WO2000030457A1

WO2000030457A1 - Enzymatic preparation of cereal base

Info

Publication number: WO2000030457A1
Application number: PCT/US1999/027389
Authority: WO
Inventors: Kenneth Lewen; Daniel Fletcher; Robin S. Dickmann; Guoshen Yang; James B. Holder; Lori A. Wilson; Michael R. Andrews; Keswara R. Vadlamani
Original assignee: Kellogg Company
Priority date: 1998-11-20
Filing date: 1999-11-18
Publication date: 2000-06-02
Also published as: WO2000030457A9; AU1736200A

Abstract

Oat-derived non-dairy base prepared by enzymatically digesting a slurry of oats with an enzyme that generates glucose from the oat starch.

Description

ENZYMATIC PREPARATION OF CERE AL BASE

FIELD OF THE INVENTION

The pi esent invention is dπected to pi oduction ofaceι eal base

ιng ahιgh beta-glucan content, foods and be\ ei ages including the base, and methods foi pi epaπng the cei eal base The cei eal base is pi epai ed digesting a cei eal substi ate that contains beta-glucan w ith an enz me oi enz me miλtui e that break down stai ch wherein the 1 esultmg enzyme oi enzyme mixtui e does not have substantial actπ ity to bi eak the beta- 1 ,4-glycosιdιc bonds found in fibei to pi oduce the cereal base The cereal base may then be furthei pιocessedto \ ιeld a concentιate oι a dry pioduct or may be dπectly incorpoiated with othei ingredients to \ ield the desπed final pioduct Piefeiably the ceieal substi ate is oats oi a derivative of oats

BACKGROUND AND SUMMARY OF THE INVENTION

Dietary fiber has many health benefits, and is

n to aid digestion, I educe serum cholesterol, and has been shown to reduce the risk of othei conditions and diseases, e g heart disease, diverticulitis, ulcers, and colon cancer (Burkitt et al Lancet 2 1408-141 1 , 1972) Reduction of total seium cholesteiol s very important, since hypei cholesteolemia is one of the three majoi πsk factois for lschemic heart disease and thei e is a sti ong positπ e con elation betw een blood cholesteiol le\ els and the πsk of heart disease Beta-glucan is a soluble fiber with a proven cholestei ol lowering effect Beta-glucan is commonly found in giams such as barley and oats, yeast cell walls, and other natural sources Certain grains, particulaily oats, have a naturally high beta-glucan content, making them an excellent souice of beta-glucan Thus, coronary heart disease (CHD) is a major public health concern in the United States and it accounts for moi e deaths than any othei disease or group of diseases Early management of πsk factors foi CHD is a major public health goal that can assist in reducing the occurrence of CHD Scientific evidence demonstrates that the addition of soluble fibei fiom certain foods to a diet that is low in saturated fat and cholesterol may help i educe the nsk of CHD The U S Foodand

Drug Administration has authoπzed the use of a health claim for foods that are high in oat bran and oatmeal and low in saturated fat and cholesterol The U S FDA concluded that a daily intake of not less than 40 g of oat bran or 60 g oatmeal (proudmg 3 g oi more per day of β- glucan soluble fiber) is associated with reduced risk of coronary heart disease. Trowell (Am. J of Clin. Nutr. 25: 464-465, 1972) reported that diets deficient in dietary fiber contribute to ischemic heart disease. A number of studies by several researchers (Anderson and Chen, Am. J. Clin. Nutr. 32: 346, 1979; Judd and Truswell, pp 23-39 in: Dietary Fiber Perspective A.R. Lees ed.; Van Horn et al., J. Am. Diet Assoc. 86: 759. 1986) have shown that the consumption of soluble fiber can lower serum cholesterol in humans. The U.S. FDA has stipulated guidelines for sources of β-glucan soluble fiber that meet the health claim requirement. Oat bran, rolled oats, and whole oat flour are three allowed sources of β-glucan soluble fiber. All three materials will meet the FDA health claim requirement, provided that the contents of β-glucan and total dietary fiber (TDF) of the raw material is at least 5.5% and 16% (dry weight basis (dwb)) respectively for oat bran, or at least 4 and 10%o (dwb) respectively for both rolled oats and whole oat flour. Food products prepared from the above qualifying whole oat sources and having 0.75g or more of β-glucan soluble fiber per reference serving amount may be labeled to indicate that the product may help reduce the risk of coronary heart disease. However, suitable beverages, and many other food products meeting this requirement are difficult to prepare because the insoluble fiber in the oats yields a gritty product.

