FI75087C - Process for producing a microbiologically stable ice cream product. - Google Patents

Description

75087

Method for making a microbiologically stable ice cream product

Divided by application 780232 5

The invention relates to a process for the preparation of a microbiologically stable ice cream product which is substantially non-crystalline at freezing temperatures, spoonable at freezing temperatures of about -12 ° C and having a water activity of about 0.8 to 0.9.

In semi-moist food products, such as the ice cream product according to the invention, the principle is to reduce the amount of water available for microbial growth in the diet.

15 The water activity of a food product is defined as the quotient: the partial pressure of the water in the food product divided by the water saturation pressure at the temperature of the food product.

Early application in the water activity control technique was directed to animal feed. For example, U.S. Patent No. 3,202,514 discloses an animal feed having 15-30% moisture and 15-35% water-soluble solids, primarily sugar and proteinaceous meat. Subsequently, other intermediate Moisture content nutrient products were formed, such as egg products (U.S. Pat. No. 3,640,731), pancake batter (U.S. Patent No. 3,753,734), and whipped ingredients for confectionery use (U.S. Patent No. 3,958,033). The water content and water activity of these food products are reduced to as low a value as is practical to ensure their long-term stability without refrigeration. The main difficulty with these foods is that their low moisture content can impair their taste, tissue structure and mouthfeel. As a result, this technology has found its greatest commercial applicability in the pet-35 animal food market, where taste requirements are less stringent.

It is an object of the present invention to provide ice cream products which are normally maintained at freezer temperatures but which, when removed from the freezer, are easy to handle due to their retention and are microbiologically stable.

The invention thus relates to a process for the preparation of a microbiologically stable ice cream product, characterized in that the process comprises the steps of: (a) forming a mixture comprising about 2-16% fat, about 40-60% water, and sugar relative to water about 0.5 to 1.5: 1, wherein the total amount of fructose and dextrose is about 50 to 100% of the total sugar content, (b) the mixture is pasteurized, (c) the pasteurized mixture is homogenized, and (d) the product thus obtained is cooled.

The ice cream products of this invention are characterized by a high sugar content, preferably at least as much by weight as the water present, to provide microbiological stability. The sugars used have a low molecular weight, usually dextrose and fructose, which together account for at least about 75% of the total sugar content. The sweetness of sucrose is between the sweetness of fructose and destrose. Fruk-25, which is sweeter than dextrose, is preferred because it has a lower tendency to crystallize and cause hardness. It is preferred that the fats used include partially unsaturated fats that tend to provide better flow properties and nutritional benefits, although are less stable than saturated fats. The fat content is usually less than the water content to form a stable oil-in-water emulsion; the water content is preferably at least about 25% higher than the fat content.

ti 75087 The ice cream products of this invention are characterized by a water activity of about 0.8-0.9, and that the product remains spoonable at freezer temperatures. Although most semi-moist products consistently have a water activity of less than 0.85, some sacrifices in texture and taste may be required to implement this standard. Because ice cream products are maintained at freezer temperatures until they are used, a water activity of about 0.85 to 0.90 is suitable. Freezer temperatures, unless otherwise indicated, mean temperatures of about -21 to (-12) ° C, which is a common temperature range for freezers in homes and shops.

The spoonability property refers to the structure or flexibility of the product and the quality that the crude product can be eaten when it is at freezer temperature. By spoonability in this context is meant a property that gives a satisfactory reading in a standard penetrometer and / or flow test, which tests will be explained in detail later. The pourable products are more flowable 20 and are tested for flow properties.

The spoonable products of this invention gave a penetrometer reading of greater than about 3 mm and, while the products were also pourable, gave a flow rate of about 30 ml per minute or more during the first five minutes after removal from the freezer. These values are very significant compared to the normal frozen products currently on the market.

Throughout this application, all amounts are by weight unless otherwise indicated. In the examples, the amounts 30 are adjusted to base 100. Percentages are based on the weight of the entire composition, unless otherwise indicated.

