Acidic protein food and method for producing the same

Abstract

The object of the present invention is to provide an acidic protein food that maintains a smooth texture even after freezing and thawing. [Solution] An acidic protein food containing (A) branched starch hydrolysate and (B) unbranched starch hydrolysate with DE of 5 to 28.

Description

Technical Field

[0001] The present invention relates to an acidic protein food having freeze-thaw resistance and a method for producing the same.

Background Art

[0002] In the long-term preservation of foods, frozen storage is a very effective method. However, when many foods are thawed after freezing, they do not return to the same state as before freezing, and the texture and appearance deteriorate. In particular, acidic protein foods are likely to cause protein denaturation when frozen, and the texture after thawing is likely to be impaired.

[0003] As a method for solving this problem, a method for producing frozen soy milk yogurt in which soy milk containing a gelling agent and a lactic acid bacteria starter is fermented and coagulated and then frozen (Patent Document 1), a method for producing a soft cream mix capable of being frozen and distributed by adding native type gellan gum as a stabilizer (Patent Document 2), a method for producing a yogurt-like acidic protein food by adding two or more selected from the group consisting of oligosaccharides having three or more sugars or trehalose, galacturonic acid-containing polysaccharides and starch, and a gelling agent (Patent Document 3) have been proposed.

[0004] However, with these techniques, the acidic protein food after freeze-thawing has roughness and does not necessarily have a satisfactory texture. Further, in Patent Document 3, a gelling agent is required, but it is presumed that the texture inherent to yogurt and the like is affected by the gelling agent.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0006] The object of the present invention is to provide an acidic protein food that maintains a smooth texture even after freezing and thawing. [Means for solving the problem]

[0007] The inventors of the present invention conducted various studies to solve the above problems and found that an acidic protein food containing (A) branched starch hydrolysate and (B) unbranched starch hydrolysate with DE of 5 to 28 can solve the above problems, and thus completed the present invention.

[0008] The present invention includes, but is not limited to, the following embodiments. [1] (A) an acidic protein food containing branched starch hydrolysate and (B) an unbranched starch hydrolysate with a DE of 5 to 28, which is stored frozen. [2] The acidic protein food according to [1], comprising 2.5 to 15% by mass of component (A) and 2.5 to 15% by mass of component (B). [3] Furthermore, the acidic protein food according to [1] or [2], further comprising (C) acid-treated starch. [4] An acidic protein food that is fermented milk, as described in any one of the above [1] to [3]. [5] A method for imparting cold-thaw tolerance to an acidic protein food, comprising (A) a branched starch hydrolysate and (B) a non-branched starch hydrolysate having a DE of 5 to 28 in the acidic protein food. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an acidic protein food that retains a smooth texture even after freezing and thawing. [Modes for carrying out the invention]

[0010] [Acidic protein foods] The acidic protein food of the present invention comprises (A) branched starch hydrolysate and (B) unbranched starch hydrolysate with DE = 5 to 28.

[0011] The acidic protein food of the present invention contains at least one branched starch hydrolysate. The "branched starch hydrolysate" as used in the present invention is a starch hydrolysate that has undergone a treatment (branching treatment) that increases the number of branched bonds of any of the 1,2-glucosidic bonds, 1,3-glucosidic bonds, and 1,6-glucosidic bonds compared to its raw starch, and also includes its reduced product. Examples of branching treatment include roasting the starch or its hydrolysate, roasting treatment, or branch formation by the addition or transfer of sugars by enzymatic reactions. The roasting temperature is preferably 120°C to 200°C, more preferably 150°C to 200°C. During roasting, it is preferable that the moisture content of the starch or its hydrolysate is 5% or less.

[0012] Examples of such branched starch hydrolysates include branched dextrin and indigestible dextrin. Branched dextrin can be produced, for example, by treating starch with maltose-producing amylase and transglucosidase (see, for example, WO2009 / 113652). Indigestible dextrin can be produced, for example, by treating roasted dextrin with α-amylase and glucoamylase to extract dietary fiber (see, for example, Japanese Patent Publication No. 2-154664).

