Patent Application
20250151743
The present invention relates to the field of modified milk, and in particular, to a modified milk having a yeast extract containing gamma-aminobutyric acid and a preparation method therefor.
There are many liquid milks on the market today, which are often made by adding thickening agents, emulsifiers, sweeteners, etc to the milk.
In recent years, with the acceleration of overall social life rhythm and the impact from all aspects, an increasing number of residents have sleep problems.
With the development of science and technology, scientists have gradually recognized that gamma-aminobutyric acid (GABA) is a non-protein constitutive amino acid widely distributed in animals, plants, and microorganisms, which has physiological activities such as lowering blood pressure, lowering blood sugar, calming nerves, anti-anxiety, sleep aid, and enhancing kidney function. Relevant studies have shown that GABA can bind to anti-anxiety receptors in the brain and activate the enzyme system in the central nervous system. The whole nervous system can cooperate with other substances to prevent the nervous system from receiving anxiety-related information and cut off transmission pathways, thus playing a role in tranquilizing and allaying, anti-anxiety, and sleep aid. By inhibiting the decarboxylation of glutamic acid, GABA can promote more glutamic acid to combine with ammonia to generate urea to be discharged from the body, thereby relieving ammonia toxicity and improving human liver and kidney function. Many clinical trials have shown that gamma-aminobutyric acid has a significant effect on anti-anxiety, sleep aid, and other aspects, and the country has also included it in the list of new resource foods.
In view of the anti-anxiety, sleep aid, and other effects of gamma-aminobutyric acid, it has been proposed in the prior art to add gamma-aminobutyric acid to liquid milk products to improve sleep quality and inhibit anxiety while ingesting milk nutrition. The inventors have been engaged in yeast research for a long time and have found that the yeast extract prepared by a specific method contains GABA, and the addition of the freshly-prepared yeast extract containing GABA to liquid milk has specific advantages over those prepared according to existing methods.
Accordingly, it is an object of the present invention to provide a modified milk having a yeast extract containing gamma-aminobutyric acid and a preparation method therefor, which can introduce the health function and nutritional value of gamma-aminobutyric acid while improving the mouthfeel and flavor of the product.
In a first aspect, the present invention provides a modified milk, comprising, in a total of 1,000 parts by weight of ingredients: 800-970 parts of raw milk, 0.1-10 parts of a yeast extract containing gamma-aminobutyric acid, 0-4 parts of a thickening agent, 0-3 parts of an emulsifier, 0-1 parts of an acidity regulator, 0-130 parts of a sweetener, and 0-2 parts of a flavor essence, with the balance being water, wherein the thickening agent and the emulsifier cannot be absent at the same time.
Preferably, the modified milk comprises, in a total of 1,000 parts by weight of ingredients: 810-960 parts of raw milk, 0.1-10 parts of a yeast extract containing gamma-aminobutyric acid, 0.28-3.8 parts of a thickening agent, 0.5-3 parts of an emulsifier, 0.3-0.9 parts of an acidity regulator, 10-130 parts of a sweetener, and 0.5-2 parts of a flavor essence, with the balance being water.
Preferably, according to the modified milk above, the raw milk is fresh milk, reconstituted milk, partially skimmed milk, or skimmed milk.
Preferably, according to the modified milk above, the partially skimmed milk or the skimmed milk is obtained by adjusting the fat content of the fresh milk or the reconstituted milk by centrifugation.
Preferably, according to the modified milk above, the yeast extract containing gamma-aminobutyric acid is derived from a yeast fermentation process.
Preferably, the modified milk further comprises one or two or more selected from the group consisting of a nutrient-enhancing substance, a cereal ingredient, a fruit and vegetable ingredient, and a water-soluble dietary fiber;
Preferably, the modified milk further comprises 1-15 parts of a water-soluble dietary fiber; more preferably, the water-soluble dietary fiber is polydextrose.
