Soybean yoghourt and preparation method thereof

Abstract

The invention discloses soybean yoghurt and a preparation method thereof.The soybean yoghurt is obtained by fermenting raw materials in a formula through a leavening agent, and 100 parts by mass of the formula comprise 70-90 parts by mass of cooked soybean milk, 1-5 parts by mass of a sweetening agent, 0.01-0.02 part by mass of sodium chloride and the balance water; wherein the cooked soybean milk is obtained by grinding soaked soybeans and water according to the mass ratio of 1: 1 and then sequentially braising, filtering and separating. The cooked soybean milk subjected to special treatment is adopted as the raw material, the pure soybean-based soybean yoghurt which is free of beany flavor and retains rich soybean flavor can be obtained without adding a large amount of milk products and fruit juice or fruit granules, and the soybean yoghurt has the advantages of low calorie, high protein and low fat through detection, and is suitable for large-scale production. The healthy and nutritional diet requirements of the current society are met; moreover, the components are simple, are all beneficial to health, and belong to green healthy food.

Description

Technical Field

[0001] The present invention relates to a soy yogurt and a preparation method thereof, belonging to the technical field of food. Background Art

[0002] Yogurt, also known as sour milk or fermented milk, is a dairy product that uses milk, milk powder, and white sugar as the main raw materials. After pasteurization, beneficial bacteria (starter cultures) are added, and after fermentation, it is cooled and filled. Yogurt is rich in nutrients, easy to digest and absorb, can improve human immunity, has good health care effects on the human body, and is sweet and sour, so it has become a favorite dairy product in people's lives.

[0003] Soybeans are rich in nutritional value, containing rich high-quality protein and various essential amino acids required by the human body. Soybean protein belongs to complete protein; moreover, soybeans do not contain cholesterol, only contain stigmasterol, and stigmasterol has the nutritional effects of reducing human serum cholesterol, preventing cerebral hemorrhage, and arteriosclerosis; in addition, soybeans also contain nutrients such as vitamin E, saponins, soybean lecithin, linoleic acid, and linolenic acid, which have strong antioxidant effects, can inhibit the formation of skin spots, have anti-inflammatory and anti-allergic effects, and can also promote fat metabolism, prevent fat accumulation, and have nutritional effects such as softening blood vessels, stabilizing blood pressure, preventing arteriosclerosis, and preventing obesity; in addition, soybeans do not contain lactose, while milk contains lactose, and lactose can only be absorbed by the human body under the action of lactase, but most adults in China lack lactase and suffer from "lactose intolerance", which is also the main reason why most people have diarrhea when drinking milk.

[0004] However, due to the influence of the beany flavor in soybeans, the acceptance of some consumers for soy products and soy dairy products is relatively low. As a result, most current soy yogurts or soy milk drinks still rely on adding a large amount of dairy products and fruit juices or fruit grains to improve the taste and flavor, and pure soy-based yogurts still cannot meet the market demand in terms of flavor and texture.

[0005] In addition, the fat content in whole milk is relatively high, and whole-fat yogurt is likely to cause obesity after being consumed. Although the fat content in skim milk is low, the rich flavor of milk comes from the fat content, so the taste of skim yogurt is relatively poor; in addition, the elderly population needs low-sugar or sugar-free yogurt; therefore, in order to meet the healthy and nutritional dietary needs of the general public, the development of healthy yogurt products with low fat, low sugar or sugar-free, and high protein has become the current research topic. In particular, if a soy yogurt that suits the traditional taste of Chinese people, has a good taste, rich fragrance, high protein, low fat, and green and healthy advantages can be developed, it not only meets the current social needs for healthy and nutritional diets, but also has far-reaching significance for expanding the application of soybeans. Summary of the Invention

[0006] In view of the above problems and requirements existing in the prior art, the object of the present invention is to provide a pure soybean-based soybean yogurt that meets the current social needs for healthy and nutritious diets, has a strong soybean flavor, is low in fat, low in sugar, and is green and healthy, and a preparation method thereof.

