage in the process, particularly if the end product is to be a Western style yogurt in which the fruit is on the bottom it may be desirable to add - 12 _ ~ 2 5 8 4 00 a sweetener, flavor enhancer or colorant. Addition of one or any combination of these ingredient materials produces a yogur-t custard that is sweet, flavored and/or colored without the frui.t being stirred therethrough. Any sweet-ener used must not, in combination with the sweetenedfruit, exceed the desired carbohydrate level in the final product. It is preferred, therefore, to use as the added sweetener fructose or a similar high sweetening monosac-charide. Any one of a number of commercially available and well known flavor enhancers and/or certified food grade colorings may also be used.
The skim milk-stabilizer-nonfat dry milk solids mixture, which may contain vitamins, minerals, sweeteners, flavorants and/or colorants is heated to a temperature in the range from about 190 to 195F (87.7 to 90.6C.) for a time sufficient to Eorm a uniform, subs-tantially homogen-eous mixture and to pasteurize the'mixture, usually about 20-60 minutes. Heat treating at this high temperature denatures the milk protein, causing water in the mixture to be absorbed and helps to create a thicker, richer product having a custard-type body and texture. The heat labile vitamins and minerals, such as Vitamin C, may be added once the heat treatment at 190-195F (87.7 to 90.6C) is comple-te and the mixture has cooled below the temperature at which the particular vitamin and/or mineral might be adversely affected. The mixture is then homogenized by conventional homogenization means at about 500-5000 psig (35.15 to 351.5 kg/cm2), desirably 1000 to 2000 psig (84.36 to 105.45 kg/cm2), after which it is cooled to an optimum culturing temperature, generally in the range 90 to 120F (32.2 to 48.9C) and preferably about 110F (43.3C) in ~3, 1'~,5~340~
prcparation for )~a(~tcrial i!l~",~ i(,n, -I~]Jvu(Jll t:he temperatuLe may va~y slightly acco~ding to the bacterial culture or cultures used.
The pasteurized, homogenized mixture is - innoculated with a uniquely proportioned blend of lactic acid producing bacterial cultures commonly used in yogurt production in order to confer upon the final yogurt product the proper combination of acidity, tartness and body appropriate for a custard-type yogurt product. Preferred as constituents of the customized 10 yogurt culture for use in the process of the present invention are h~ct__acillu~ bulgaricus, ~eptococcus t_ermo~hil~ and hacto_aCillus acido~hilus. It has been found that when all three of these bacterial cultures are simultaneously employed in predetermined 15 proportions, even very low fat milk-containing mixtures can be cultured to achieve the important custard-type creamy body and mouth feel of conventional yogurt while, at the same time, achieving the desired tartness and acidity. This uniquely proportioned blend of the 20 three aforementioned bacterial cultures is one of the main features of the present invention and the desired yogurt product of the present invention cannot be successfully achieved with other than all three bacterial cultures employed in the following proportions 25 by weight:
Lactobacillus acidophilus 30-50%
~actobacillus k_lgaricus 25-35%
Streptococcus thermophilus 25-35%
The proper combination of cultures is generally 30 determined by the amount of Lactobacillus acidophilus required to culture the low fat milk mixture to a string.y, rubbery body texture which will yield an acceptable custard-type creamy mouth eel. The ~ac~a~illus bulgaricus and ~tre tococcus thermophilus 35 comprise the balance of the culture in about equal proportions.
To this point in the process there is no 84~)0 significant difference in processing between the preparation of Swiss style yogurt, which has a predominantly fruity flavor and contains pieces of fruit uniformly dispersed throughout the yogurt 5 custard, and the preparation of Western style yogurt, which has a shallow layer of fruit preserves on the bottom of the yogurt container covered by a deep layer of yogurt custard. The primary difference in processing the two types is that the Swiss style is 10 cultured in the bulk mixing vat before packaging while the Western style is cultured in the individual containers in which it is packaged.
