WO2001062099A1

WO2001062099A1 - Edible product with live and active probiotics

Info

Publication number: WO2001062099A1
Application number: PCT/US2001/005509
Authority: WO
Inventors: Martin J. Rudolph; Jeffrey H. Worthington; Jeanne M. Bolger
Original assignee: Arthur D. Little, Inc.
Priority date: 2000-02-25
Filing date: 2001-02-22
Publication date: 2001-08-30
Also published as: AU2001238589A1

Abstract

The shelf-stabilized probiotic food product contains active culture probiotic microorganisms, a dairy or soy milk product, and one or more low-moisture food ingredients. The mixture is aerated with a gas, frozen, molded or extruded into a desired shape, and then freeze-dried. The food product is preferably formed in the shape of a bar, cookie or nugget.

Description

EDIBLE PRODUCT WITH LIVE AND ACTIVE PROBIOTICS

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the priority of U.S.

Provisional Application No. 60/234,429, filed September 21, 2000; of U.S. Provisional Application No. 60/201,107, filed May 2, 2000; and of U.S. Provisional Application No. 60/185,201, filed February 25, 2000, the whole of which are hereby incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR

DEVELOPMENT N/A

BACKGROUND OF THE INVENTION

The beneficial properties on human health of certain

"probiotic bacteria" are well known. For example, certain

Lactobacillus strains reduce diarrhea caused by lactose intolerance, rotavirus infections (causing infantile diarrhea) , or antibiotic therapy (caused by C. difficile) . Other probiotic bacteria attack the microbes that cause illnesses such as food poisoning (caused by E. coli) , ulcers and gastritis (caused by H. pylori) , boost the number of immune cells in the body, and reduce cancer risk.

Various products have been prepared for human consumption to provide these organisms in a palatable form. Some examples include beverages containing active lactobacilli; capsules and tablets containing lyophilized lactobacilli (U.S. Patent No. 4,396,631); instant, dry powdered yogurt that is reconstituted with milk (U.S. Patent Nos. 5,145,698 and 3,897,307); ice cream with a coating containing lactic acid bacteria (U.S. Patent No. 6,022,568); lyophilized kefir yogurt (U.S. Patent Nos. 4,702,923 and 4,797,290); low fat, thin bodied yogurt product (U.S. Patent No. 4,837,036); chocolate shell containing a fermented filling with live lactic acid bacteria (U.S. Patent No. 5,573,793); and soybean milk yogurt (U.S. Patent No. 4,066,792). Yet, there is still a need for a good tasting probiotic food product that is in ready-to-eat, shelf-stable form.

SUMMARY OF THE INVENTION The shelf-stabilized probiotic food product of the invention, preferably formed into a predetermined geometric shape such as a bar, cookie or nugget, includes one or more active culture probiotic microorganisms, in the form of a cultured dairy or soy milk product, and one or more low moisture food ingredients in a proportion of, e.g., from 25:1 to 1:2 (wt:wt). The food product of the invention is freeze-dried (lyophilized) , contains at least 10⁶ cfu of live and active cultures per gram of product and, preferably, further includes one or more additional bioactive or functional ingredients. In general, the healthy, shelf-stable food product of the invention is prepared by combining an inoculum of one or more active culture probiotic microorganisms with dairy or soy milk and culturing the inoculated milk to accelerate growth of the microorganisms . The cultured milk, e.g., in the form of a yogurt, may be combined with fruit, flavors, sugar, color, and/or a stabilizer. Optionally, a bioactive such as omega-3 polyunsaturated fatty acids found in marine oils, is added. The pH of the mixture is then adjusted to be optimal for the cultures used (e.g., upwards to a pH of 6.0-6.5 for the Weisby cultures of Example I) . The pH-adjusted yogurt blend is frozen with the inclusion of a gas, e.g., air, and blended with a low moisture food inclusion such as granola or a dried fruit. The frozen mixture is, e.g., molded or extruded into a bar or other intended form. The product is freeze-dried, enrobed if desired, and then packaged.

Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof and from the claims.

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a shelf-stabilized probiotic food, preferably in a predetermined geometric shape such as a bar, cookie or nugget, that includes active culture probiotics in the form of cultured dairy or soy milk products, low moisture food ingredients and, preferably, bioactive (functional) ingredients. The food product of the invention is stable at room temperature

(e.g., 70°F) and maintains its active cultures for six to twelve months or more.