Additionally, it is difficult to achieve the required β-glucan content in foods other than baked goods, or those having large reference serving sizes due to the relatively low concentration of β-glucan soluble fiber in oats relative to their starch content, resulting in a "pasty", or "starch- textured" product. Oats also have a distinct "oaty" aroma and flavor that is not compatible with many commonly consumed food products andthis aroma and flavor become distinctive at higher levels of oat content. Furthermore, oats have a high content of native lipase and oil that is susceptible to oxidative rancidity and this characteristic adversely affects the shelf-life of convenience foods prepared with high levels of oat. The protein component of oats can produce a bitter flavor and an undesirable opacity in certain foods such as beverages.

U.S. Patent No. 4,996,063 to Inglett discloses a method to prepare water-soluble dietary fiber compositions. The process involves treating an aqueous dispersion of a gelatinized, milled, oat substrate, e.g. oat flour, with a thermostable α-amylase under conditions which hydrolyze the oat substrate and yield soluble and insoluble fractions. The soluble fraction comprises soluble oat fibei and maltooligosaccharides, and the insoluble fiaction contains a high proportion of protein as well as insoluble fibei The enzyme is then inactivated, e g by passing the mixtuie thiough a steam injection cookei at a tempeiatuie of 140°C, oi by acidification The soluble fraction is then sepaiated fiom the insoluble fiaction by centπfugation, and the watei -soluble dietary fibei is lecovered fiom the soluble fraction, e g by lemoving the \\ atei This mateπal does not qualify to make the FDA health claim regarding the i eduction of coi onary heart disease because it is lacking in insoluble fibei

U S Patent No 4,377,602 to Coniad describes a hydi olyzed pi otein and starch pioduct prepared, in situ, by enzymatically hydiolyzmg piotem and starch pioducts fiom whole giam Whole giain is crushed in ordei to expose the endosperm and theieaftei the crushed giain is subjected to enzymatic treatment with an endopeptidase in an aqueous medium to tiansform water-insoluble proteins to watei -soluble protein products The watei -insoluble piotem pioducts ai e then filtei ed and recovei ed The remaining crushed gi am is then treated w ith (α-amylase in an aqueous medium followed sequentially by an amyloglucosidase, so as to tiansform substantially all of the watei -insoluble staich fi actions m the giam to glucose This mateπal also does not qualify to make the FDA health claim regai ding the l eduction of coi onary heart disease because it is lacking m insoluble fibei

In Food Technology, 45 (6) 104 (1991) Inglett et al describe a pioduct, Oatπm, a maltodexti in made fi om oats that is i eported to pi ovide a high beta-glucan content and is used as a fat leplacei Oatπm is reported to have a seium cholesteiol-loweπng effect and is piepaied by converting oat staich to maltodextπn with a thermo-stable α-amylase (U S Patent No 4, 996 063)

To date, Oatπm has not qualified to make the FDA health claim regaiding reduction of coronary heart disease because it is lacking m insoluble dietary fiber European PatentNo 231 729 B 1 discloses api ocess foi manufactuπng foodstuffs starting from whole floui of a starch containing cereal grain The whole gi am floui may be dei lved fi om oats and is then suspended in water containing 40-150 ppm calcium ions The pi ocess described in this Eui opean patent includes the sequential treatment of gi am flour first with α-amylase and then with beta-amylase The resultant liquid can be used to make beveiages One embodiment in EP 729 is directed to a process pre-treating a barley-based flour with beta-glucanase to reduce viscosity prior to treatment with alpha-amylase. The treatment with beta-glucanase will alter the stmcture of β-glucan and destroys its intended physiological properties, rendering the material unqualified for the U.S. FDA health claim. U.S. Patent No. 5,686,123 to Lindahl et al. discloses a method to prepare an oat based cereal suspension containing intact beta-glucans by suspending diy- or wet-ground rolled oats or otherwise heat-and water-treated oats, optionally centrifuging or decanting the suspension to remove coarse fiber particles. The suspension depleted in fiber is then treated first with a beta- amylase and then subsequently with an alpha-amylase, each enzyme step being performed to achieve a specific endpoint determined by viscosity. The suspension is then homogenized and subjected to an ultra high temperature (UHT) treatment to inactivate the added enzymes and obtain a sterile product. This material do not qualify to make the FDA health claim regarding the reduction of coronary heart disease because it is lacking in insoluble fiber.