If a Swiss style yogurt is desired, the cultured mixture is maintained at about 110F. (43.3C.) until a 15 yogurt custard with an acceptable body and taste is produced. Although taste and texture are highly subjective and will vary from producer to producer, experience has shown that when the product reaches a pH
in the range of about 3.8 to 4.8t preferably about 4.5 2Q to 4.7, which typically takes about two to four hours, an acceptably firm yogurt custard with a pleasantly sharp, tangy taste has been produced. When an acceptable product from the standpoint of taste and texture has been produced, the yogurt is cooled to 25 about 50 to 75F. (10 to 23.9C.), preferably about 65 to 70F. (18.3 to 21.1C.), to slow the fermentation while maintaining a sufficiently fluid mixture so that it can be readily pumped through a screw or pressure valve. The cooled mixture is then 30 pumped thro~h a screw or pressure valve to achieve a - smooth texture. Fruit preserves prepared with high sweetening monosaccharides, preferably fructose, are thoroughly blended into the yogurt custard, preferably at a level of about 15% to 20~ by weight fruit in the - 15 _ l~S~0~3 final product. The resulting product is packaged in coventional yogurt containers and held at conventional refrigeration temperatures, preferably about 35 to ~0~. (1.6 to 404C.), to fully terminate fermentation.
- ~- When maintained under conventional refrigeration temperatures, the product has a shelf life of about 30 days.
If a Western style yogurt is desired, about one ounce (28 grams) of fruit preserves prepared with high sweetening monosaccharides, preferably fructose, is 10 placed in the bottom of conventional eight ounce (224 gram) yogurt containers. On top of this is added about seven ounces (196 grams) of the culture-containing, pasteurized, homogenized mixture. The fruit comprises preferably about 15% to 20% by weight of the final 15 product. The filled containers are maintained at about 110F. (43.3C.) until an acceptable taste and texture are produced in the yogurt custard. If a sweetener has been added to the yogurt mixture this may affect somewhat the perception of when an acceptable yogurt 20 taste has been achieved. However, as with the Swiss style yogurt, the notion of what constitutes a suitable product is likely to vary, with acceptable results generally reached when the pH of the product is about 3.8 to 4.8, preferably 4.5 to 4.7. This pH level is 25 generally reached in about two to four hours. The containers are thereafter cooled to and maintained at conventional refrigeration temperatures to stop the fermentation, preferably 35 to 40F. (1.6 to 4.4C.).
Under these conditionsl the product has a shelf life of 30 about 30 days.
The following examples illustrate the practice of the present invention and are intended to exemplify and to limit in any respect the content and scope thereof.
~ ~5840(~
E~ample_l A low calorie, low fat Swiss style yogurt was prepared in the following manner:
2125 pounds (964.75 kg) of MTST
- ~- pasteurized skim milk (less than 0.2% by weight butterfat) was placed in a stainless steel culturing vat equipped with an agitator. To this milk was added 40 pounds (18.16 kg) of a premixed stabilizer-nonfat dry milk mixture which contained about 8 pounds t3.63 kg) of a mixture of agar, pectin, guar gum and gelatin and about 32 pounds (14.53 kg) oF
"PMC" brand heat modified nonfat dry milk solids, and a mixture of vitamins (except Vitamin C) and minerals in quantities which, in the final product, would be the nutritional equivalent to those contained in an 8 ounce (224 gram) serving of milk and an average serving of fruit. The resulting mixture was thoroughly blended and vat pasteurized at 190 to 195F.
(87.7 to 90.6C.) for 30 minutes.
Vitamin C was added and the mixture was homogenized at 1500 psig (105.45 kg/cm2).
The homogenized mixture was then cooled to about 110F. (43.3C.), innoculated with a mixture, by weight, of 40%
hactobacillus ac`dophilius 30%
hactobacillu~ b~l~aricus and 30%
Streptococcus ther_oph lu cultures and maintained in the vat at this temperature until the mixture reached a pH of about 3.8 to 4.8 and had an acceptable custard ~s~o~
consistency. The yogurt was cooled to about 65 to 70F (18.3 to 21.1C) and then pumped through a pressure valve to give it a smoother texture. Five hundred pounds (227 kg) of blueberry preserves having less than 825 calories per pound (1817 calories per kg) were mixed into the yogurt custard. The blueberry pre-serves contained 40% to 50% by weight-whole blueberries in a syrup made from invert sugar con-taining at least 36% to 38% fructose to which pectin had been added to thicken it. The resulting low calorie low fat yogurt had a smooth, creamy texture, contained blueberries uniformly mixed throughout, was the color of blueberries mixed with cream and had a predominantly sweet blueberry taste in combination with a slightly sharp and tangy yogurt taste. The product was packaged in conventional eight ounce yogurt cups, contained 150 calories, 0.2% by weight fat, 12-13% by weight carbohydrate, 4% by weight protein and 19% by weight solids per eight ounce (224 gram) serving, and remained stable for about 30 days at 35 to 40F (1.6 to 4.4C).