The apparatus for measuring flow properties was made of stainless steel and consisted essentially of a stand 35.6 cm x 12 "x 30.5 cm and a pallet of the same size, which was adjustable vertically and angularly. The pallet was equipped with a bullseye level and a 75087 degree plate level. (protractor level); there was a wire support at the front to hold the sample container.

The following method was used to obtain flow values. Samples were filled into 600 ml scale cylinder-5 beads and frozen at -15 ° C for at least 24 h. Frozen (frozen) samples were removed from the freezer, immediately placed on a pallet in a horizontal position (0 °), and the effluent was collected in scale cylinders including volume at time intervals. Temperatures were monitored with a Honeywell record-10 device. Sample temperatures in the freezer ranged from -15.6 to -13.9 ° C over four weeks, but did not vary above 0.56 ° C over 8 hours; while the temperature in the freezer ranged from -15 to -9.4 ° C each time the door was opened. The room temperature ranged from about 1.12 ° C, with an average of 22.2 ° C, while the temperature of the samples in the original vessel rose from about -17 ° C to -10 ° C in 15 minutes after the sample was removed from the freezer.

Used penetrometrically and the equipment were standard-20 standards. The penetrometer is manufactured by Labline Instrument Co. Inc., Chicago, Illinois. The device measures the penetration of the tip of a hard rubber cone into a sample weighing 12 g, a height of 2.54 to 3.81 cm and a diameter in the base of 2.54 to 3.81 cm. The upside-down cone is supported by a freely sliding rod 25 weighing 48 g. For all measurements, the sample was placed in a freezer at -21.7 ° C and then removed from the freezer and tested immediately.

The products of this invention were freeze-thaw stable upon storage. The products were kept in a selection-30 store-type freezer unit, which alternately cooled the product and thawed the product six times a day. Under these conditions, the products remained acceptable and functional.

Il 5 75087 The ice cream was tested for volume and texture (granularity).

In a preferred method of making the ice cream product of this invention, all the ingredients are mixed in the desired proportions. Usually, most non-fatty ingredients are first dispersed in water. The ingredients are heated before or during mixing. For example, heating may begin during the mixing of the non-fat ingredients and then emulsifiers 10 and fats are added. The fat portion may also be preheated and then mixed in. The ingredients are pasteurized by holding them at an elevated temperature for several minutes, for example five minutes at 82.2 ° C.

The blended ingredients are then passed through a Meije-15 type homogenizer. Although homogenization can be accomplished in one step, it is accomplished in two steps to best achieve results.

The pressure is preferably maintained during the first stage with a minimum of about 13,800 kPa and a maximum of about 68,500 kPa, most preferably about 20,500 kPa, and during the second stage the pressure is maintained at about 3500 to 700 kPa, preferably about 3500 kPa. The mixture is usually maintained at a temperature of about 60-75 ° C during homogenization. The emulsion is cooled to about 0-25 ° C and passed through a blender to incorporate air or an inert gas such as nitrogen, carbon dioxide, nitric oxide or the like into the mixture. The mixer may be of conventional construction, such as a Hobart mixer or an Oakes continuous mixer, which allows the emulsion to be cooled to a temperature of about 5-15 ° C, preferably 10 ° C during whipping. The emulsion can be whipped over the original volume by about 100-500%, after which it is packaged and frozen.

By water-soluble substances is meant herein any additive that is substantially soluble in water at room temperature or at temperatures comparable to those used in the processing of food product 75087. Water-soluble non-sugar solids that may be used include certain inorganic salts, e.g., sodium chloride and potassium chloride; these are used in quantities that match 5 to the taste requirements. For example, diols and polyols, propylene glycol, sorbitol and glycerol, which have primarily an antifungal and / or structural function, can also be used.