Preferably, according to the modified milk above, the yeast extract containing gamma-aminobutyric acid is obtained by the yeast fermentation process comprising the steps of:
Preferably, according to the modified milk above, the thickening agent comprises one or two or more selected from the group consisting of cyclodextrin, gum arabic, acetate starch, guar gum, pectin, sodium alginate, potassium alginate, locust bean gum, xanthan gum, methylcellulose, gellan gum, sodium polyacrylate, carrageenan, distarch phosphate, gelatin, hydroxypropyl starch, carboxypropyl methyl cellulose, agar, sodium carboxymethyl cellulose, microcrystalline cellulose, acetylated distarch phosphate, and acetylated distarch oxalate. Preferably, according to the modified milk above, the emulsifier comprises one or two or more selected from the group consisting of propylene glycol fatty acid ester, mono- and diglycerides of fatty acids, succinylated monoglyceride, polyglycerol fatty acid ester, polyoxyethylene sorbitan monolaurate, diacetyl tartaric acid ester of mono(di)glycerides, sucrose fatty acid ester, phospholipid, modified soybean phospholipid, enzymatically hydrolyzed soybean phospholipid, sodium caseinate, lactic acid fatty acid glyceride, and acetylated mono- and diglycerides of fatty acids, preferably mono- and diglycerides of fatty acids mixture that may be a mixed ester formed from any fatty acid and glycerol. For example, the mono- and diglycerides of fatty acids in the present invention may be a mixed ester formed from one or two or more selected from the group consisting of oleic acid, linoleic acid, linolenic acid, palmitic acid, behenic acid, stearic acid, and lauric acid, and glycerol; it may be mono- and diglycerol stearate mixture, wherein the mono- and diglycerol fatty acid ester has a monoglycerol fatty acid ester content of 95% or more (monoglycerol stearate are preferred in the present invention). Similarly, the “fatty acid ester” in the “polyglycerol fatty acid ester,” the “sucrose fatty acid ester,” and the “acetylated mono- and diglycerides of fatty acids” used in the present invention may be any ester formed from any fatty acid and glycerol, sucrose, and acetylated glycerol, respectively. Specifically, the “fatty acid ester” may be one or two or more selected from the group consisting of oleic acid, linoleic acid, linolenic acid, palmitic acid, behenic acid, stearic acid, and lauric acid.
Preferably, according to the modified milk above, the acidity regulator comprises one or two or more selected from the group consisting of phosphoric acid and salts thereof, citric acid and salts thereof, malic acid and salts thereof, lactic acid and salts thereof, carbonic acid and salts thereof.
Preferably, according to the modified milk above, the sweetener comprises one or two or more selected from the group consisting of white granulated sugar, glucose-fructose syrup, crystalline fructose, honey, stevioside, erythritol, mogroside, maltitol, sucralose, acesulfame-K, neotame, and sodium cyclamate.
In a second aspect, the present invention provides a method for preparing the modified milk above, comprising the steps of:
According to the above method, the content of raw milk used in step (1) accounts for 25 wt %-60 wt % of the total content of raw milk.
Preferably, according to the above method, in step (1), the raw milk is heated to dissolve other materials at a temperature of 60-75° C.
Preferably, according to the above method, in step (1), the raw milk is sheared and stirred to dissolve other materials, the time of shearing and stirring is 15-20 min.
Preferably, according to the above method, in step (2), the temperature of homogenization is 60-75° C., and the pressure of homogenization is 70/250 bar.
Moreover, the method further comprises testing the product quality after homogenization and before sterilization, or testing the quality after sterilization; or testing the quality of the semi-finished product obtained in step (2) before homogenization; preferably testing the quality after sterilization, followed by canning to obtain a modified milk.
Specifically, when the quality of the semi-finished product obtained in step (2) is tested, the protein and acidity indicators of the semi-finished product are tested, in which the protein content of the semi-finished product shall be ≥2.3%, the acidity shall be 15-18° T, and the pH value shall be 6.3-7.0.
The modified milk of the present invention can combine excellent mouthfeel and balanced functional nutrition. It has not only the functionality of gamma-aminobutyric acid, but also a rich, creamy, and milky flavor as well as smooth texture, and is free of distinctive irritating yeast odor.
According to the present invention, the technical problem of both mouthfeel and functional nutrition not being able to be achieved is solved by adding a freshly prepared yeast extract containing gamma-aminobutyric acid directly to raw milk.
The yeast extract containing gamma-aminobutyric acid used in the present invention is prepared by the following steps: fermenting a conventional yeast to prepare yeast milk and adding 0.5%-5 wt %, preferably 1%-2 wt %, of citric acid; then heating the obtained yeast milk at 40° C.-70° C., preferably 50-60° C.; maintaining the pH of the yeast milk after heating, and continuing to maintain the temperature for 0.5-3 h, preferably 1-2 h; after that, controlling the pH between 4.0 and 7.0, preferably between 5.0 and 6.0, using citric acid; continuing the autolysis of the yeast milk under the above pH condition for 2-8 h, preferably 3-5 h; separating the yeast milk after completion of the reaction with hot water, evaporating and concentrating the separated clear liquid to obtain a yeast extract product containing gamma-aminobutyric acid in a paste state.