Example II
A low calorie, low fat Western style yogurt was prepared in the following manner:
2202 pounds (999.7 kg) of HTST pasteur-ized skim milk (less than 0.2% by weight butterfat) was placed in a , i !
. .
1~5~340(~
stainless steel vat equipped with an agitator. To this milk was added 93 pounds (42.22 kg) of invert sugar which contained 36% to 38% fructose, minor - !~ 5 amounts of flavor enhancers and certified color, 40 pounds (18.16 kg) of the same premixed stabilizer-nonfat dry milk additive used in Example I and a substantially identical mixture of vitamins and minerals as in Example I.
The resulting mixture was thoroughly blended and vat pasteurized to 190 to 195QF. (87.7 to 90.6C.) for 30 minutes~
~itamin C was then added and the mixture was homogenized at 1500 psig (105~45 kg/cm2). The homogenized mixture was cooled to about 110F. (43~3Co) and innoculated with a mixture, by weight of 40% LactQkacillus ncidQ~h lus 30~
2Q hacto~acillus bul~aricus and 30%
~_ eptococcus thermophilus cultures. 335 pounds (152.09 kg) of blueberry preserves in an invert sugar syrup was prepared as described in Example I and one ounce (7-8 grams) of these preserves was pumped into each of a number of conventional eight ounce (224 gram) yogurt cups. The cups were then filled with the innoculated ~ 110F. (43~3C~) homogenized mixture and maintained at 110F. ~43~3C~) until the yogurt reached a pH of about 3.8 to 4.8 and had an acceptable custard consistency. The cups were cooled to 35 to 40F. (1.~ to 4.4C~), at which ~s~o~
temperature the product remained stable for about 30 days. The resulting low calorie and low fat yogurt had a smooth, creamy texture which had a slightly sweet, predominantly sharp yogurt taste before the preserves were stirred u~ from the bottom. This yogurt looked and tasted like the Swiss style and had the same calorie, fat, carbohydrate, protein and solids content.
~;t
Claims (27)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS
1. A method for making a less than about 0.2% by weight fat and low calorie yogurt product containing fruit in an amount up to about 20% by weight of the yogurt product and 17 to 20% by weight total solids, said method comprising the steps of:
(a) admixing pasteurized skim milk having a fat content of less than about 0.2% by weight, stabilizers and an amount of non-heat modified nonfat dry milk solids effective to improve texture and flavor, said nonfat dry milk solids having been subjected to no heat treating other than pasteurization heat treating prior to spray drying;
(b) heating said mixture to a temperature in the range from about 190 to 195°F (87.7 to 90.6°C) for a time sufficient to form a uniform, substantially homogeneous mixture and to effect pasteurization;
(c) homogenizing said pasteurized mixture at pressure in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2);
(d) cooling said homogenized mixture to a temper-ature of about 90 to 120°F (32.2 to 48.9°C);
(e) inoculating said cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50 Lactobacillus acidophilus, balance Lactobacillus bulgaricus and Streptococcus thermophilus in approxi-mately equal proportions;
(f) maintaining said inoculated mixture at a temperature of about 90 to 120°F (32.3 to 48.9°C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in said inoculated mixture;
(g) cooling said inoculated mixture;
(h) forming said cooled inoculated mixture into a smooth textured product;
(i) blending said smooth textured product with low calorie fruit preserves; and (j) cooling said blend of fruit preserves and smooth textured product to a temperature sufficiently low to stop fermentation.
(a) admixing pasteurized skim milk having a fat content of less than about 0.2% by weight, stabilizers and an amount of non-heat modified nonfat dry milk solids effective to improve texture and flavor, said nonfat dry milk solids having been subjected to no heat treating other than pasteurization heat treating prior to spray drying;
(b) heating said mixture to a temperature in the range from about 190 to 195°F (87.7 to 90.6°C) for a time sufficient to form a uniform, substantially homogeneous mixture and to effect pasteurization;
(c) homogenizing said pasteurized mixture at pressure in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2);
(d) cooling said homogenized mixture to a temper-ature of about 90 to 120°F (32.2 to 48.9°C);
(e) inoculating said cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50 Lactobacillus acidophilus, balance Lactobacillus bulgaricus and Streptococcus thermophilus in approxi-mately equal proportions;
(f) maintaining said inoculated mixture at a temperature of about 90 to 120°F (32.3 to 48.9°C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in said inoculated mixture;
(g) cooling said inoculated mixture;
(h) forming said cooled inoculated mixture into a smooth textured product;
(i) blending said smooth textured product with low calorie fruit preserves; and (j) cooling said blend of fruit preserves and smooth textured product to a temperature sufficiently low to stop fermentation.