[0007] To achieve the above object of the invention, the technical solution adopted by the present invention is as follows:

[0008] A kind of soybean yogurt is obtained by fermenting the raw materials in the formula with a starter. The formula, based on 100 parts by mass, has the following composition and ratio:

[0009] Cooked soybean milk: 70 - 90 parts by mass;

[0010] Sweetener: 1 - 5 parts by mass;

[0011] Sodium chloride: 0.01 - 0.02 parts by mass;

[0012] The balance is water;

[0013] Among them, the cooked soybean milk is obtained by soaking soybeans and water in a mass ratio of 1:1, grinding them, and then successively carrying out simmering and filtration separation.

[0014] In one embodiment, the simmering means sealing and heating at 135 - 145 °C for 35 - 45 minutes under a pressure of 0.03 - 0.08 MPa.

[0015] In a preferred embodiment, the sweetener is a composition of trehalose and granulated sugar.

[0016] In a further preferred embodiment, the sweetener is a composition of trehalose and granulated sugar in a mass ratio of 7:3.

[0017] In one embodiment, the starter contains Streptococcus thermophilus, Lactobacillus bulgaricus and probiotics.

[0018] In a preferred embodiment, the starter is a composite strain composed of Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus acidophilus and Bifidobacterium longum in a mass ratio of 2:2:1:1.

[0019] The preparation method of the soybean yogurt of the present invention includes the following steps:

[0020] a) Add the sweetener, sodium chloride and water to the cooked soybean milk cooled to room temperature according to the formula, mix evenly, and then successively carry out homogenization treatment and sterilization treatment;

[0021] b) Cool the treatment liquid in step a) to room temperature, then add the starter, stir evenly, seal, and ferment at a constant temperature of 35 - 45 °C for 8 - 10 hours.

[0022] A preferred embodiment is that the homogenization treatment in step a) is carried out in a homogenizer under closed conditions at 55 - 65°C and 20 - 30 MPa for 8 - 12 minutes.

[0023] A preferred embodiment is that the sterilization treatment in step a) refers to ultra-high temperature instantaneous sterilization (UHT) at 135°C - 145°C for 2 - 8 seconds.

[0024] A preferred embodiment is that in step b), the addition amount of the starter is 1 - 5% of the mass of the treatment liquid.

[0025] An embodiment is that the fermentation in step b) is carried out in a yogurt maker.

[0026] An embodiment is that the preparation of the cooked soybean milk includes the following steps:

[0027] ① Soak the soybeans from which impurities have been removed in 2 - 4 times the mass of water until there is no visible hard white core in the bean heart;

[0028] ② After washing the soaked soybeans with water, grind them at room temperature according to the mass ratio of soaked soybeans to water of 1:1 to obtain raw soybean milk;

[0029] ③ Heat the obtained raw soybean milk under closed conditions at a pressure of 0.03 - 0.08 MPa and at 135 - 145°C for 35 - 45 minutes to obtain cooked soybean milk;

[0030] ④ First, carry out extrusion separation treatment on the obtained cooked soybean milk to remove the soybean dregs therein, and then subject the extrusion separation liquid to high-speed centrifugal separation to remove the residues therein. The obtained separated liquid is the cooked soybean milk.

[0031] A preferred embodiment is that in step ④, a filter screen with 80 - 120 meshes is selected for the extrusion separation treatment.

[0032] A preferred embodiment is that in step ④, the speed of centrifugal separation is 3500 - 4500 revolutions per minute.

[0033] Compared with the prior art, the present invention has the following significant beneficial effects:

[0034] The present invention adopts specially treated cooked soybean milk as raw material, which not only realizes that a pure soybean-based soybean yogurt with no beany smell and retaining a strong bean flavor can be obtained without adding a large amount of dairy products and fruit juice or fruit particles, but also the soybean yogurt is tested to have the advantages of low calories, high protein and low fat, which meets the current social healthy and nutritious dietary needs; moreover, the ingredients are simple and all are beneficial to health, and it belongs to green and healthy food; therefore, compared with the prior art, the present invention has significant advancement and promotion and application value. DETAILED DESCRIPTION

[0035] The technical scheme of the present invention is further described in detail and completely below in conjunction with the examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer.

