Preparation method and application of fermented douchi

Abstract

The present application relates to the technical field of fermented soybean, and particularly relates to a preparation method and application of fermented soybean. The fermented soybean is prepared by the following processes: soaking soybeans, steaming three times, combined enzymolysis of natto kinase and acid protease, combined fermentation of Aspergillus oryzae CICC 2082, Aspergillus flavus CICC 2387 and Lactobacillus plantarum CICC 22698, and drying. The fermented soybean has high content of amino acid nitrogen, low content of histamine and high soybean flavor score. The fermented soybean prepared by the present application is rich in nutrients, beneficial to human health, has good flavor and fragrance, and has good soybean flavor and good use experience.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fermented soybean, and particularly relates to a preparation method and application of fermented soybean. BACKGROUND

[0002] Soybean is a traditional fermented soybean product in China, which is made of soybeans or beans after steaming and fermentation. There are many types of soybean, which are divided into black soybean and yellow soybean according to the processing raw materials, and divided into salty soybean and light soybean according to the taste. Soybean has rich nutritional value and various health benefits; the microorganism fermentation process in soybean produces various digestive enzymes, which helps to decompose food and promote digestion; the unique flavor of soybean can stimulate taste buds and increase appetite, especially suitable for people with poor appetite; soybean is a nutritious food with rich protein, vitamins and minerals; the antioxidant substances in soybean can help resist free radicals.

[0003] During the preparation of soybean, histamine and other components that are not conducive to human health are produced, and the quality and flavor of soybean prepared by different preparation processes are uneven. Therefore, it is one of the technical problems to be solved to provide a soybean with stable quality, which is beneficial to human health, rich in flavor and nutrition. SUMMARY

[0004] The present application is directed to the above technical problems, and the technical solution of the present application is provided, which includes a preparation method and application of fermented soybean.

[0005] In one aspect, the present application provides a preparation method of fermented soybean, which comprises the following steps:

[0006] (1) soaking beans in water, draining, first steam treatment with water vapor, cooling, to obtain steamed beans;

[0007] (2) mixing the steamed beans with water and protease, and enzymolysis to obtain an enzymatic product;

[0008] (3) second steam treatment with water vapor for the enzymatic product, cooling, to obtain second steamed beans, then spraying fermentation bacteria liquid, and fermentation to obtain a fermentation product;

[0009] (4) third steam treatment with water vapor for the fermentation product, taking out, drying, to obtain the fermented soybean.

[0010] Preferably, in step (1), the beans include soybeans and / or black beans.

[0011] Preferably, in step (1), water is added to soak the beans.

[0012] Preferably, in step (1), the soaking is room temperature soaking for 3-10 hours.

[0013] Preferably, in step (1), the first steam cooking time is 0.1-2 hours.

[0014] Preferably, in step (2), the mass ratio of the steamed beans to water is 1:0.1-0.3.

[0015] Preferably, in step (2), the protease is nattokinase and acid protease.

[0016] Preferably, in step (2), the amount of nattokinase and acid protease is 40-100 U / g steamed beans and 30-80 U / g steamed beans, respectively.

[0017] Preferably, in step (2), the enzymolysis time is 3-6 hours and the temperature is 40-60℃.

[0018] Preferably, in step (3), the second steam cooking time is 0.1-1.2 hours.

[0019] Preferably, in step (3), the fermentation bacteria liquid is 1-10% of the mass of the second steamed beans.

[0020] Preferably, in step (3), the fermentation bacteria include Aspergillus oryzae CICC 2082, Aspergillus flavus CICC 2387 and Lactobacillus plantarum CICC 22698.

[0021] Preferably, in step (3), the amount of Aspergillus oryzae CICC 2082, Aspergillus flavus CICC 2387 and Lactobacillus plantarum CICC 22698 in the fermentation bacteria is (6.5-9.2)×10 6 cfu / g second steamed beans.