Enzymatic treatment of cereal grains has also been used to make fat substitutes, such as described in U.S. Patent No. 5,912,031 to Fitchett et al. Fitchett et al. describe preparation of a fatreplacerby enzymatic digestion of aground cereal with alpha-amylase by forming an aqueous sluιτy of ground cereal, the sluπy having a dry solids content of 10 to 50 weight percent; enzymatically digesting the slurry at 60-95° C with an alpha-amylase enzyme capable of being deactivated by temperatures below 100 °C, whereby the enzymatic digestion is effected without any significant protein degredation, and thermally deactivating the alpha-amylase enzyme. The products of the process are reported to be useful as fat replacers in a wide variety of foods, including baked goods, dairy products, and meat products.

Despite these different approaches, it remains difficult to provide a beverage or food having a relatively high beta-glucan content while maintaining the total dietary fiber content intact, without strong "oaty" taste or smell. Also, the products produced in prior art do not qualify for U.S. FDA health claims as the insoluble fiber is removed during these processes.

Thus, there is a real and unsatisfied need in the art for an improved method to produce a concentrated form of wholesome cereal grain product rich in beta-glucan as well as total dietaiy fiber. These objects are achieved by the present invention, which relates in part to a cereal base having on a diy-weight basis (dwb), a beta-glucan content of from about 5 to 25%, and preferably a total dietary fiber content of from about 10% to 50% It is prefeired that the cereal base and final products prepared therefrom qualify to make the coronary heart disease health claim according to the proscriptions of the U S Food and Drug Administration In prefen-ed embodiments, the invention is directed to a method of preparing an oat base by preparing an aqueous sluπy containing 5 to 45% oat substrate on a diy weight basis and treating the sluπy with an enzyme, e g , alpha-amylase, having substantially no beta-glucanase activity to hydrolyze the starch The oat substrate may be completely or partially gelatinized before or after introduction of the enzyme Gelatinization may be accomplished by, e g , heating the slurry to a temperature sufficient to gelatinize at least a portion of the starch The enzyme treatment continues until the desired endpoint is reached, andthe enzyme is then inactivated, e.g , by heating or adjusting the pH of the sluπy The resulting product is a cereal base rich in beta- glucan which can be directly incorporated with other ingredients to form the final edible product, typically a food or beverage Any enzymes that are capable of breaking down starch to dextrins, maltose, glucose, or any combination of these final products can be used The enzymes are preferably free or substantially free of enzymes that break down beta-glucan, such as beta-glucanase Preferred enzymes include thermo-stable alpha-amylases stable at temperatures greater than 100 ° C, moderately thermo-stable alpha-amylase, heat-labile alpha-amylase, isoamylases and amyloglucosidases

The resultant cereal base may be further processed, e g , by dehydrated sufficiently to yield a liquid concentrate or a solid

The invention is described in further detail below

DETAILED DESCRIPTION OF THE INVENTION

To prepare the cereal base of the present invention, referred to as "oat base" hereinafter, an aqueous slurry of oat substrate is prepared by admixing an aqueous fluid or an emulsion having an aqueous component, e g water or milk, with an oat substrate containing beta-glucan The oat substrate may be, e g , whole gra oats, rolled oats, oat bi an, oat floui or the like Othei gram substrates having a beta glucan content, such as bailey, may also be used, but oat substi ates aie prefeπed It is pieferred that the oat souice is a qualifying oat souice m oidei to make the U S FDA appi oved health claim regarding reduction of the risk of coi onaiy heart disease, oi a coπespondmg claim in a given country Piefeiably the oat source is an oat mateπal that has been pre-heat tieated in oidei to inactivate the native enzymes, foi e g hpase A piefeπed oat substi ate is milled to an aveiage particle size of less than 500 micions Piefeiably the aveiage particle size ranges between 20 to 200 microns