[0036] Example 1

[0037] A soy yogurt is obtained by fermenting raw materials in a formula with a starter, and the formula has the following composition and proportion based on 1000g:

[0038]

[0039] Wherein, the sweetener is a combination of 21g trehalose and 9g white sugar;

[0040] The preparation method of the soy yogurt comprises the following steps:

[0041] 1. Preparation of cooked soy milk

[0042] ① Soak 10 kg of soybeans after impurities are removed in 30 kg of water until there is no visible white hard core in the bean core;

[0043] ② After washing the soaked soybeans with water, grinding the soaked soybeans at room temperature in a mass ratio of 1:1 to water to obtain raw soybean pulp;

[0044] ③ The obtained soybean raw pulp was heated in a sealed manner at 140° C. under a pressure of 0.06 MPa for 40 minutes to obtain soybean cooked pulp;

[0045] ④ The obtained cooked soybean pulp is first subjected to extrusion separation treatment to remove the bean dregs therein, and a 100-mesh filter screen is selected for the extrusion separation treatment. The extruded separation liquid is then subjected to high-speed centrifugal separation (centrifugal separation speed is 4500 rpm) to remove the residue therein. The obtained separation liquid is the cooked soybean milk, which is naturally cooled to room temperature for standby use.

[0046] 2. Preparation of Soy Yogurt

[0047] a) adding sweetener, sodium chloride and water to the cooked soy milk cooled to room temperature according to the above recipe, mixing evenly, sealing and placing in a homogenizer, homogenizing at 60° C. and 25 MPa for 10 minutes, and then placing in a UHT sterilizer for ultra-high temperature instantaneous sterilization (UHT) treatment at 140° C. for 4 seconds;

[0048] b) cooling the treated liquid in step a) to room temperature (25° C.), adding a starter, stirring evenly, sealing and placing in a yogurt machine, and fermenting at a constant temperature of 40° C. for 8 hours; the starter is a composite strain composed of thermophilic Streptococcus, bulgaricus, Lactobacillus acidophilus and bifidobacterium in a mass ratio of 2:2:1:1, and the addition amount is 3% of the mass of the treated liquid;

[0049] c) Aseptically package the finished product and refrigerate after packaging.

[0050] By sampling 200g for inspection, it was found that the soy yogurt prepared in this embodiment had the following quality indicators:

[0051] Serial number Test item Unit Test result Test method 1 Energy kJ / 100g 323 GB 28050-2011 2 Protein g / 100g 2.6 GB 5009.5-2016 First method 3 Fat g / 100g 1.7 GB 5009.6-2016 Second method 4 Carbohydrate g / 100g 12.7 GB 28050-2011 5 Sodium mg / 100g 11 GB 5009.91-2017 First method

[0052] It can be seen from the above test results that the soy yogurt prepared by the embodiment of the present invention has the advantages of low calories, high protein and low fat, and meets the current social demand for healthy and nutritious diet; moreover, the ingredients are simple and all are beneficial to health, and it belongs to green and healthy food; in addition, through naked eye observation, the soy yogurt system is uniform and free of protein particles; after drinking and tasting, it has a smooth taste, no bean smell, retains a strong bean flavor and is sweet but not greasy, and is suitable for consumption by adults.

[0053] Example 2

[0054] The difference between this embodiment and embodiment 1 is that the raw material formula of the soy yogurt has the following composition and proportion based on 1000g:

[0055]

[0056]

[0057] Wherein, the sweetener is a combination of 35g trehalose and 15g white sugar;

[0058] The preparation method of the cooked soy milk and soy yogurt is the same as that described in Example 1;

[0059] Through visual observation, the soybean yogurt system prepared in this embodiment is uniform without protein particles; after tasting, it has a smooth taste, no soybean smell, and retains the soybean fragrance. Since the proportion of cooked soy milk is reduced and the proportion of sweetener is increased compared with Example 1, this soybean yogurt has a thinner and sweeter taste and is suitable for underage children to eat.

[0060] Example 3

[0061] The difference between this embodiment and Example 1 is only that the raw material formula of the soybean yogurt is calculated according to 1000 g and has the following composition and ratio:

[0062]

[0063] Among them, the sweetener is a combination of 7 g of trehalose and 3 g of granulated sugar;

[0064] The preparation methods of the cooked soy milk and the soybean yogurt are the same as those described in Example 1;

[0065] Through visual observation, the soybean yogurt system prepared in this embodiment is uniform without protein particles; after tasting, it has a smooth taste, no soybean smell, retains the soybean fragrance, has a moderate concentration, and is low in sugar, and is suitable for the elderly to eat.