[0022] Preferably, in step (3), the amount ratio of Aspergillus flavus CICC 2387 to Lactobacillus plantarum CICC 22698 in the fermentation bacteria is 2-4:1.

[0023] Preferably, in step (3), the fermentation temperature is 22-30℃ and the time is 12-30 days.

[0024] Preferably, in step (4), the third steam cooking time is 0.1-1 hour.

[0025] Preferably, in step (4), the drying temperature is 60-80℃.

[0026] The application also provides fermented douchi prepared according to the preparation method.

[0027] The application also provides the use of the fermented douchi in food.

[0028] The application has the following advantages:

[0029] The present application adopts beans to be soaked, three times of steaming, combined enzymolysis of natto kinase and acid protease, combined fermentation of Aspergillus oryzae CICC 2082, Aspergillus flavus CICC 2387 and Lactobacillus plantarum CICC 22698, drying and other processes to prepare fermented douchi.

[0030] The douchi prepared by the present application has high content of amino acid nitrogen, low content of histamine and higher douchi aroma score; the douchi prepared by the present application has good nutritional effect and is beneficial to human health, and also has good aroma flavor, sufficient douchi aroma and good use experience.

[0031] The douchi prepared by the present application has high content of amino acid nitrogen up to 9.52 ‰, low content of histamine up to 1.37 mg / kg and total aroma score up to 97.

[0032] The present application uses natto kinase combined with acid protease for enzymolysis, which can promote each other to improve the nitrogen content of douchi and reduce the content of histamine, and give douchi better nutrition, health and aroma effect. The present application uses natto kinase combined with acid protease for enzymolysis, which has better effect than other enzymes such as bromelain.

[0033] The present application uses fermentation process to significantly improve the nutritional effect of douchi, so that the nutritional ingredients of douchi are better decomposed into ingredients beneficial to absorption.

[0034] The present application uses specific fermentation bacteria Aspergillus oryzae CICC 2082, Aspergillus flavus CICC 2387 and Lactobacillus plantarum CICC 22698 for fermentation, which has better effect of improving the quality of douchi than other bacteria. And the combination of Aspergillus flavus CICC 2387 and Lactobacillus plantarum CICC 22698 in the fermentation bacteria can synergistically improve the content of amino acids in douchi and reduce the content of histamine. When the ratio of the two is 0.8-1.2:1, the douchi obtained has better effect.

[0035] The preparation process of the present application is simple, and the douchi prepared has excellent quality and is beneficial to human health, which has good application prospect. DETAILED DESCRIPTION

[0036] The following will be combined with specific embodiments to explain the present application, and the various effects of the present application will be more clearly presented. Those skilled in the art should understand that these specific embodiments are used to illustrate the present application, not to limit the present application.

[0037] Aspergillus oryzae CICC 2082, Aspergillus flavus CICC 2387, Lactobacillus plantarum CICC 22698, Aspergillus niger CICC 40404 and Bacillus subtilis CICC 10262: purchased from China Industrial Microbial Strain Preservation and Management Center

[0038] I. Preparing fermented soybean

[0039] Fermented soybean 1

[0040] (1) Soaking black beans in water until the black beans are submerged, and soaking at room temperature for 6 hours, draining, and first-time steam cooking for 0.4 hours (steam temperature 115°C), and cooling to room temperature to obtain steamed beans;

[0041] (2) Mixing the steamed beans with water (mass ratio of 1:0.2) and protease, and enzymolysis at 50°C for 4.5 hours to obtain an enzymolysis product; wherein the protease is natto kinase and acid protease, and the amount of natto kinase and acid protease is 60 U / g steamed beans and 40 U / g steamed beans, respectively;

[0042] (3) Second-time steam cooking the enzymolysis product for 0.2 hours (steam temperature 115°C), and cooling to room temperature to obtain second-time steamed beans, and then spraying fermentation bacteria liquid, and anaerobic fermentation at 28°C for 22 days to obtain a fermentation product;