2. A method for making a less than about 0.2% by weight fat and low calorie yogurt product containing fruit in an amount up to about 20% by weight of the yogurt product and 17 to 20% by weight total solids, said method comprising the steps of:
(a) admixing pasteurized skim milk having a fat content of less than about 0.2% by weight, stabilizers and an amount of non-heat modified nonfat dry milk solids effective to improve texture and flavor, said nonfat dry milk solids having been subjected to no heat treating other than pasteurization heat treating prior to spray drying;
(b) heating said mixture to a temperature in the range from about 190 to 195°F (87.7 to 90.6°C) for a time sufficient to form a uniform, substantially homogeneous mixture and to effect pasteurization;
(c) homogenizing said pasteurized mixture at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2);
(d) cooling said homogenized mixture to a temper-ature of about 90 to 120°F (32.2 to 48.9°C);
(e) inoculating said cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50%
Lactobacillus acidophilus, balance Lactobacillus bulqaricus and Streptococcus thermophilus in approxi-mately equal proportions;
(f) adding said inoculated mixture into individual yogurt containers containing low calorie fruit preserves;
(g) maintaining said fruit preserves and inoc-ulated mixture at a temperature of about 90 to 120°F
(32.2 to 48.9°C) for a time sufficient to produce a pH
in the range of about 3.8 to 4.8 to form an acceptable taste and texture in said inoculated mixture; and (h) cooling said fruit preserves and inoculated mixture to a temperature sufficiently low to stop fermentation
(a) admixing pasteurized skim milk having a fat content of less than about 0.2% by weight, stabilizers and an amount of non-heat modified nonfat dry milk solids effective to improve texture and flavor, said nonfat dry milk solids having been subjected to no heat treating other than pasteurization heat treating prior to spray drying;
(b) heating said mixture to a temperature in the range from about 190 to 195°F (87.7 to 90.6°C) for a time sufficient to form a uniform, substantially homogeneous mixture and to effect pasteurization;
(c) homogenizing said pasteurized mixture at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2);
(d) cooling said homogenized mixture to a temper-ature of about 90 to 120°F (32.2 to 48.9°C);
(e) inoculating said cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50%
Lactobacillus acidophilus, balance Lactobacillus bulqaricus and Streptococcus thermophilus in approxi-mately equal proportions;
(f) adding said inoculated mixture into individual yogurt containers containing low calorie fruit preserves;
(g) maintaining said fruit preserves and inoc-ulated mixture at a temperature of about 90 to 120°F
(32.2 to 48.9°C) for a time sufficient to produce a pH
in the range of about 3.8 to 4.8 to form an acceptable taste and texture in said inoculated mixture; and (h) cooling said fruit preserves and inoculated mixture to a temperature sufficiently low to stop fermentation
3. A method, as claimed in claim 2, wherein said low calorie fruit preserves comprise about 40% to 50%
by weight of fruit and a syrup for said fruit.
by weight of fruit and a syrup for said fruit.
4. A method, as claimed in claim 3, wherein said low calorie fruit preserves comprise about 40% to 50%
by weight of fruit and a syrup for said fruit.
by weight of fruit and a syrup for said fruit.
5. A method, as claimed in claims 1 or 2, wherein said skim milk has a fat content of less than about 0.1% by weight.
6. A method, as claimed, in claims 3 or 4, wherein said skim milk has a fat content of less than about 0.1% by weight.
7 A method, as claimed in claims 1 or 2, wherein the pH produced in said inoculated mixture is in the range of about 4.5 to 4.7.
8. A method, as claimed in claims 3 or 4 , wherein the pH produced in said inoculated mixture is in the range of about 4.5 to 4.7.
9. A method, as claimed in claims 1 or 2, wherein said time sufficient in step (b) is from about 20 to 60 minutes.
10. A method, as claimed in claims 3 or 4, wherein said time sufficient in step (b) is from about 20 to 60 minutes.
11. A method, as claimed in claims 1 or 2, wherein said homogenizing is practiced in the pressure range 1000 to 2000 psig (70.03 to 140.06 kg/cm2).