Preferably, the following specific yeast strains are used in the present invention to prepare the yeast extract product containing gamma-aminobutyric acid:
1. Saccharomyces cerevisiae—strain name: Saccharomyces cerevisiae FX-2; accession number: CCTCC NO: M2016418; deposit date: Aug. 1, 2016; depository: China Center for Type Culture Collection (CCTCC); address: Wuhan University, Wuhan, China, 430072, fax: (027) 68754833; specifically disclosed in the patent literature CN108220175A (application number: 201611141122.8).
2. Wickerhamomyces anomalus—strain name: Wickerhamomyces anomalus C1.7; accession number: CCTCC NO: M2017782; deposit date: Dec. 11, 2017; depository: China Center for Type Culture Collection (CCTCC); address: Wuhan University, Wuhan, China, 430072, fax: (027) 68754833; specifically disclosed in the patent literature CN110959853A (application number: 201811152248.4).
3. Cyberlindnera fabianii—strain name: Cyberlindnera fabianii C1.8; accession number: CCTCC NO: M2017780; deposit date: Dec. 11, 2017; depository: China Center for Type Culture Collection (CCTCC); address: Wuhan University, Wuhan, China, 430072, fax: (027) 68754833; specifically disclosed in the patent literature CN110959853A (application number: 201811152248.4).
The yeast milk is obtained by the following steps: adding a yeast strain to a sterilized glucose solution, with an inoculation amount of the strain of 15 g/L-30 g/L, and activating to obtain a yeast seed solution; adding the yeast seed solution to a fermentation medium and fermenting to obtain a fermentation broth; centrifuging the fermentation broth and washing the heavy phase to obtain a washed yeast; formulating the washed yeast with water to obtain the yeast milk.
The fermentation conditions are as follows: pH 3.0-5.0, culture temperature 30-33° C., and culture time 10-20 hours.
The fermentation medium contains the following components in mass per 100 milliliters of medium: 3-5 g of a carbon source, 0.5-1 g of a yeast extract, 1-2 g of ammonium sulfate, 0.5-1 g of magnesium sulfate, 0.3-0.5 g of potassium dihydrogen phosphate, and 0.1-0.2 g of zinc sulfate.
The carbon source comprises one or two or more selected from the group consisting of cane molasses, beet molasses, and starch hydrolyzing sugars.
The centrifugation of the fermentation broth is performed by centrifuging at 5000-7000 rpm for 5-15 minutes, discarding the supernatant, and retaining the heavy phase.
The washing of the heavy phase is performed by dissolving the heavy phase with water, re-centrifuging, discarding the supernatant, re-dissolving the re-obtained heavy phase with water, centrifuging, and discarding the supernatant to obtain a washed yeast.
The modified milk of the present invention may further be added with one or two or more selected from the group consisting of a nutrient-enhancing substance, a cereal ingredient, a fruit and vegetable ingredient, and a water-soluble dietary fiber, with a total of 1,000 parts by weight of ingredients.
If fresh milk is used as an initial ingredient, the method for preparing a modified milk having a yeast extract containing gamma-aminobutyric acid according to the present invention comprises the steps of:
Various indicators of the liquid milk product having a yeast extract containing gamma-aminobutyric acid prepared according to the above process meet the national standard for modified milk.
The technical solution of the present invention will be described in detail with reference to the examples below. Apparently, the described examples are merely some rather than all of the examples of the present invention. All other examples obtained by a person of ordinary skill in the art based on the examples of the present invention without creative efforts shall fall within the protection scope of the present invention.
The yeast extract containing gamma-aminobutyric acid used in all examples is a fresh yeast extract made by fermentation.
The sources of each material used in the following Examples and Comparative Examples are shown in Table A below.
2. Preparation method
The pre-homogenization parameter was 50/200 bar, i.e., the secondary pressure was first adjusted to 50 bar, and the primary pressure was then adjusted to 200 bar.
The sterile liquor obtained in the process (8) was aseptically canned.
Various indicators of the finished product were tested according to the steps described in the “Evaluation test method for product mouthfeel” in the following text of the present application. The specific test results are shown in Table 2.
1. In this example, the ratio of each ingredient was based on the total weight of the modified milk as follows:
820‰ of fresh milk, 10‰ of white granulated sugar, 10‰ of polydextrose, 5‰ of a yeast extract containing gamma-aminobutyric acid, 2.0‰ of microcrystalline cellulose, 0.3‰ of disodium hydrogen phosphate, 5‰ of oat grains, 0.06‰ of sucralose, and 1.2‰ of a food flavor essence, with the balance being water.