A particulaily prefeπed oat substi ate is an oat substi ate that is subjected to one oi moie techniques that will sepaiate the oat fiaction rich in soluble and insoluble fibei fiom the oat fi action that is pooi in soluble and insoluble fiber, yielding a fraction that is l elatively highei in beta-glucan content Suitable techniques for preparing an oat substi ate fiaction having a l elatively high beta-glucan content include, but are not limited to sieving and air classification The amount of beta-glucan in such fiactionated oats typically langes fiom 5 to 25% by weight. and piefeiably fiom 15 to 20% by weight beta glucan It will be recognized that variations outside these i anges will occui due to many factors, including the starting content of beta-glucan in the starting oat substrate It is contemplated that genetically engmeei ed oats or cereal grains may be developed that will have a higher content of beta-glucan than m presently available souices, and it is anticipated that these will be suitable for use withm the scope of the present invention

A particularly piefeπed oat substrate is oat bran that has been milled to an aveiage particle size below 500 microns, and has been fractionated via an classification to remove the less dense particles and increase the percent soluble and insoluble fibei in the oat bran The final particle for the oat substrate depends on the final use For example, beverages require a relatively small particle size, e g less than 75 microns Baked goods typically do not have a particle size limitation, and oat bian that has been air classified without additional milling may be used

The sluπy prefei ably contains 1 to 45 wt % oat substrate, preferably 15 to 25 wt % The substi ate may be added all at once pnor to addition of the enzyme, or may be added stepwise, allowing foi partial oi complete enzyme digestion pπoi to incorporation of additional portions Aftei the sluπy is pi epaied it is tieated with the enzyme to hydi olyze the stai ch in the oat substrate The oat substi ate may be gelatinized eithei pπoi to oi aftei the addition of the enzyme e g , by laising the tempeiature of the sluπy foi a sufficient penod of time to gelatinize the staiches Typically, a temperature above 65°C is maintained, piefeiably a tempeiatuie of 85 to

90°C foi about 5 to 10 minutes If gelatimzation is conducted pπoi to addition of the enzyme the sluπy may be cooled befoie the enzyme is added

Any enzyme oi mixture of enzymes capable of breaking down stai ch typically to dextπns maltose, oi glucose and that does not exhibit substantial activity, and piefeiably exhibits no activity foi the bieak g of beta-l ,4-glycosιdιc bonds found m fibei can be used This is important because seveial available enzymes contain othei enzymes, which can be chai acteπzed as impuiities, that exhibit such activity and would hydi olyze beta-glucan, deci easing the beta- glucan content of the cei eal base An alternate method is to heat use thermostable enzymes that may have activity foi bieakmg down the beta-l ,4-glycosιdιc bonds, but the slurry oi liquid is heated to a high enough temperatui e to inactivate the enzymes or contaminants lesponsible foi the degiadation of the fibei , but not to inactivate the desn ed enzyme oi enzymes The pieferred enzymes include thermo-stable alpha-amylases (typically stable at tempeiatuies gieatei than 65°C), heat-labile alpha-amylase, beta-amylase, isoamylases and amyloglucosidases It is anticipated that heat-stable amyloglucosidases will become available m the futuie and this enzyme will be piefeπed foi bieakmg down starch to glucose with the use of a single enzyme and a gelatimzation step

A non-limiting list of enzymes which may be used in accordance with the piesent invention include G-Zyme® G995E and G990 (Enzyme Bio-systems Ltd ). Termamyl 120L Type L (Novo Noi disk) , Maltogenase 4000L (Novo Noi disk), Canalpha 600,00L and 60P (Quest International), Fungamyl 800L (Novo Nordisk), AMG 300L (Novo Nordisk), and othei variations of these enzymes

G-zyme G995-E is also a thermostable alpha-amylase denved from Bacillus stearothermoplnlus G995-E is most active between pH 5 0 and 7 0 and at temperatures as high as 108°C While G-zyme G990 is a glucoamylase produced extiacellularly from Aspergilhis niger. G990 can hydrolyze both the alpha- 1 ,6 and alpha- 1,4 glucosidic bonds of starch

Termamyl 120L, Type L, is a thermostable alpha-amylase produced by a genetically modified Bacillus lichenifonnis . This enzyme is an endoamylase, which randomly hydrolyzes 1,4-alpha-glucosidic linkages in amylose and amylopectin of starch, and rapidly converts the starch to soluble dextrins and oligosaccharides.