The relative weight ratio of said water-soluble solids to the moisture content of the total product, during its manufacture and before packaging, determines the bacteriostatic effect. The amount of water-soluble solids can be varied, as can the amount of moisture originally incorporated into the product, within the above-mentioned limits. However, when these amounts are varied, the relative amount of water-soluble solids in the solution relative to water must be adjusted to provide the desired osmotic pressure. The weight of water-soluble solids available in the solution is preferably at least equal to the weight of moisture present, although in some cases it is possible that a smaller amount of water-soluble solids may provide some protection against microbiological degradation provided the osmotic pressure is similar. the size of. In any case, according to the present invention, the sugar constitutes the major part by weight of the water-soluble solids.

Semi-moist foods have a high sugar-30 content, which tends to promote non-enzymatic browning. This phenomenon is due to the complex reactions between the amino groups of proteins and the keto groups of sugars and is known as the Maillard reaction. This non-enzymatic tanning results in an undesirable darkening of the food product as well as side odors and flavors. These reactions can also reduce the nutritional value of food products. It is known, for example, that dextrose at lower concentrations than sucrose is able to produce an equivalent bacteriostatic effect, but dextrose is a reducing sucrose-5 di which tends to be subjected to an undesirable Maillard-type reaction. This reaction and other oxidative reactions progressively slow down as the temperature is lowered from room temperature to refrigerator temperature and further to freezer temperature.

By sugar is meant in this context any of a number of useful saccharides which are capable of increasing the osmotic pressure in aqueous solution and thus enhancing the required bacteriostatic effect. Useful sugars include monosaccharides, disaccharides and polysaccharides and their disintegration products; e.g. pentoses, including aldopentoses, methylpentoses, ketopentoses such as xylose and arabinose; deoxyaldose such as rhamnose, hexoses and reducing saccharides such as aldohexoses, glucose, galactose and mannose; ketohexoses such as fructose and sorbose; disaccharides such as lactose and maltose; non-reducible disaccharides such as sucrose and other polysaccharides such as destrinin and raffinose; and hydrolyzed starches containing oligosaccharides as ingredients. Typically, commercially available invert sugar mixtures containing dextrose and levulose as well as maltose and solid corn syrup are used. The sugars must be low molecular weight in order to be able to substantially increase the osmotic pressure of the sugar solution. Polyhydric alcohols may be used to replace some of the sugar used in this invention, e.g., about 0.5-5% of the compositions may be polyhydric alcohols such as glycerol.

Because the product of this invention is characterized by its considerable resistance to bacteria, but can act as a host for yeasts and molds, a sufficient amount of antifungal agent can be included in the food products of this invention to inhibit the growth of such organisms. Sorbate salts such as potassium 8,7878 sorbate and sorbic acid can be used either alone or in combination. Propylene glycol, which can be used alone or in combination with other humectants such as sorbitol to increase the softness of the product, can also act as an anti-5 mycotic agent. Other antifungal agents will be apparent to those skilled in the art. An antifungal agent is added of about 0.1% or more, depending on the antifungal agent and the product composition in question, although even smaller amounts, on the order of 50 ppm, may be used in the case of a few antifungals such as pimarsin. Antifungals that can generally be used include benzoic acid, sodium benzoates, propionic acid, sodium and calcium propionate, sorbic acid, potassium and calcium sorbate, propylene glycol, diethylpyrrole-15-carbonate, and menadione disodium bisulfite.

Other ingredients known to those skilled in the art may also be used to impart characteristic effects to the compositions of the present invention. Typical of such ingredients are perfumes and flavors, colors, Vita-20 mines, minerals and the like. Suitable flavoring agents can be used to provide, for example, flavors and aromas of vanilla, chocolate, coffee, maple syrup, spices, mint, butter, caramel or fruit. In addition, certain polyols such as sorbitol and mannitol can be used to modify the feel of the mouth. Furthermore, other additives such as phosphates and the like can be used to provide their known effects. These different types of substances are described below.