[0013] The acidic protein food of the present invention contains at least one non-branched starch hydrolysate. In this invention, "non-branched starch hydrolysate" refers to a starch hydrolysate that has not undergone treatment to increase branching. Non-branched starch hydrolysates can be produced, for example, by decomposing starch with acid or hydrolytic enzymes (such as α-amylase).

[0014] The DE of the non-branched starch hydrolysate used in the present invention is 5 to 28, and from the viewpoint of more significantly exhibiting the effects of the present invention, it is preferably 7 to 24, more preferably 7 to 22, even more preferably 7 to 16, and even more preferably 7 to 12. In this specification, "DE" (abbreviation for Dextrose Equivalent) is an indicator of the reducing sugar content and is a value obtained by "[(mass of direct reducing sugar (expressed as glucose)) / (mass of solids)] × 100". In this specification, DE is measured by the Willstetter-Schudel method. In this specification, a non-branched starch hydrolysate with a DE of 5 to 28 is used to mean that it includes its reduced product.

[0015] The raw starches for branched and unbranched starch hydrolysates are not particularly limited and may be one or more selected from the group consisting of tapioca starch, waxy tapioca starch, sweet potato starch, potato starch, corn starch, waxy corn starch, and rice starch.

[0016] The term "acidic protein food" as used in this invention is not particularly limited, as long as it is a food (including beverages) that contains protein and exhibits acidity. In such acidic protein foods, the protein is destabilized due to the low pH, and the protein denatures under freezing conditions, making it easy to lose its smooth texture. The acidic protein food of this invention is preferably soft and fluid when consumed. The acidic protein food of this invention may be, for example, gel-like, paste-like, or liquid-like.

[0017] As for the protein, one or more proteins can be used, for example, milk protein, egg protein, soy protein (e.g., soy protein, mung bean protein, pea protein, etc.), wheat protein, corn protein, meat protein, and proteins consisting of these hydrolysates. However, at least one selected from the group consisting of milk protein and soy protein is preferred, at least one selected from the group consisting of milk protein and soy protein is more preferred, and milk protein is even more preferred.

[0018] Examples of acidic protein foods include dairy products (such as yogurt, cream, butter, cheeses, etc.); frozen desserts (such as ice cream, ice milk, lacto ice, etc.); flower paste; tofu products; beverages (such as milk beverages, fermented milk beverages, soy milk beverages, etc.). Among these acidic protein foods, fermented milk (including yogurt, fermented milk beverages, etc.) is preferred in that the effects of the present invention are more likely to be significantly exerted.

[0019] As used herein, "fermented milk" refers to those obtained by fermenting animal milk such as cow's milk, goat's milk, sheep's milk, etc., those obtained by fermenting soy milk, and those obtained by fermenting a dispersion obtained by dispersing soy proteins such as soy flour, concentrated soy protein, and isolated soy protein in water. The "fermented milk" in this specification includes "fermented milk", "lactic acid bacteria beverage", "milk beverage", and "natural cheese" in the ordinance regarding the ingredient standards of milk and dairy products (Ordinance on Milk, etc.). The microorganisms used for fermentation are not particularly limited, and lactic acid bacteria, yeast, etc. can be used. The non-fat milk solids content and viable lactic acid bacteria count in fermented milk are also not particularly limited.

[0020] The form of fermented milk is not particularly limited and can be solid, liquid, paste, powder, etc.

[0021] The protein content of the acidic protein food can be appropriately changed depending on its form, the types and amounts of components (A) and (B) contained therein, but is preferably 1% by mass or more, more preferably 1.5% by mass or more, still more preferably 2% by mass or more, even more preferably 2.5% by mass or more, and is, for example, 30% by mass or less, 20% by mass or less, 10% by mass or less, 5% by mass or less, or 4.5% by mass or less. The higher the protein concentration, the more likely the protein is to be destabilized under freezing conditions, and the more significant the improvement effect according to the present invention becomes.