A particularly preferred alpha-amylase is Maltogenase 4000LO commercially available from Novo Nordisk. This enzyme is a moderately heat-stable thermostable maltogenic alpha- amylase derived from Bacillus stearothermophilus expressed in and produced by a genetically modified strain of Bacillus suhtilis. The optimal activity level for Maltogenase is between 55 and 75°C and may be inactivated at 95°C for 15 minutes.

Another prefeired enzyme is Canalpha 60P (powder) and 6OO,O00L (liquid) from Quest

International are the same enzyme but in different forms and strengths This enzyme is a thermostable bacterial alpha-amylase derived from fermentation with aselectedstrain of Bacillus suhtilis. The optimal activity level is between about 65 and 85°C and may be inactivated at 95 °C for 15 minutes.

Fungamyl 120L is a fungal alpha-amylase obtained from a selected strain of Aspergillus oryzae. This enzyme hydrolyzes the alpha-1 ,4 glucosidic linkages of starch and a prolonged reaction results in the formation of large amounts of maltose.

AMG is an exo-l ,4-alpha-D-glucosidase referred to as a glucoamylase or amyloglucosidase AMG is obtained from a selected strain of Aspergillus niger by submerged fermentation. This enzyme hydrolyzes both the 1 ,4 and 1 ,6-alpha linkages in starch, and removes glucose units in a stepwise manner from the non-reducing end of the starch molecule.

Other enzymes derived from these and other sources are expected to be acceptable for use in accordance with the present invention, and the aforementioned enzymes are mentioned solely as prefeired enzymes.

The amount of enzyme added and the reaction time for the enzyme is determined, inter alia, by the desired texture of the final product and the percentage of grain solids, e.g. oat bran or barley flour, in the mixture.

Optionally, a suitable calcium source may be added to stabilize the enzyme. Typically. from about 20 to 50 ppm Ca+÷ is added and the amount is dependent on the processing conditions and the type and amount of enzyme used. Another option, is that sucrose in amounts of from 1 to 10% by weight can be added to the enzyme prior to addition to the heated water or sluπy. The sucrose can be diy mixed with the enzyme or added to a liquid enzyme. After preparation of the slurry, the enzyme digestion of the starch is continued until the desired products and viscosity are obtained. Preferably, the temperature is maintained or steadily raised to between 55 and 85 °C for about an 1 hour and usually less than 25 minutes The temperature is then raised for a sufficient length of time to gelatinize the starch, a temperature above 65°C is maintained, preferably a temperature of 85 to 90°C for about 5 to 10 minutes. These lengths and temperatures may be less than 1 minute and greater than 6 hours depending on the conditions of the slurry and enzyme used

After gelatinization, the slurry may optionally be cooled for the addition of the same enzyme(s) or different enzyme be added, and digestion may then be continued to reach the desired endpoint. Preferably, the enzymes are inactivated by an appropriate method which depends upon the final use of the product. Methods of enzyme deactivation include heating, pH adjustment, and spray drying. For the prefeπ'ed enzymes, temperatures in excess of95°C for 10 minutes are generally sufficient to inactivate the enzymes. High temperature and short time inactivation can be achieved by several methods including jet cooking, preferably at temperatures between 138 and 176°C and ultra-high temperature (UHT) processing, preferably at 137 to 144°C for 2 to 10 seconds.

If the product is to be dried, any number of drying techniques can be used, but it is preferred to use a technique that will also inactivate the enzymes, such as spray drying. It is preferred that the dried cereal base is in a powder form. In a preferred embodiment, the resulting liquid cereal base is subjected to high shear forces by using equipment such as a homogenizer, microfluidizer¹ (MFIC Coiporation), and jet cooker. Homogenization is earned out under suitable conditions, preferably at temperature of 55 to 70°C at pressures of 500/3500 to 1000/5000 psi.

The resultant oat base will have a minimum total dietary fiber content of between 10 and 30% (dwb), and a beta-glucan content of at least 4%. preferably at least 5%.

In a preferred embodiment, the oat base is prepared by heating water to a temperature of from 70 to 95°C, adding an enzymatically effective amount of a thermostable alpha-amylase, adding from about 10 to about 30% by weight of a grain containing beta-glucan, e.g. oat bran or barley flour, cooling, adding other drink ingredients such as fruit and flavorants, preheating the mixture to a temperature above 65°C, and subjecting the mixture to an ultra high temperature step at a temperature of from 138 to 176°C, and optionally homogenizing the mixture to the desired consistency.