Highly unsaturated fats include safflower oil, corn oil, soybean oil, cottonseed oil and sunflower oil, unsaturated fats in this context are those having a iodine value of at least about 50, including partially hydrogenated fats, and over about 100. These fats are recommended for dietary purposes, especially for those users with high plasma cholesterol levels associated with atherosclerosis.

Il 9 75087

Saturated fats include hydrogenated petroleum products from coconuts, cottonseed, corn, soybeans, nuts, olives, etc. Preferred fats have a melting point of 32.3-34.4 ° C, i.e. the melting point 5 should be below body temperature.

Emulsifiers are necessary ingredients for the compositions of the invention which contain fats and are oil-in-water emulsions. A wide variety of emulsifiers can be used in amounts of the same order of magnitude as the previously known oil-in-water emulsions, e.g. about 1-5%, preferably about 0.2-1.5%. They provide a stable emulsion formation and improve the rate and total amount of aeration obtained. Particularly suitable are mono-, di- or polyglycerides of fatty acids such as monostearin and monopalmitin; polyoxyethylene ethers of fatty esters of polyhydric alcohols, such as polyoxyethylene ethers of sorbitan monostearate (polysorbate 60) or polyoxyethylene ethers of sorbitan distearate; fatty esters of polyhydric alcohols such as sorbitan monostearate; mono- and diesters of glycols such as propylene glycol monostearate and propylene glycol monopalmitate, succinic acid = mono-glycerides; and esters of carboxylic acids such as lactic acids, citric acids and tartaric acids with mono-glycerides of fatty acids such as glycerol lactopalmitate and glycerol lactostearate. Fatty acids used in the manufacture of emulsifiers include those derived from beef, tallow, coconut, cottonseed, palm oil, walnut, soybean, and traan. Many emulsifier mixtures are used commercially and are readily available according to the prior art. For example, it may be desirable to provide a controlled hydrophilic-lipophilic balance (HLB) with, e.g., a lipophilic emulsifier such as glyceryl monostearate or sorbitan stearate in combination with a hydrophilic agent such as e.g.

35 with polysorbate.

10 75087

The emulsion compositions of the present invention include one or more stabilizers or hydrophilic colloids that improve the consistency and structure of the coatings and promote freeze-thaw stability.

These stabilizers are natural, e.g. vegetable gums or synthetic gums and may be e.g. carrageenan, guar gum, alginate, xanthan gum and the like or methylcellulose, carboxymethylcellulose, ethylcellulose, hydroxypropylmethylcellulose and mixtures of these. Typically, gum or a combination of gums is used as a carrier for sugar, e.g. dextrose. The amount of these stabilizers can be varied widely within the amounts required in prior art compositions, generally about 0-2%, preferably about 0.1-0.5%.

Protein concentrates and isolates are useful for improving the nutritional properties of a product and for promoting and maintaining whipped structure. Protein also helps in emulsification and gives flavor. Of the protein fiber concentrates with a high fiber content, mild soy flour, milk powder and dietary proteins are useful, generally in concentrations of about 0-10%, preferably about 0.3-3%. Alternatively, a protein such as potassium or calcium caseinate, which is conventional in whipped coatings, may be used, or a small portion thereof may be replaced by a protein hydrolyzate.

Many types of salts are used in the compositions of this invention for flavoring, including common table salt (sodium chloride), sodium or potassium phosphates, citrates, chlorides and the like, about 0-5%, preferably about 0.1-1%.

Antioxidants such as butylated hydroxytoluene, butylated hydroxyanisole, and tertiary butylhydroquinone may be used in minor amounts (e.g., Tenox 35 22 antioxidant).

Il 11 75087

Edible acids such as phosphoric, tartaric, maleic, citric, fumaric and hydrochloric acids may be suitably used to produce bitterness, to adjust the pH or to act as a preservative.