[0043] wherein the fermentation bacteria liquid comprises water and fermentation bacteria, the fermentation bacteria liquid is 2% of the mass of the second-time steamed beans, and the fermentation bacteria is Aspergillus oryzae CICC 2082, Aspergillus flavus CICC 2387, and Lactobacillus plantarum CICC 22698;

[0044] When spraying the fermentation bacteria liquid, the amount of Aspergillus oryzae CICC 2082 is 7.8 x 10 6 cfu / g second-time steamed beans; the amount of Aspergillus flavus CICC 2387 is 8.1 x 10 6 cfu / g second-time steamed beans, and the amount of Lactobacillus plantarum CICC 22698 is 8.1 x 10 6 cfu / g second-time steamed beans;

[0045] The amount ratio of Aspergillus flavus CICC 2387 and Lactobacillus plantarum CICC 22698 is 1:1;

[0046] (4) Third-time steam cooking the fermentation product for 0.15 hours (steam temperature 115°C), taking out, and drying at 75°C until the water content is 17.35%, to obtain the fermented soybean.

[0047] Fermented soybean 2

[0048] (1) Soaking black beans in water until the black beans are submerged, and soaking at room temperature for 6.5 hours, draining, and first-time steam cooking for 0.4 hours (steam temperature 115°C), and cooling to room temperature to obtain steamed beans;

[0049] (2), the steamed beans and water (both mass ratio is 1:0.18), the protease is mixed evenly, 48℃ enzyme 4.2 hours, obtain the enzyme solution;Wherein, the protease is natto kinase and acid protease, and the amount of natto kinase and acid protease is 70u / g steamed beans and 30u / g steamed beans respectively;

[0050] (3), the enzyme solution is secondly steamed by water vapor for 0.2 hours (steam temperature 115℃), and cooled to room temperature, to obtain the second steamed beans, then spray fermentation bacteria liquid, 27℃ sealed anaerobic fermentation 25 days, to obtain the fermentation product;

[0051] Wherein, the fermentation bacteria liquid comprises water and fermentation bacteria, the fermentation bacteria liquid is 2% of the mass of the second steamed beans, and the fermentation bacteria is aspergillus oryzae CICC 2082, aspergillus flavus CICC 2387 and lactobacillus plantarum CICC 22698;

[0052] When spraying the fermentation bacteria liquid, the amount of aspergillus oryzae CICC 2082 is 8×10 6 cfu / g second steamed beans;The amount of aspergillus flavus CICC 2387 is 8.7×10 6 cfu / g second steamed beans, and the amount of lactobacillus plantarum CICC 22698 is 7.3×10 6 cfu / g second steamed beans;

[0053] The amount ratio of aspergillus flavus CICC 2387 and lactobacillus plantarum CICC 22698 is 1.19:1;

[0054] (4), the fermentation product is thirdly steamed by water vapor for 0.15 hours (steam temperature 115℃), taken out, dried at 72℃ until the water content is 17.19%, to obtain the fermented douchi.

[0055] Douchi 3:

[0056] Step (2) is: the steamed beans and water (both mass ratio is 1:0.2), the protease is mixed evenly, 50℃ enzyme 4.5 hours, to obtain the enzyme solution;Wherein, the protease is natto kinase, and the amount of natto kinase is 100u / g steamed beans. Others are the same as douchi 1.

[0057] Douchi 4:

[0058] Step (2) is: the steamed beans and water (both mass ratio is 1:0.2), the protease is mixed evenly, 50℃ enzyme 4.5 hours, to obtain the enzyme solution;Wherein, the protease is acid protease, and the amount of acid protease is 100u / g steamed beans. Others are the same as douchi 1.

[0059] Douchi 5:

[0060] Step (2) is: steaming beans and water (mass ratio of 1:0.2), uniformly mixed with protease, enzymolysis at 50℃ for 4.5 hours to obtain an enzymolysis product; wherein the protease is natto kinase and bromelain, and the amount of natto kinase and bromelain is 60 U / g steamed beans and 40 U / g steamed beans, respectively. The others are the same as those of douchi 1.