Probiotics are living microorganisms that, upon ingestion in certain numbers exert health benefits beyond inherent basic nutrition. Such health benefits include resistance to lactose intolerance resulting in diarrhea, resistance to food poisoning caused by gram-negative bacteria such as E. coli, resistance to gastritis and ulcers caused by H. pylori, and general enhancement of the immune system. Probiotic bacteria are generally, though not exclusively, lactic acid bacteria and include those organisms listed in Table 1. (See, for example, "Institute of Food Technologists Scientific Status Summary-Probiotics" in Food Technology, Vol.53, No.11, November, 1999; "The Probiotic Solution" in Nutrition Science News, Vol.5, No.12, December, 2000; "Probiotics" in Nutraceuticals World, April, 2000; "Examining the Prebiotic and Probiotic Market" in Nutraceuticals World, April, 2000; and "The Good Bugs" in The Boston Globe, November 21, 2000, page E01.)

Table 1: Examples of probiotic bacteria

La ctobacillus acidophilus

L . caseii

L . bulgaricus L . plantarum

L . paracasei

L . salivarius

L . rhamnosus

L . GG L . j ohnsonii

L . plantarum

L . reuteri

L . LCI

Bifidobacterium bifidum B . longum

B . breve

B . infantis

B . lactis

Streptococcus thermophilus

These organisms are used to culture dairy milk or soy milk (a protein-rich, milk-like liquid obtained by grinding soybeans with water) to produce various cultured products such as dairy yogurt, soy milk yogurt and kefir yogurt .

Low moisture food ingredients include granola (and other) cereals, low moisture fruit pieces, chocolate pieces, low moisture candy and savory low moisture food ingredients such as cheese powders, nuts, dried meats, and dehydrated vegetables. Low moisture ingredients are defined as those containing 0% to 10% water. Moisture- containing inclusions such as raisins may be employed in the bar, but they must be of a sufficiently small amount that, in total, the low moisture ingredients are still less than 10% water. Otherwise, the texture of the resulting final product will be affected. Bioactive ingredients are those that contain levels of biologically active compounds sufficient to impart health benefits or desirable physiologic effects. Some of the bioactive ingredient classes that can fortify the edible bar are prebiotics (which enhance the effectiveness of probiotic microorganisms) ; vitamins/provitamins and antioxidants; nutritional proteins, hydrolysates and amino acids; dietary enzymes; dietary fibers; polyunsaturated fatty acids; minerals; sugar alcohols; and herbals/botanicals . Representative ingredients of various classes and their main health benefits are shown in Table 2. Table 2 : Classes of Bioactive Ingredients and Health Benefits

The freeze-dried, edible bar of the invention delivers the health benefits of the probiotic and the various bioactives and the good flavors of the food inclusions and probiotic in a shelf-stable, convenient- to-eat form. Because of the way the food product of the invention is made (specifically, the incorporation of an aeration step in which the flavored (or formulated) probiotic culture is simultaneously agitated and frozen to incorporate small air bubbles) , the texture of the resulting product with the various food inclusions and bioactive fortification ranges from chewy to crunchy and is not adversely affected by the addition of the probiotic. The bar melts in the mouth.

The probiotic cultures must be alive and active, and the pH of the cultured milk containing the probiotic, in combination with the food inclusions and bioactive ingredients, must be adjusted to be optimal for probiotic culture stability and viability before the end product is freeze dried. pH adjusted viable probiotics survive the freeze drying and optional enrobing process. The probiotic in one embodiment is about 10⁷-10⁹ cfu of food grade lactic acid producing cultures ( S. thermophilus and L. bulgaricus) per gram of product.

In order to achieve these health and texture benefits in the final product, the upper limit inclusion ratio for food ingredients and bioactives to probiotics is at most 2:1 and preferably 1:1 by weight. The lower limit is about 1:25 (and preferably 1:20) inclusion (food ingredient and bioactive) . Not being bound by any theory, it is believed that aeration of the cultured milk, which contains the probiotic microorganisms, prior to incorporation of the low moisture food ingredients, and inclusion of the proper ratio of food ingredients/bioactives to probiotics lead to a resultant product with a unique texture, which is different from merely combining a conventional probiotic, such as yogurt, and conventional food and bioactive ingredients. A freeze-dried probiotic powder mixed with flavorings and pressed into a form, e.g., a tablet or bar is significantly harder and requires significantly more force to fracture than does the food product of the invention and, therefore, would not provide the desired texture and taste.

The following examples are presented to illustrate the advantages of the present invention and to assist one of ordinary skill in making and using the same. These examples are not intended in any way otherwise to limit the scope of the disclosure.

EXAMPLE I Preparation of a Granogurt bar An exemplary embodiment of the edible, shelf- stabilized food product of the invention is described in Table 3 as a Yogurt Snack Formulation or Granogurt . Yogurt is a probiotic involving two live organisms - L . bulgaricus and S. thermophilus . In general, the yogurt is prepared using live and active cultures and then is combined with fruit, flavors, sugar, color, and stabilizer. Optionally, a bioactive such as omega-3 polyunsaturated fatty acids found in marine oils, is added. The pH of the mixture is then adjusted to be optimal for the cultures used (e.g., upwards to a pH of 6.0-6.5 for the Weisby cultures of this example). The pH-adjusted yogurt blend is frozen with the inclusion of air and blended with a low moisture food inclusion such as granola or a dried fruit. The frozen mixture is formed into a bar or other intended form, e.g., by molding or extrusion. The product is freeze-dried and enrobed, if desired, and then packaged. A typical process for manufacturing a Granogurt bar follows .