The following ingredients may be used: The fructose-dextrose syrup (Isosweet) used in this invention contains 29% water and 71% sugars (50% dextrose, 42% fructose, 1.5% maltose, 1.5% isomaltose and 5% higher saccharides). A syrup rich in fructose 10 and dextrose contains 23.5% water and the remainder is 55% fructose and 45% dextrose. Fructose concentrate is an aqueous syrup with 80% sugar, 90% of which is fructose and the rest dextrose.

The maize syrup used has a moisture content of 22.5% and a dextrose equivalent of 29.0% (8.4% dextrose, 14.6% maltose, 8.6% trisaccharides and 68.4% tetrasaccharides and higher saccharides) called Amaizo Lodex C Corn Syrup sells American Maize-Products Co., New York, New York.

The following example illustrates the invention.

20 Example

The ice cream product made according to the invention remains soft in the freezer so that it can be used immediately after removal from the freezer.

Ice cream products contain about 45-60% water, sugar 25 to water about 0.5-1: 1 and fat about 8-16%. The total amount of fructose and dextrose is about 75-100% of the total amount of sugar, preferably the amount of fructose is 65-100% of the total amount of sugar. Fat is butterfat.

In non-regulatory (where ingredients can be varied independently of administrative regulations) ice cream substitutes may have a water content of about 40 to 60%, a sugar to water ratio of about 0.5 to 1.5: 1, and a fat content of about 2. .16%. The total amount of fructose and dextrose is about 50 ... 100% of the total amount of sugar.

12 75087

The following is a suitable ice cream composition.

Ingredients Quantity 1) Whole milk 40.00 2) Fructose concentrate 26.88 5 3) Thick cream 24.62 4) Skimmed milk powder 7.00 5) Sucrose 0.70 6) Sodium and potassium alginate 0.30 7) Polysorbate 60 0.10 10 8) Sorbitan monostearate 0.10 9) Vanilla 0.30 The fructose concentrate used is an aqueous syrup with 80% sugar, of which 90% is fructose and the rest dextrose.

The product had a water content of 54.12%, a sugar content of 28.7% (including sugars in whole milk, cream and dried milk) and a fat content of 10.26% (milk and cream).

20 The procedure for making the product was as follows: put the cream and milk in a saucepan and start heating. When the temperature reaches 60 ° C, the emulsifiers (7 and 8) are added. With stirring, a premix of sucrose (5) and alginate (6) is added, followed by fructose concentrate (2) and dry milk (4). Stirring is continued at 71 ° C for five minutes. The product is homogenized in a first step at 20500 kPa and in a second step at 3600 kPa, followed by cooling. The product is beaten to an excess volume of 100% and removed at -5.6 ° C. This ice cream product was placed in a freezer at a temperature of about -17.8 to -12.2 ° C for 72 hours and throughout this time retained a structure suitable for use. The preservation of this spoonable structure also makes it possible to package the ice cream in a flexible compression package (e.g. Squiggle-Pak) in the form of a strip-35 for dispensing.

Il

Claims (3)

75087 A process for preparing a microbiologically stable ice cream product which is substantially non-crystalline at freezing temperatures, spoonable at freezing temperatures of about -12 ° C and having a water activity of about 0.8 to 0.9, characterized in that the process comprising the steps of: a) forming a mixture comprising about 2 to 16% fat, about 40 to 60% water, and sugar to about 0.5 to 1.5: 1 water, wherein the total amount of fructose and dextrose is about 50 to 100% of the total sugar content, b) the mixture is pasteurized, c) the pasteurized mixture is homogenized, and d) the product thus obtained is cooled. Process according to claim 1, characterized in that in step a) a mixture is formed comprising about 45 to 60% water, sugar in relation to water about 0.5 to 1: 1, and about 8 to 16% fat, wherein 20 fructose and the total amount of dextrose is about 75 to 100% of the total sugar content, and the amount of fructose is about 65 to 100% of the total sugar content. Process according to Claim 1, characterized in that in step a) a mixture is formed which comprises about 90% of fructose, calculated on the total sugar content.