[0061] Douchi 6:

[0062] Step (3) is: the enzymolysis product is secondly steamed with water vapor for 0.2 hours (steam temperature 115℃), cooled to room temperature to obtain secondly steamed beans, then sprayed with water (2% of the mass of the secondly steamed beans), sealed at 28℃ for 22 days to obtain an intermediate product. The others are the same as those of douchi 1.

[0063] Douchi 7:

[0064] In step (4), the fermentation bacteria are Aspergillus oryzae CICC 2082 and Aspergillus flavus CICC 2387; when spraying the fermentation bacteria liquid, the amount of Aspergillus oryzae CICC 2082 is 7.8×10 6 cfu / g of the secondly steamed beans; the amount of Aspergillus flavus CICC 2387 is 16.2×10 6 cfu / g of the secondly steamed beans. The others are the same as those of douchi 1.

[0065] Douchi 8:

[0066] In step (4), the fermentation bacteria are Aspergillus oryzae CICC 2082 and Aspergillus flavus CICC 2387; when spraying the fermentation bacteria liquid, the amount of Aspergillus oryzae CICC 2082 is 7.8×10 6 cfu / g of the secondly steamed beans; the amount of Aspergillus flavus CICC 2387 is 16.2×10 6 cfu / g of the secondly steamed beans. The others are the same as those of douchi 1.

[0067] Douchi 9:

[0068] In step (4), when spraying the fermentation bacteria liquid, the amount of Aspergillus oryzae CICC 2082 is 7.8×10 6 cfu / g of the secondly steamed beans; the amount of Aspergillus flavus CICC 2387 is 5.4×10 6 cfu / g of the secondly steamed beans, the amount of Aspergillus flavus CICC 2387 and Aspergillus flavus CICC 2387 is 10.8×10 6 cfu / g of the secondly steamed beans; the amount ratio of Aspergillus flavus CICC 2387 and Aspergillus flavus CICC 2387 is 0.5:1. The others are the same as those of douchi 1.

[0069] Douchi 10:

[0070] In step (4), when spraying the fermentation bacteria liquid, the dosage of Aspergillus oryzae CICC 2082 is 7.8 x 10 6 cfu / g of the second steamed beans; the dosage of Aspergillus flavus CICC 2387 is 10.8 x 10 6 cfu / g of the second steamed beans; the dosage of Plantarum CICC 22698 is 5.4 x 10 6 cfu / g of the second steamed beans; the ratio of the dosages of Aspergillus flavus CICC 2387 and Plantarum CICC 22698 is 2:1. Other conditions are the same as those of Douchi 1.

[0071] Douchi 11:

[0072] In step (4), when spraying the fermentation bacteria liquid, the fermentation bacteria are Aspergillus niger CICC 40404 and Bacillus subtilis CICC 10262; the dosage of Aspergillus niger CICC 40404 is 7.8 x 10 6 cfu / g of the second steamed beans; the dosage of Bacillus subtilis CICC 10262 is 16.2 x 10 6 cfu / g of the second steamed beans. Other conditions are the same as those of Douchi 1.

[0073] II. Test Douchi

[0074] Test items are as follows:

[0075] 1. Test the content of amino acid nitrogen and histamine in the douchi. The amino acid nitrogen affects the flavor and nutritional effect of the douchi; the histamine is a harmful component and is used for representing the health performance of the douchi prepared by the application. The content of the amino acid nitrogen is tested according to the method specified in the national standard GB 5009.235-2016, and the unit is ‰. The content of the histamine is tested according to the high performance liquid-triple quadrupole mass spectrometry quantitative detection, and the unit is mg / Kg.

[0076] 2. The aroma of the douchi is evaluated by artificial scoring. Specifically, 10 volunteers aged 30-40 years old (5 males and 5 females) are recruited, each of which scores the aroma of the douchi prepared in each group; the highest score of a single person for a single douchi is 10 points, and the lowest score is 0 point, and then the total score of each douchi is counted.

