Oat-based fermented milk and preparation method thereof

Abstract

The invention discloses oat-based fermented milk and a preparation method thereof, and belongs to the technical field of oat processing. Comprising the following steps: cooking and pulping oat, then inoculating a microbial agent, and after fermentation is completed, performing low-temperature after-ripening to obtain the oat-based fermented milk. Through fermentation, the variety of bitter amino acids is reduced, so that the taste of the fermented milk is improved, and the flavor of the oat fermented milk is more harmonious. And meanwhile, the content of aromatic amino acids is remarkably increased, the flavor level of the fermented milk is improved, and the generated flower and fruit aroma components can be mutually set off with the sour taste of acid substances, so that the sour taste is softer and fresher. A large amount of lactic acid is generated through fermentation, and the lactic acid is a main source of sourness in the fermented milk and can reduce the pH value, prolong the shelf life of the product and endow the fermented milk with a unique flavor. Oxalic acid and fumaric acid are reduced, so that the irritant sour taste is weakened, the mouth feel is softer, and the sensory quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of oat processing, in particular to an oat-based fermented milk and a preparation method thereof. Background Art

[0002] Oats are a plant of the genus Avena in the Poaceae family. They are mainly distributed in major producing countries such as Russia, Canada, the United States, Germany and China. They are one of the eight major food crops for mankind and one of the best complete nutritional cereal foods currently available. They were first planted in my country more than 2,000 years ago and are mainly distributed in Inner Mongolia, Hebei and Gansu.

[0003] From a nutritional point of view, oats contain high levels of protein, fat, water-soluble dietary fiber, minerals, vitamins and other nutrients; from a functional point of view, oats contain the highest content of water-soluble dietary fiber β-glucan among all cereals. β-glucan is an effective ingredient for lowering blood lipids and has a significant effect on maintaining blood sugar balance and inhibiting cholesterol absorption. Among cereals, people are increasingly interested in oats due to the balanced amino acid composition, neutral flavor and low allergy of oat protein. As a nutritious and healthy food, oat yogurt has high nutritional value and unique flavor, and has huge market prospects and development potential.

[0004] At present, the production process of oat fermented milk mainly includes the steps of washing, soaking, grinding, fermentation, filling and packaging of oats. However, in the fermentation step, if the environmental conditions such as temperature, humidity and fermentation time are not well controlled, the growth and metabolism of lactic acid bacteria will be affected, the lactic acid content will be insufficient, the acidity of oat fermented milk will be insufficient, the taste will not be sour enough, and the content of various beneficial nutrients will be reduced, thus affecting the quality of oat fermented milk. Summary of the invention

[0005] The purpose of the present invention is to provide an oat-based fermented milk and a preparation method thereof to solve the problems existing in the above-mentioned prior art. The present invention provides a suitable fermentation environment and a processing technology for improving the nutrition, flavor and sensory quality of oat-based fermented milk.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] One of the technical solutions of the present invention is a method for preparing oat-based fermented milk, comprising the following steps:

[0008] The oats are steamed and ground, then inoculated with microbial agents, and after fermentation, are post-ripened at low temperature to obtain the oat-based fermented milk.

[0009] The second technical solution of the present invention is the oat-based fermented milk prepared by the preparation method.

[0010] Based on the above technical solution, the present invention has the following technical effects:

[0011] The present invention provides a method for preparing oat-based fermented milk. After fermentation, the types of bitter amino acids in the fermented milk are reduced, which helps to improve the taste of the fermented milk and make the flavor of the fermented milk more harmonious. At the same time, the content of aromatic amino acids is significantly increased, which improves the flavor level of the fermented milk. The produced floral and fruity aroma components can set off the sour taste of acidic substances, making the sour taste softer and fresher. After fermentation, a large amount of lactic acid is produced. Lactic acid is the main source of sour taste in fermented milk. It can reduce the pH value, extend the shelf life of the product, and give the fermented milk a unique flavor. The reduction of oxalic acid and fumaric acid weakens the irritating sour taste, makes the taste softer, and improves the sensory quality. After fermentation, the number of flavor substances in the oat milk increases, making the aroma and taste better and bringing a richer taste. The increase of volatile acid substances interacts with other flavor components in the fermented milk, thereby enriching the flavor level and making it have a relatively lasting flavor. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 Changes in organic acid content.