An important feature of the processes of the present invention is that removal of the insoluble solids is not required as with prior art processes.

Preferably, the product is prepared as a dry solid by removing the water from the enzyme digested oat-liquid to yield a dry solid. This may be accomplished, e.g., by spray drying, drum drying or evaporation.

The oat base can be used in either liquid or solid form for use in a variety of food products, including, but not limited to baked goods, cereals, and preferably beverages.

Preferably the resultant food will qualify under FDA rules for a cholesterol lowering claim and therefore, whether the product is used as a liquid or solid, the product is preferred to contain 0.75 g of beta-glucan per RACC serving.

To prepare final products, the oat base is mixed with other food ingredients such as flavors, colorants and the like and are finally prepared according to art-known techniques. For beverages, it is preferred to directly use the enzymatically treated sluπy as the oat base.

The present invention also relates to treating hypercholesterolemia in a patient by administering a sufficient amount of the oat base or a food containing the oat base. Treatment includes aiding in the control of, or alleviating the effects associated with hypercholesterolemia, including reducing the risks or effects of coronary artery disease.

The following examples are illustrative of the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Example 1

Fine Oat Bian (25 7 lbs, 6 7% β-glucan and 15 8% TDF (dwb)) w as added to watei (94 3 lbs, 130°F) containing calcium ( 100 ppm pei giam of staich) and Fungam\ l ( 15unιts^;g starch) and Amyloglucosidase (5 units/g starch) such that the solids content was 20%. and pH of sluπy 6 3 The fine oat bian has a mean particle size of 48 μm with 50% of mateπal <30 μm and 90% <1 18 μm This oat material was added to w atei that contained staich hydiolyzing enzymes at a constant rate (1/7"¹ every 5 minutes ovei 30 mm peπod) such that, at no point of time, the viscosity ofthe slurry was excessively high The slum w as maintained at a temperature of 131 °F and the hydiolysis continued foi anothei 20 minutes (total time, 1 houi) and the viscosity of lesultant sluπy was between 6 and 360 cp The slum was then heated to about 185°F to gelatinize the partially hydrolyzed oat starch The viscosity ofthe resultant liquid was between 75 and 6,000 cp dunng gelatimzation The slurry was then cooled to about 131 ° F, and a second batch ofthe same enzymes (m the same ratios) wei e added to the sluπy This enzyme treatment was continued foi ~30 minutes at 131 °F until the viscosity of the liquid leached about 100 to 125 cp This twice-enzyme ti eated slurry was then heated to 170 °F for 20 minutes to inactivate the enzymes The sluπy was then homogenized twice by passing through a Gauhn Homogemzei at 1 ,000/5,000 psi, and spray dπed with conventional equipment (inlet 365°F. outlet 203 ° F) to yield a powdery oat based substance

Example 2

In this example, Fine Oat Bran (1 1 1 lbs, 6 7% β-glucan and 15 8% TDF (dwb)) was added to watei (88 9 lbs, 130°F) containing 100 ppm calcium such that the solids content was 10% and pH ofthe slurry 6 3 The slurry was heated to about 185°F to gelatinize the starch The viscosity of the l esultant liquid was between 300 and 105,000 cp during gelatimzation The slurry was then cooled to 131 °F and Fungamyl (30 units/g of starch) and Amyloglucosidase ( 10 units/g of starch) were added to the sluπy The enzyme hydrolysis was continued foi ~40 minutes at 131 °F until the viscosity of the liquid reached about 25 - 40 cp Then, the tempeiature of sluπy was brought up to 170°F and held for 20-30 minutes to inactiv ate the enzymes The sluπy was homogenized twice at 500/3 000 psi and spray dπed (inlet 365°F and outlet 203 °F) to yield a powdery oat-based substance