[0077] The test results are shown in Table 1, wherein " / " in Table 1 represents that no test is performed.

[0078] Table 1: Test of the contents of amino acid nitrogen and histamine and the aroma of douchi

[0079] No. Amino acid nitrogen content / ‰ Histamine content / mg / kg Total score of Douchi flavor Douchi 1 9.52 1.37 97 Douchi 2 9.36 1.48 95 Douchi 3 9.07 1.62 94 Douchi 4 8.91 1.75 93 Douchi 5 8.83 1.81 91 Douchi 6 2.34 / 52 Douchi 7 8.65 3.03 87 Douchi 8 8.71 2.87 89 Douchi 9 9.13 2.12 93 Douchi 10 9.27 1.94 94 Douchi 11 8.29 4.58 80

[0080] It is known through tests that the prepared douchi has high content of amino acid nitrogen, low content of histamine and higher douchi flavor score; the prepared douchi has better nutritional effect, is beneficial to human health, also has better flavor and fragrance, sufficient douchi fragrance and better use experience.

[0081] The prepared douchi has high content of amino acid nitrogen of 9.52 ‰, low content of histamine of 1.37 mg / kg and total flavor score of 97.

[0082] According to the test results of douchi 1, 3-5, it is known that the use of natto kinase and acid protease for enzymolysis can promote the nitrogen content of douchi and reduce the content of histamine, and give douchi better nutrition, health and flavor effect.

[0083] According to the test results of douchi 1, 6, it is known that the use of the fermentation process can significantly improve the nutritional effect of douchi, so that the nutritional ingredients of douchi are better decomposed into ingredients beneficial to absorption.

[0084] According to the test results of douchi 1, 7-11, it is known that the use of specific fermentation bacteria Aspergillus oryzae CICC 2082, Aspergillus flavus CICC 2387 and Lactobacillus plantarum CICC 22698 for fermentation has better effect of improving the quality of douchi compared with other bacteria.

[0085] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A method for preparing fermented tempeh, characterized by, The method comprises the following steps: (1) soaking beans in water, draining, steaming the beans with water vapor for 0.1-2 hours, cooling, and obtaining steamed beans; (2) mixing the steamed beans with water and protease, and enzymatically digesting the mixture at 40-60℃ for 3-6 hours to obtain an enzymatic digest; (3) steaming the enzymatic digest with water vapor for 0.1-1.2 hours, cooling, and obtaining second steamed beans, then spraying the second steamed beans with fermentation bacteria liquid, and fermenting the second steamed beans at 22-30℃ for 12-30 days to obtain a fermentation product; (4) steaming the fermentation product with water vapor for 0.1-1 hours, taking out the fermentation product, and drying the fermentation product to obtain the fermented douchi; The beans include soybeans and / or black beans. In step (2), the protease is nattokinase and acid protease, and the amount of nattokinase and acid protease is 40-100 U / g steamed beans and 30-80 U / g steamed beans, respectively. In step (3), the fermenting bacteria include Aspergillus oryzae CICC 2082, Aspergillus flavus CICC 2387 and Bacillus velezensis CICC 22698, and the amount of each of the three in the fermenting bacteria is (6.5-9.2) x 10 6 cfu / g of the second steamed legumes, and the ratio of the amount of Aspergillus flavus CICC 2387 to the amount of Bacillus velezensis CICC 22698 in the fermenting bacteria is 0.8-1.2:

1.

2. The production method according to claim 1, characterized by, The soaking is room temperature soaking for 3-10 hours.

3. The preparation method according to claim 1, characterized in that, In step (2), the mass ratio of the steamed beans to water is 1:0.1-0.

3.

4. A fermented douchi prepared by the preparation method according to any one of claims 1-3.

5. Use of the fermented douchi according to claim 4 in food.