[0014] Figure 2 This is a picture of the finished product of oat-based fermented milk. DETAILED DESCRIPTION

[0015] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0016] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0017] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0018] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0019] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0020] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0021] The embodiment of the present invention provides a method for preparing oat-based fermented milk, comprising the following steps:

[0022] The oats are steamed and ground, then inoculated with microbial agents, and after fermentation, are post-ripened at low temperature to obtain the oat-based fermented milk.

[0023] In some specific embodiments, the cooking time is 20 minutes.

[0024] In some specific implementation schemes, the pulping conditions are: solid-liquid ratio is 1:10 (g:mL), 3% edible oil is added, the beating time is 18 minutes, and after the beating is completed, it is filtered through 100-200 mesh gauze.

[0025] In some specific embodiments, the microbial agent is composed of Lactobacillus plantarum, Lactobacillus reuteri, Lactobacillus paracasei, Streptococcus thermophilus and Lactobacillus bulgaricus in a mass ratio of 1:3:2:1:1.

[0026] In some specific embodiments, the fermentation conditions include: adding 9 g / 100 mL of white sugar and 0.35 g / 100 mL of microbial agent to the oat homogenate, and fermenting at 37° C. for 10 hours.

[0027] In some specific embodiments, the low-temperature ripening conditions are: refrigerated ripening at 4°C to 6°C for 12 to 24 hours.

[0028] The embodiment of the present invention also provides oat-based fermented milk prepared by the preparation method.

[0029] In the embodiments of the present invention, Lactobacillus plantarum, Lactobacillus reuteri, Lactobacillus paracasei, Streptococcus thermophilus and Lactobacillus bulgaricus were purchased from Taobao store Chuanxiu flagship store.

[0030] The cooking method described in the embodiment of the present invention is: boiling water bath for 20 minutes

[0031] Example 1

[0032] A preparation method of oat-based fermented milk:

[0033] (1) Raw material selection: Select oatmeal with full grains, pure color and no odor for washing;

[0034] (2) Steaming: Steam the washed oatmeal for 20 min;

[0035] (3) grinding: the oatmeal after cooking is put into a juicer for beating, the beating material-liquid ratio is 1:10 (g:mL), 3g / 100mL of edible oil is added, the beating time is 18min, and after beating, the oatmeal is filtered through a 100-200 mesh gauze;

[0036] (4) Adding main ingredients and supplementary ingredients: Add 100 mL of oat pulp and 9 g / 100 mL of white sugar to the fermentation bottle and stir evenly to fully dissolve the white sugar;

[0037] (5) Sterilization: Seal the fermentation bottle and sterilize it in a 90°C water bath for 20 min;

[0038] (6) Inoculation: The sterilized fermentation tank was cooled naturally to 40°C to 42°C and inoculated with Lactobacillus plantarum (10 9 CFU / g: Lactobacillus reuteri (10 9 CFU / g: Lactobacillus paracasei (10 9 CFU / g): Streptococcus thermophilus (10 9 CFU / g): Lactobacillus bulgaricus (10 9 CFU / g)=1:3:2:1:1 mass ratio for inoculation, and the inoculum volume is 0.35g / 100mL;

[0039] (7) Fermentation: The inoculated fermentation bottle was placed in a constant temperature incubator at 37° C. for 10 hours, during which the fermentation status was regularly observed;

[0040] (8) Low-temperature ripening: The product is transferred to a 4°C to 6°C environment for refrigerated ripening for 12 to 24 hours to further promote the fusion of flavor substances, improve product taste, and enhance overall quality stability.