12. A method, as claimed in claims 3 or 4, wherein said homogenizing is practiced in the pressure range 1000 to 2000 psig (70.03 to 140.06 kg/cm2).
13. A method, as claimed in claims 1 or 2, wherein said temperature sufficiently low to stop fermentation is in the range from 35 to about 50°F (1.6 to 10°C).
14. A method, as claimed in claims 3 or 4, wherein said temperature sufficiently low to stop fermentation is in the range from 35 to about 50°F (1.6 to 10°C).
15. A method, as claimed in claims 1 or 2, wherein said temperature sufficiently low to stop fermentation is in the range from 35 to 40°F (1.6 to 4.4°C).
16. A method, as claimed in claims 3 or 4, wherein said temperature sufficiently low to stop fermentation is in the range from 35 to 40°F (1.6 to 4.4°C).
17. A low calorie, low fat and fruit-containing yogurt product, characterized in that the yogurt product has fruit and yogurt to resemble conventional fruited yogurt in appearance, texture and taste, and by having a fat content less than about 0.2% by weight of said product; a fruit content of up to about 20% by weight of said product; and a calorie content of about 150 cal-ories per eight ounce serving.
18. A yogurt product, as claimed in claim 17, wherein said product has been prepared with lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30 to 50% Lactobacillus acidophilus, balance Lactobacillus bulgaricus and Streptococcus thermophilus in approximately equal proportions.
19. A yogurt product, as claimed in claim 17, wherein said product has been prepared with pasteurized skim milk having a fat content of less than about 0.2%
by weight, stabilizers and an amount of non-heat modi-fied nonfat dry milk solids effective to improve texture and flavor, said nonfat dry milk solids having been sub-jected to no heat treating other than pasteurization heat treating prior to spray drying.
by weight, stabilizers and an amount of non-heat modi-fied nonfat dry milk solids effective to improve texture and flavor, said nonfat dry milk solids having been sub-jected to no heat treating other than pasteurization heat treating prior to spray drying.
20. A yogurt product, as claimed in claim 19, wherein said fruit comprises low calorie fruit preserves comprising about 40 to 50% by weight of fruit and a syrup for said fruit.
21. A yogurt product, as claimed in claim 20, wherein said skim milk is admixed with said stabilizers and said nonfat dry milk solids; said mixture is heated to a temperature in the range from about 190 to 195°F
(87.7 to 90.6°C) for a time sufficient to form a uni-form, substantially, homogeneous mixture and to effect pasteurization; said pasteurized mixture is homogenized at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2); said homogenized mixture is cooled to a temperature of about 90 to 120°F (32.2 to 48.9°C); and, wherein said cooled homogenized mixture is inoculated with said lactic acid producing bacterial yogurt culture mixture; said inoculated mixture is maintained at a temperature of about 90 to 120°F (32.3 to 48.9°C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in said inoculated mixture; said inoculated mixture is cooled to a temperature in the range 50 to 75°F (10 to 23.9°C); said cooled inoculated mixture is formed into a smooth textured product; said smooth textured product is blended with said low calorie fruit preserves; and said blend of fruit preserves and smooth textured product is cooled to a temperature sufficiently low to stop fermentation.
(87.7 to 90.6°C) for a time sufficient to form a uni-form, substantially, homogeneous mixture and to effect pasteurization; said pasteurized mixture is homogenized at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2); said homogenized mixture is cooled to a temperature of about 90 to 120°F (32.2 to 48.9°C); and, wherein said cooled homogenized mixture is inoculated with said lactic acid producing bacterial yogurt culture mixture; said inoculated mixture is maintained at a temperature of about 90 to 120°F (32.3 to 48.9°C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in said inoculated mixture; said inoculated mixture is cooled to a temperature in the range 50 to 75°F (10 to 23.9°C); said cooled inoculated mixture is formed into a smooth textured product; said smooth textured product is blended with said low calorie fruit preserves; and said blend of fruit preserves and smooth textured product is cooled to a temperature sufficiently low to stop fermentation.