2. Preparation method
The pre-homogenization parameter was 50/200 bar, i.e., the secondary pressure was first adjusted to 50 bar, and the secondary pressure was then adjusted to 200 bar.
The sterile liquor obtained in the process (10) was aseptically canned.
Various indicators of the finished product were tested according to the steps described in the “Evaluation test method for product mouthfeel” in the following text of the present application. The specific test results are shown in Table 2.
1. In this example, the ratio of each ingredient was based on the total weight of the modified milk as follows:
2. Method
The pre-homogenization parameter was 50/200 bar, i.e., the secondary pressure was first adjusted to 50 bar, and the secondary pressure was then adjusted to 200 bar.
The sterile liquor obtained in the process (8) was aseptically canned.
Various indicators of the finished product were tested according to the steps described in the “Evaluation test method for product mouthfeel” in the following text of the present application. The specific test results are shown in Table 2.
In this example, the ratio of each ingredient was based on the total weight of the modified milk as follows:
Except that the specific content of each component involved was different from those in Example 4 as described above, the modified milk was prepared by using the same operation steps as in Section 4.2 of Example 4. Various indicators of the prepared modified milk finished product were tested according to the steps described in the “Evaluation test method for product mouthfeel” in the following text of the present application. The specific test results are shown in Table 2.
In this example, the ratio of each ingredient was based on the total weight of the modified milk as follows:
820‰ of fresh milk, 10‰ of white granulated sugar, 10‰ of polydextrose, 5‰ of a yeast extract containing gamma-aminobutyric acid, 3.8‰ of microcrystalline cellulose, 0.9‰ of disodium hydrogen phosphate, 5‰ of oat grains, 0.06‰ of sucralose, and 1.2% of a food flavor essence, with the balance being water.
Except that the specific content of each component involved was different from those in Example 3 as described above, the modified milk was prepared by using the same operation steps as in Section 3.2 of Example 3. Various indicators of the prepared modified milk finished product were tested according to the steps described in the “Evaluation test method for product mouthfeel” in the following text of the present application. The specific test results are shown in Table 2.
In this example, the ratio of each ingredient was based on the total weight of the modified milk as follows:
Except that the specific content of each component involved was different from those in Example 2 as described above, the modified milk was prepared by using the same operation steps as in Section 2.2 of Example 2, in which the material dissolution process was performed by dissolving the thickening agent, the emulsifier, the sweetener, and the acidity regulator in fresh milk. Various indicators of the prepared modified milk finished product were tested according to the steps described in the “Evaluation test method for product mouthfeel” in the following text of the present application. The specific test results are shown in Table 2.
In this example, the ratio of each ingredient was based on the total weight of the modified milk as follows:
Except that the specific content of each component involved was different from those in Example 1 as described above, the modified milk was prepared by using the same operation steps as in Section 2.2 of Example 2. Various indicators of the prepared modified milk finished product were tested according to the steps described in the “Evaluation test method for product mouthfeel” in the following text of the present application. The specific test results are shown in Table 2.
In this example, the ratio of each ingredient was based on the total weight of the modified milk as follows:
In this example, the ratio of each ingredient was based on the total weight of the modified milk as follows:
1. Formula: 820‰ of fresh milk, 10‰ of white granulated sugar, 10‰ of polydextrose, 0.73‰ of gamma-aminobutyric acid, 0.5‰ of mono- and diglycerides of fatty acids, 0.06‰ of sucralose, and 1.2‰ of a food flavor essence, with the balance being water.
2. Preparation method
The pre-homogenization parameter was 50/200 bar, i.e., the secondary pressure was first adjusted to 50 bar, and the secondary pressure was then adjusted to 200 bar.
The sterile liquor obtained in step (8) was aseptically canned.
Various indicators of the finished product were tested.
Fifteen professional evaluators were selected to taste the modified milk of Examples 1-3 and Comparative Example 1. The sensory content included odor, taste, appearance, and mouthfeel. The evaluation criteria are shown in Table 1, and the evaluation results are shown in Table 2.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202210861656.7 | Jul 2022 | CN | national |
This application is a Continuation-in-Part of International Patent Application No. PCT/CN2023/107574, filed Jul. 14, 2023, which claims the benefit of priority to Chinese Patent Application No. 202210861656.7 filed on Jul. 20, 2022. Each of the aforementioned applications are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2023/107574 | Jul 2023 | WO |
| Child | 19019916 | US |