This novel food product is made by inoculating and mixing sterilized skim milk with probiotic bacteria (e.g., Weisby culture MSK-MixABNl-45) at a 0.075-0.10% level by weight. A Weisby culture is a blend of Lactobacillus, Bifidobacterium and Streptococcus . The mixture (mixture A) is incubated at 108°-110°F for enough time for the pH to reach 4.2 (usually 5-6 hours). The mixture is then refrigerated at 40°F until use. A second mixture (mixture B) is prepared by mixing into skim milk, sugar at a level of 33%, and stabilizer at a level of 1.28%. The stabilizer consists of various vegetable hydrocolloids such as carrageenan, locust bean gum and guar gum. Mixing is achieved utilizing a high-speed blender. Mixture B is heated to 130°F and homogenized at 2000 psi. Mixture B is also refrigerated at 40 °F until use. A third mixture (mixture C) is then prepared by mixing together mixture A (59%), frozen sliced strawberries with sugar (20%), mixture B (19.5%), natural strawberry flavor (1.25%), and red beetroot juice concentrate (0.25%). Various bioactive ingredients can also be added to mixture C at this point, such as marine oil containing polyunsaturated fatty acids. The pH of mixture C is raised by adding a 50% (wt./wt.) solution of NaOH, with stirring, until the pH reaches 6.0-6.5. Mixture C is then frozen in a Gelmark ice cream freezer with air incorporation so that the overrun percentage is 30%. (Percent overrun = [{wt. of mix - wt . of frozen mix}/wt. of frozen mix] x 100). To the frozen, aerated mixture C is added, with stirring, 25.5% of granola cereal composed of a mixture- of whole oats, brown sugar, whole grain wheat, corn syrup, rice and almonds; and 13.0% chopped raisins (mixture D) . Mixture D is spooned into plastic bar molds, inch deep, 4 inches long, and 1 inch wide. The filled bar molds are frozen to -20°F in a freezer. Alternatively, the frozen, aerated product could be extruded in the form of a rod and then sliced into bars. The frozen bars are separated from the molds and placed on a previously chilled metal tray. The tray is then placed in a freeze-drying apparatus, and the bars are subjected to a vacuum of 0.5mm Hg until their moisture content is about 5% by weight. At this point, the bars are dry and shelf-stable. The dry, shelf stable bars are dipped into warm (110 °F) fluid confectioner's coating or chocolate. The coating is allowed to harden at room temperature. The bars are then packaged into a high barrier package containing aluminum foil. For ease of commercial production, the various steps of the method, may be carried out at separate plants in various locations, as long as the basic principles of the method, as described above, are observed.

A simple test to ascertain that the freshly made Granogurt bars contain live and active cultures involves incubating a crumbled portion of a bar in warm, preferably skim, milk and measuring the increase in titratable acidity and the decrease in pH following co- incubation. If the cultures of the Granogurt bar are live and active, the cultured milk also will show an increase in viscosity (thickness) compared with the original skim milk.

Table 3 Yogurt Snack Formulation: Prototypes #28286-100

> 26g

EXAMPLE I I

Comparative Texture Analysis

Two Granogurt bars according to the invention, one coated and one uncoated, were analyzed for hardness and fracturability using a TA.XT2 Texture Analyzer (Texture

Technologies Corp., Scarsdale, NY). The analysis results were compared to those obtained using chewable

Acidophilus (with Bifidus) culture wafers having a natural strawberry flavor, which are available from American Health, Inc., Holbrook, NY and described as "providing 10⁹ microrganisms per wafer at the time of manufacture . " One wafer weighs 1.1 grams .

The TA.XT2 Texture Analyzer utilizes a load cell to measure the force required to maintain a constant rate of penetration to a preset depth. For the determination of hardness and fracturability, a cylinder-shaped probe

("punch probe") of 4mm in diameter is made to travel vertically at 3mm/second until it touches the sample and penetrates it at a lmm/second rate for a distance of 5mm for the Granogurt bar samples and 1.5 mm for the wafer samples. The direction of the probe is reversed, and it then returns to its original position at a rate of lOmm/second. The force required to fracture the sample and compress it to a depth of 5 mm or 1.5 mm, as indicated, is the maximum peak force, defined as sample hardness. The force required to fracture the Granogurt bar or wafer samples is defined as sample fracturability. The results obtained are shown in Table 4. Table 4 : Texture analysis comparison of Granogurt bars with Acidophilus wafers

Granogurt Bar Granoguή Bar Uncoated Coated Wafer

1. Hardness 2949 g 2951g 18,582g

2. Fracturability 1531g 1653g 12,189g

As can be seen from the results shown above, the wafer is roughly six times as hard as the Granogurt bar and requires roughly seven times more force to fracture. The textures of the wafer and Granogurt bar are, therefore, significantly different.