22. A yogurt product, as claimed in claim 20, wherein said skim milk is admixed with said stabilizers and said nonfat dry milk solids; said mixture is heated to a temperature in the range from about 190° to 195°F (87.7 to 90.6°C) for a time sufficient to form a uniform, substantially, homogeneous mixture and to effect pasteur-ization; said pasteurized mixture is homogenized at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2); said homogenized mixture is cooled to a temper-ature of about 90 to 120°F (32.2 to 48.9°C); and, wherein said cooled homogenized mixture is inoculated with said lactic acid producing bacterial yogurt culture mixture;
said inoculated mixture is added to individual yogurt containers containing low calorie fruit preserves; said inoculated mixture and fruit preserves are maintained at a temperature of about 90 to 120°F (32.2 to 48.9°C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in said inoculated mixture; and said inoculated mixture and fruit preserves are cooled to a temperature sufficiently low to stop fermentation.
said inoculated mixture is added to individual yogurt containers containing low calorie fruit preserves; said inoculated mixture and fruit preserves are maintained at a temperature of about 90 to 120°F (32.2 to 48.9°C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in said inoculated mixture; and said inoculated mixture and fruit preserves are cooled to a temperature sufficiently low to stop fermentation.
23. A yogurt product, as claimed in claim 17, wherein the fat content in said product is less than about 0.1% by weight of said product.
24. A yogurt product, as claimed in claim 17 or 23, wherein the total solids content in said product is in the range 17 to 20% by weight.
25. In a method for making a less than about 0.2% by weight fat and low calorie yogurt product, including the steps of admixing low fat content pasteurized milk, stabil-izers and non-heat modified nonfat dry milk solids, heating said mixture to a temperature in the range from about 190 to 195°F (87.7 to 90.6°C), homogenizing said mixture at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm2), cooling said homogenized mixture to a temperature of about 90 to 120°F (32.2 to 48.9°C), inoculating said cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture, maintaining said inoculated mixture at a temperature of about 90 to 120°F
(32.2 to 48.9°C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in said inoculated mixture, the improvement comprising said lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50% Lactobacillus acidophilus, balance Lactobacillus bulgaricus and Strepto-coccus thermophilus in approximately equal proportions.
(32.2 to 48.9°C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in said inoculated mixture, the improvement comprising said lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50% Lactobacillus acidophilus, balance Lactobacillus bulgaricus and Strepto-coccus thermophilus in approximately equal proportions.
26. In a method for making a less than about 0.2% by weight fat and low calorie yogurt product containing fruit in an amount up to about 20% by weight of the yogurt pro-duct and 17 to 20% by weight total solids, including the steps of admixing low fat content pasteurized milk, stabil-izers and non-heat modified nonfat dry milk solids, heating said mixture to a temperature in the range from about 190 to 195°F (87.7 to 90.6°C), homogenizing said mixture at pressures in the range 500 to 5000 psig (35.15 to 351.5 kg/cm ), cooling said homogenized mixture to a temperature of about 90 to 120°F (32.2 to 48.9°C), inoculating said cooled homogenized mixture with a lactic acid producing bacterial yogurt culture mixture, maintaining said inocu-lated mixture at a temperature of about 90 to 120°F (32.2 to 48.9°C) for a time sufficient to produce a pH in the range of about 3.8 to 4.8 and to form an acceptable taste and texture in said inoculated mixture and combining said inoculated mixture with low calorie fruit preserves either before or after said maintaining step, the improvement comprising said lactic acid producing bacterial yogurt culture mixture consisting essentially of, by weight, 30-50% Lactobacillus acidophilus, balance Lactobacillus bulgaricus and Streptococcus thermophilus in approximately equal proportions.
27. A method, as claimed in claims 25 or 26, wherein said culture mixture consists essentially of 40% Lacto-bacillus acidophilus, 30% Lactobacillus bulgaricus and 30%
Streptococcus thermophilus.
Streptococcus thermophilus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000438805A CA1258400A (en) | 1983-10-12 | 1983-10-12 | Low calorie, low fat fruit-containing yogurt product and method for making same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000438805A CA1258400A (en) | 1983-10-12 | 1983-10-12 | Low calorie, low fat fruit-containing yogurt product and method for making same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1258400A true CA1258400A (en) | 1989-08-15 |
Family
ID=4126261
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000438805A Expired CA1258400A (en) | 1983-10-12 | 1983-10-12 | Low calorie, low fat fruit-containing yogurt product and method for making same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1258400A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110973259A (en) * | 2019-12-19 | 2020-04-10 | 成都师范学院 | Production process of large cherry yoghourt |
-
1983
- 1983-10-12 CA CA000438805A patent/CA1258400A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110973259A (en) * | 2019-12-19 | 2020-04-10 | 成都师范学院 | Production process of large cherry yoghourt |
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