[0041] Comparative Example 1

[0042] A method for preparing oat-based fermented milk:

[0043] (1) Raw material selection: Select oatmeal with full grains, pure color and no odor for washing;

[0044] (2) Steaming: Steam the washed oatmeal for 20 min;

[0045] (3) grinding: the oatmeal after cooking is put into a juicer for beating, the beating material-liquid ratio is 1:10 (g:mL), 3g / 100mL of edible oil is added, the beating time is 18min, and after beating, the oatmeal is filtered through a 100-200 mesh gauze;

[0046] (4) Adding main ingredients and supplementary ingredients: Add 100 mL of oat pulp and 9 g / 100 mL of white sugar to the fermentation bottle and stir evenly to fully dissolve the white sugar;

[0047] (5) Sterilization: Seal the fermentation bottle and sterilize it in a 90°C water bath for 20 min;

[0048] (6) Low-temperature ripening: Transfer the product to a 4°C to 6°C environment and refrigerate for 12 to 24 hours.

[0049] The oat-based fermented milk prepared in Example 1 and Comparative Example 1 was subjected to quality assessment. The results are shown in Tables 1-3 and Figure 1 shown.

[0050] Table 1 Changes in free amino acid content of oat milk before and after fermentation

[0051]

[0052] Table 2 Volatile substances and relative contents of examples

[0053]

[0054] Table 3 Comparative Examples Volatile substances and relative contents

[0055]

[0056] Comparing the changes in the free amino acid content of oat milk before and after fermentation (Table 1), it is found that the types of bitter amino acids in the oat milk are reduced after fermentation, which helps to improve the taste of fermented milk and make the flavor of oat fermented milk more harmonious. At the same time, the content of aromatic amino acids is significantly increased, which enhances the flavor level of fermented milk. The floral and fruity aroma components produced can complement the sour taste of acidic substances, making the sour taste softer and fresher.

[0057] Two organic acids were detected in oat milk before and after fermentation ( Figure 1 ), fumaric acid and oxalic acid before fermentation, and lactic acid and oxalic acid after fermentation. A large amount of lactic acid is produced after fermentation, and lactic acid is the main source of sourness in fermented milk. It can reduce the pH value, extend the shelf life of the product, and give the fermented milk a unique flavor. The reduction of oxalic acid and fumaric acid reduces the irritating sour taste, makes the taste softer, and improves the sensory quality.

[0058] After fermentation, the amount of flavor substances in oat milk increases (Table 2, Table 3), making the aroma and taste better and bringing a richer taste. The increase in volatile acids will interact with other flavor components in fermented milk, thereby enriching the flavor level and giving it a relatively long-lasting flavor.

[0059] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For ordinary technical users in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing oat-based fermented milk, characterized in that: The following steps are involved: The oats are steamed and ground, then inoculated with microbial agents, and after fermentation, are post-ripened at low temperature to obtain the oat-based fermented milk.

2. The preparation method according to claim 1, characterized in that: The cooking time is 20 minutes.

3. The preparation method according to claim 1, characterized in that: The grinding conditions are as follows: the solid-liquid ratio is 1:10 (g:mL), 3% edible oil is added, the beating time is 18 minutes, and after the beating is completed, it is filtered through 100-200 mesh gauze.

4. The preparation method according to claim 1, characterized in that: The microbial agent is composed of Lactobacillus plantarum, Lactobacillus reuteri, Lactobacillus paracasei, Streptococcus thermophilus and Lactobacillus bulgaricus in a mass ratio of 1:3:2:1:

1.

5. The preparation method according to claim 1, characterized in that: The fermentation conditions include: adding 9 g / 100 mL of white sugar and 0.35 g / 100 mL of microbial agent to the oat homogenate, and fermenting at 37° C. for 10 hours.

6. The preparation method according to claim 1, characterized in that: The low-temperature ripening conditions are: refrigerated ripening at 4°C to 6°C for 12 to 24 hours.

7. Oat-based fermented milk prepared by the preparation method according to any one of claims 1 to 6.

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