Example 3

Concentiated Oat Bian (26 7 lbs, 14 0% β-glucan and 31 8% TDF (dwb)) was added to watei (93 3 lbs, 130°F) containing 100 ppm calcium and Amyloglucosidase (40 units/ g of starch) such that the solids content was 20% and pH ofthe slurry 6 3 The mean particle size of concentiated oat bian was 80 μm with 50% of material < 83 μm and 90% < 180 μm The oat matenal was added to water that contained staich hydrolyzmg enzyme at a constant late ( 1/7* every 5 minutes ovei 30 mm peπod) such that, at no point of time the viscosity ofthe slurry was excessively high It was obsei ved that the oat mateπals that contain high amounts of β-glucan build excessively high viscosities and is important to keep the viscosity down foi ease of processing The hydrolysis was continued foi another 20 minutes and the viscosity of the lesultant liquid was between 10 and 2600 cp The slurry was heated to about 185°F to gelatinize the staich and the viscosity was between 250 and 6,000 cp dunng gelatimzation process The sluπy was then cooled to 131 ° F and Amyloglucosidase (40 units/ g of stai ch) vvei e added to the sluπy and the hydi olysis continued foi - 30 minutes at 131 °F until the viscosity of the liquid leached about 125 - 150 cp Then, the temperature of sluπy was bi ought up to 170 °F and held foi 30 minutes to inactivate the enzymes The sluny was homogenized twice at 500/3 000 psi and spray dπed (inlet 356°F and outlet 203 °F) to yield a powdery oat-based substance

Example 4

In this example, Fine Whole Oat Flour (4 6% β-glucan and 15 7% TDF (dwb)) at 20% solids was used as a starting raw mateπal and processed exactly as described m Example 1 The mean particle size of raw whole oat flour was 26 μm with 50% of matenal < 17 μm and 90%> < 60 μm The chemical characteristics and particle size distribution of finished spiay-dπed oat materials produced in Examples 1 through 4 are given in Table I The results in the table demonstrate that there was no or very little loss of beta-glucan and total dietary fiber content m the finished material

Table I.

Moisture β-glucan TDF Sugar Profile Particle Size

Distribution

(Reconstituted)

Sam (%db) (%db) Glucose F Maltose Sucrose Mean 50% 90% pie ruetose (%) ( (%) (%) (urn) (urn) (κrιι)

%)

Fine 3 88 6 56 15 81 40 60 0 3 51 0 71 37 22 96

Oat Bran 33

Con 4 55 14 56 ₂7 66 27 10 0 0 00 1 10 49 28 129 c Oat Bran 47

Fine 3 68 4 05 16 80 46 00 0 1 82 0 44 3₂ 22 77

Oat Flour 45

Example 5

In this example, Fine Oat Bran (333.3 g, 6 7% β-glucan and 15.8% TDF (dwb)) was added to water (1 166 7 g, 180^CF) containing calcium (100 ppm per gram of starch) and

Termamyl (diluted 1 ml in 100 with water, 30 units/g starch) such that the solids content was

20% and pH of slurry 6.3. The fine oat bran has a mean particle size of 48 μm with 50% of material < 30 μm and 90% < 118 μm. This oat material was added to water that contained starch hydrolyzing enzymes at a constant rate ( l/3^rd every 15 minutes over 45 min period) such that, at no point of time, the viscosity ofthe slurry was excessively high The slurry was maintained at a temperature of 180°F and the hydrolysis continued for another 15 minutes (total time, 1 hour) and the viscosity of resultant slurry was between 6 and 3200 cp The sluny was then cooled to about 131 °F, and Amyloglucosidase (10 units/g starch) was added to the sluπy. This enzyme treatment was continued for 1 h at 131 °F until the viscosity ofthe liquid reached -300 cp. This twice-enzyme treated slurry was adjusted to pH 4 with 1 N HCI and then heated to 185 °F for 20 minutes to inactivate the enzymes. The slurry was then homogenized twice by passing through a Gaulin Homogenizer at 1 ,000/5,000 psi, cooled and the pH adjusted to 6 3 with 1 N NaOH to yield a liquid oat base. Example 6

An orange-cream beverage were prepared from: 800-850 g of water, 20-75 g of oat-base made from Example 1 using 4.62 g of high fructose corn syrup, 37 g of orange juice concentrate, 17 g of sugar, 2 g of gum, 2 g of citric acid and colors and flavors. The ingredients were mixed together, homogenized at 500/2,500 psi, bottled, and batch pasteurized by holding 1 minute at 180°F, and cooled immediately to 60 °F. The beverages had a pH of 3.8, brix (soluble sugar solids) of 12-14° and viscosity of 30-40 cp. These orange-cream beverages have a good taste, pleasant aroma, no grittiness, and provide 0.75 g of β-glucan per 8 fl.oz serving and qualify for U. S. FDA coronary heart disease health claim.