While the present invention has been described in conjunction with a preferred embodiment, one of ordinary skill, after reading the foregoing specification, will be able to effect various changes, substitutions of equivalents, and other alterations to the compositions and methods set forth herein. It is therefore intended that the protection granted by Letters Patent hereon be limited only by the definitions contained in the appended claims and equivalents thereof.

Claims

CLAIMSWhat is claimed is:

1. A method of making an edible product having live and active probiotic microorganisms, said method comprising the steps of: combining an inoculum of one or more active culture probiotic microorganisms with dairy or soy milk; culturing the inoculated milk to accelerate growth of said microorganisms; adjusting the pH of said cultured milk to be optimal for viability of said active culture probiotic microorganisms ; freezing aliquots of said cultured milk with inclusion of a gas so as to aerate said cultured milk; mixing said aerated, frozen cultured milk with one or more low moisture food ingredients in a ratio of from 25:1 to 1:2 by weight to form a mixture; forming the frozen mixture into a shape; and freeze-drying said frozen, shaped mixture to produce said edible product, wherein said product comprises at least 10⁶ cfu of live and active probiotic microorganisms per gram of product.

2. The method of claim 1, further comprising incorporating a flavor, a color or a stabilizer into said said cultured milk, prior to said pH adjustment step. .

3. The method of claim 1, further comprising adding a bioactive ingredient to said cultured milk, prior to said pH adjustment step.

4. The method of claim 1, wherein said milk is a dairy product .

5. The method of claim 1, wherein said milk is a soybean product .

6. The method of claim 1, wherein said cultured milk is in the form of a yogurt .

7. The method of claim 1, wherein said low moisture food ingredients comprise granola.

8. The method of claim 1, wherein said forming step comprises molding said frozen mixture into a predetermined shape.

9. The method of claim 1, wherein said forming step comprises extruding said frozen mixture and dividing said extrudate into separate portions.

10. The method of claim 1, wherein said probiotic microorganisms are lactic acid producing bacteria.

11. The method of claim 10, wherein said probiotic microorganisms are from genera selected from the group consisting of Lactobacillus, Bifidobacterium and Streptococcus .

12. A method of making an edible product having live and active probiotic microorganisms, said method comprising the steps of: obtaining cultured milk prepared by the steps of: combining an inoculum of one or more active culture probiotic microorganisms with dairy or soy milk and culturing the inoculated milk to accelerate growth of said microorganisms; adjusting the pH of said cultured milk to be optimal for viability of said active culture probiotic microorganisms; freezing aliquots of said cultured milk with inclusion of a gas so as to aerate said cultured milk; mixing said aerated, frozen cultured milk with one or more low moisture food ingredients in a ratio of from 25:1 to 1:2 by weight to form a mixture; forming the frozen mixture into a shape; and freeze-drying said frozen, shaped mixture to produce said edible product, wherein said product comprises at least 10⁶ cfu of live and active probiotic microorganisms per gram of product .

13. A shelf-stable probiotic food product made by the process of claim 1 or claim 12.

14. A shelf-stable freeze-dried probiotic food product comprising: one or more active culture probiotic microorganisms in the form of cultured dairy or soy milk; and -If

one or more low moisture food ingredients, wherein said low moisture food ingredients comprise a maximum of 10% water, wherein said cultured milk and said one or more low moisture food ingredients are present in said product in a ratio of from 25:1 to 1:2 (wt:wt), and wherein said product comprises at least 10⁶ cfu of live and active probiotic microorganisms per gram of product.

15. The probiotic food product of claim 13 or 14, further comprising a flavor, a color or a stabilizer.

16. The probiotic food product of claim 13 or 14, further comprising a bioactive ingredient.

17. The probiotic food product of claim 13 or 14, wherein said cultured milk is in the form of a yogurt.

18. The probiotic food product of claim 13 or 14, wherein said low moisture food ingredients comprise granola.

19. The probiotic food product of claim 13 or 14, wherein said product is in the shape of a bar.

20. The probiotic food product of claim 13 or 14, wherein said product is enrobed in chocolate.

21. The probiotic food product of claim 13 or 14, wherein said probiotic microorganisms are from genera selected from the group consisting of Lactobacillus, Bifidobacterium and Streptococcus .