[0022] The pH of the acidic protein food of the present invention is preferably 6 or less, for example 5 or less, 5.5 or less, 5 or less, 4.8 or less, more preferably 4.6 or less, even more preferably 4.4 or less, even more preferably 4.2 or less, and particularly preferably 4.0 or less. The lower the pH, the more easily the protein becomes unstable under freezing conditions, and the improvement effect of the present invention becomes more pronounced.

[0023] The branched starch hydrolysate contained in the acidic protein food of the present invention is, for example, 0.01 to 30% by mass, 0.1 to 20% by mass, or 1 to 20% by mass relative to the total amount of food, and is preferably 2.5 to 15% by mass, more preferably 5 to 10% by mass, from the viewpoint of more significantly exhibiting the effects of the present invention.

[0024] The unbranched starch hydrolysate with DE=5-28 contained in the acidic protein food of the present invention is, for example, 0.01% by mass or more, 0.1% by mass or more, or 1% by mass or more, relative to the total amount of food, and from the viewpoint of more significantly exhibiting the effects of the present invention, it is preferably 2.5% by mass or more, more preferably 5% by mass or more, relative to the total amount of food. From the viewpoint of suppressing the influence on the sweetness of the food, the unbranched starch hydrolysate with DE=5-28 contained in the acidic protein food of the present invention is, for example, 20% by mass or less, preferably 15% by mass or less, more preferably 1-20% by mass, relative to the total amount of food.

[0025] The content of component (B) in the acidic protein food of the present invention relative to 1 part by mass of component (A) is, for example, 0.1 to 10 parts by mass, 0.1 to 5 parts by mass, or 0.1 to 2 parts by mass.

[0026] The content of component (A) in the acidic protein food of the present invention, per 1 part by mass of protein, is, for example, 0.3 to 3 parts by mass, 0.5 to 3 parts by mass, or 1.5 to 3 parts by mass.

[0027] In addition to protein, branched starch hydrolysate, and unbranched starch hydrolysate, the acidic protein food of the present invention may contain, to the extent that it does not impair the effects of the present invention, materials commonly used in acidic protein foods, such as starch, sweeteners, thickening polysaccharides, emulsifiers, vitamins, minerals, amino acids, dietary fiber, fruit juice, cocoa powder, coffee, black tea, acidulants, seasonings, colorings, and flavorings.

[0028] Among these, the use of acid-treated starch as a raw material is preferable because it can impart a rich texture without adversely affecting the texture of acidic protein foods. The raw material starch for acid-treated starch is not particularly limited, but waxy potato starch and waxy tapioca starch are preferred. Furthermore, the viscosity of a 4% (w / v) aqueous solution of the acid-treated starch at 30°C is, for example, 100 mPa·s or less, preferably 50 mPa·s or less, more preferably 20 mPa·s or less, for example, 1 mPa·s or more, 2 mPa·s or more, or 3 mPa·s or more. From the viewpoint of having a good texture, the content of acid-treated starch is, for example, 2 to 8% by mass of the total amount of food.

[0029] The acidic protein food of the present invention retains the same smooth texture as before freezing, even after freezing and thawing. Therefore, the acidic protein food of the present invention can be frozen and stored and distributed as a frozen acidic protein food. While the frozen acidic protein food of the present invention is generally consumed after freezing and thawing, it can also be consumed while still frozen.

[0030] The freezing temperature of the acidic protein food of the present invention is not particularly limited, but is, for example, -10°C or lower, preferably -20°C or lower.

[0031] The acidic protein food of the present invention can be prepared by conventional methods depending on its form. ru.

[0032] The acidic protein food of the present invention maintains a smooth texture after thawing compared to when component (A) or component (B) is used alone, by combining component (A) and component (B).

[0033] [Method for imparting freeze tolerance to acidic protein foods] The present invention relates to a method for adding acidic protein to food products through freezing, which includes incorporating (A) a branched starch hydrolysate and (B) a non-branched starch hydrolysate with a DE of 5 to 28 into the acidic protein food product.