Example 7

In this example, 3085 grams of skim milk, 2% milk or whole milk (prefer 2% milk) is heated to 190F. 0.8 gram Canalpha 60P dispersed in 100 grams granulated sugar was added to the milk. Medium size oat bran (4.8% b-glucan from ConAgra) was added to the milk/enzyme mixture, and the mixture was vigorously stin-ed for about 5 min to gelatinize oat starch by heat and partially liquefy the gelatinized oat starch by the enzymatic reaction. The mixture than was heated to boil for 5 min to denature the residual enzymatic activity. The resultant slurry was homogenized immediately through a high speed homogenizer to rupture the cell wall materials in oat bran. After homogenizing, the material was extruded though a masticating juicer equipped with 40 mesh screen three times with slow speed to separate out the insoluble coarse fiber fraction. The final product (filters through 40 mesh) had a pleasant sweet oat taste and creamy smooth texture like chocolate moose. The b-glucan content, pH and viscosity ofthe product are 0.5-0.9 %, 6.3, and 10,000-35,000cp respectively.

Example 8

In this example, 44.5 pounds of whole grain oat flour (3.2% b-glucan) was mixed into 150 pounds of hot water (150-160F) using a tri-blender. The mixture then was transferred to a steam-jacketed kettle and heat to a temperature of 190-degree F. At this point. 8.17grams of Canalpha 60P dispersed in 300 grams of granulated sugar was added. The mixture was held at

190F for 30 min to gelatinize and partially liquefy oat starch in oat bran. The mixture was transfeired to a mix tank and cooled to 100F, and 12.13 pounds ofmilk solid, 30.13 pounds of sugar, and 0.26 pounds of vitamins/minerals mix, 13.84 pounds of peach puree, and 0.36 pounds of peach flavor, 1.8 pounds of canola oil, and 0.254 pounds of lecithin, were added finally. The final mixture was preheated to 165F in plant heat exchanger and UHT treated (290 for 4-10 seconds) in Sterilab 300 VTIS system. After UHT treatment, the product was homogenized at 160F (2500PSI in the 1 st stage and 500 PSI for the second stage). The product was cooled down to 40-50F and stored in Steritank before aseptic packaging. The final product was packed in 250 ml Tetra-Pak container. The product has a smooth texture and fruity clean oat taste. The b-glucan content of the final product was about 0.3-0.4%>. One serving of above product provides 25%

RDI of typical vitamins andminerals and 0.75-1.00 grams of b-glucan. The final shelf stable, low acid oat and milk based drink meet FDA health claim.

Other facets of the invention will be clear to the skilled artisan, and need not be set out here. The terms and expression which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expression of excluding any equivalents of the features shown and described or portions thereof, it being recognized that various modifications are possible within the scope ofthe invention.

Claims

We claim:

1.

A process for preparing an oat-derived base comprising: preparing an oat based sluπy having a solids content of between 5 and 45 % oat substrate by weight, said oat substrate containing beta-glucan and oat starches; heating the slurry to gelatinize at least a portion of the oat starches; adding an effective amount of at least an enzyme that has substantially no beta- glucanase activity and digesting to the desired endpoint; and inactivating said enzyme to yield the liquid oat base.

2. The process of claim 1 , wherein said enzyme is selected from the group consisting of a thermostable alpha-amylase, a heat-labile alpha-amylase, and an amyloglucosidase.

3. The process of claim 1 , wherein prior to gelatinization the oat slurry is treated with an enzymatically effective amount of said enzyme.

4. The process of claim 1 , further comprising removing water to yield an oat-based solid.

5. The process of claim 1 , wherein prior to gelatinization, at least one enzyme selected from the group consisting of a thermostable alpha-amylase, a heat-labile alpha-amylase, and an amyloglucosidase is added to the sluπy and the slurry is enzymatically digested at a temperature of from 1 10 to about 140°F and the resultant sluny had a viscosity between 10 to 2600 cp.

6. The process of claim 1 , wherein the aqueous sluπy is prepared with milk or skim milk.

7. The oat base prepared by the process of claim 1.

8. The oat base prepared by the process of claim 2.

9. The oat base prepared by the process of claim 3.

10. The oat base prepared by the process of claim 4.

1 1. The oat base prepared by the process of claim 5.

12. The oat base prepared by the process of claim 6.