[0034] The specific forms of component (A), component (B), and acidic protein food, as well as the freezing conditions, etc., are the same as those described in the [acidic protein food] section above.

[0035] The present invention will be described in detail and specifically below with reference to experimental examples, but the present invention is not limited to these experimental examples. [Examples]

[0036] The present invention will be described in detail and specifically below with reference to examples, but the present invention is not limited to these examples. In the following examples, unless otherwise specified, "parts" refers to parts by mass, and "%" refers to mass percent. Also, unless otherwise specified, the amounts in the tables refer to parts by mass.

[0037] (Test food) Table 1 shows the starch hydrolysates used in the tests described below (all manufactured by Matsutani Chemical Industry Co., Ltd.).

[0038] [Table 1]

[0039] The yogurt used in the following test examples was prepared using the method shown in Table 2.

[0040] [Table 2]

[0041] (Sensory evaluation) The test food was prepared by letting the yogurt stand at -40°C for 2 hours, then at -20°C for more than 12 hours before freezing. The frozen yogurt was removed from the freezer and thawed at 25°C for 1 hour. The thawed food was evaluated by individuals engaged in research and development and skilled in sensory evaluation according to the criteria in Table 3.

[0042] [Table 3]

[0043] Test Example 1. Combined effect of "branched starch hydrolysate" and "non-branched starch hydrolysate" Yogurt was prepared using the formulations listed in Table 4. The results of the evaluation of the yogurt's texture after freezing and thawing are shown in Table 4.

[0044] [Table 4]

[0045] As shown in Table 4, the yogurts containing both branched and unbranched starch hydrolysates (Examples 1 and 2) had a very smooth and good texture after freezing and thawing. On the other hand, the yogurts containing only branched starch hydrolysates (Comparative Examples 1 and 2) or only unbranched starch hydrolysates (Comparative Example 3) had a rough texture after freezing and thawing.

[0046] 2. Effect of DE on "non-branched starch hydrolysates" used in combination with "branched starch hydrolysates" Yogurt was prepared by replacing the unbranched starch hydrolysate of Example 1 with unbranched starch hydrolysate DE4, 9, 18, or 22. The results of the sensory evaluation of the smoothness after thawing are shown in Table 5. When the DE of the non-branched starch hydrolysate used was 9, 18, or 22, the yogurt had a smooth texture after freezing and thawing. When a non-branched starch hydrolysate with a DE of 4 was used, a slight graininess was felt, so a DE of 5 or higher is considered preferable.

[0047] [Table 5]

[0048] 3. The effect of the blending ratio of "branched starch hydrolysate" and "non-branched starch hydrolysate" Yogurt was prepared in the same manner as in Example 1, except for the amounts of milk, branched starch hydrolysate, and unbranched starch hydrolysate. The results of the texture evaluation after freezing and thawing are shown in Table 6. When the yogurt contained branched starch hydrolysates and unbranched starch hydrolysates in amounts of 5%, 8%, and 10% by mass, the yogurt had a smooth texture after freezing and thawing. Furthermore, when the amounts of branched starch hydrolysates and unbranched starch hydrolysates were 7% and 3%, or 9% and 1%, respectively, the yogurt also had a smooth texture after freezing and thawing.

[0049] [Table 6]

Claims

1. An acidic protein food containing (A) branched starch hydrolysate and (B) unbranched starch hydrolysate with a DE of 5 to 28, which is stored frozen.

2. The acidic protein food according to claim 1, comprising 2.5 to 15% by mass of component (A) and 2.5 to 15% by mass of component (B).

3. Furthermore, the acidic protein food according to claim 1 or 2, further comprising (C) acid-treated starch.

4. The acidic protein food according to claim 1 or 2, which is fermented milk.

5. A method for imparting cold-thaw tolerance to an acidic protein food, comprising incorporating (A) a branched starch hydrolysate and (B) a non-branched starch hydrolysate having a DE of 5 to 28 into the acidic protein food.

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