[0066] As can be seen from the above, in the present invention, the raw soy milk is first subjected to sealed simmering at a specific temperature and pressure, and then the soybean dregs are separated. The raw soy milk is sealed and simmered by adopting the principle similar to that of a pressure cooker, which not only effectively overcomes the soybean smell but also retains the strong soybean fragrance; and by first performing sealed simmering and then separating the soybean dregs, the nutrients and cellulose in the soybean dregs can be fully extracted during the sealed simmering; using the cooked soy milk described in the present invention as a raw material to prepare yogurt can not only obtain a pure soybean-based soybean yogurt without adding a large amount of dairy products and fruit juice or fruit particles and without soybean smell and retaining the strong soybean fragrance, but also the soybean yogurt has the advantages of low calories, high protein, and low fat through detection, meeting the current social health and nutritional diet requirements; moreover, the components therein are simple and are all beneficial to health compositions, belonging to green and healthy foods; therefore, compared with the prior art, the present invention has significant progressiveness and application value.

[0067] It should also be noted here that the water described in the present invention is all purified water, such as cooled distilled water; the room temperature described in the present invention refers to the indoor temperature of 20 - 30 °C.

[0068] Finally, it should be pointed out here that the above are only some preferred embodiments of the present invention and should not be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all fall within the protection scope of the present invention.

Claims

1. A soy yogurt is obtained by fermenting the raw materials in the formula with a fermenting agent, and is characterized in that, The formula, calculated based on 100 parts by mass, has the following composition and ratio: Cooked soybean milk: 70 - 90 parts by mass; Sweetener: 1 - 5 parts by mass; Sodium chloride: 0.01 - 0.02 parts by mass; The balance is water; Among them, the cooked soybean milk is obtained by soaking soybeans and water in a mass ratio of 1:1, grinding them, and then successively carrying out simmering and filtration separation.

2. The soy yogurt according to claim 1, wherein: The simmering refers to heating in a closed state at a pressure of 0.03 - 0.08 MPa and a temperature of 135 - 145 °C for 35 - 45 minutes.

3. The soy yogurt according to claim 1, wherein: The sweetener is a composition of trehalose and granulated sugar.

4. The soy yogurt according to claim 1, characterized in that: The starter contains Streptococcus thermophilus, Lactobacillus bulgaricus and probiotics.

5. The preparation method of the soy yogurt according to claim 1, characterized in that, It includes the following steps: a) Add the sweetener, sodium chloride and water to the cooked soybean milk cooled to room temperature according to the formula. After mixing evenly, carry out homogenization treatment and sterilization treatment successively; b) Cool the treatment liquid in step a) to room temperature, then add the starter, stir evenly and seal, and carry out constant temperature fermentation at 35 - 45 °C for 8 - 10 hours.

6. The preparation method according to claim 5, wherein: The homogenization treatment in step a) is carried out in a homogenizer at a temperature of 55 - 65 °C and a pressure of 20 - 30 MPa for 8 - 12 minutes in a closed state.

7. The preparation method according to claim 5, characterized in that: The sterilization treatment in step a) refers to carrying out ultra-high temperature instantaneous sterilization treatment at 135 °C - 145 °C for 2 - 8 seconds.

8. The preparation method according to claim 5, characterized in that: In step b), the addition amount of the starter is 1 - 5% of the mass of the treatment liquid.

9. The preparation method according to claim 5, characterized in that, The preparation of the cooked soybean milk includes the following steps: ① Soak the soybeans with impurities removed in 2 - 4 times the mass of water until there is no visible white hard core in the bean heart; ② After washing the soaked soybeans with water, carry out grinding at room temperature according to the mass ratio of soaked soybeans to water of 1:1 to obtain raw soybean milk; ③ Heat the obtained raw soybean milk in a closed state at a pressure of 0.03 - 0.08 MPa and a temperature of 135 - 145 °C for 35 - 45 minutes to obtain cooked soybean milk; ④ First carry out extrusion separation treatment on the obtained cooked soybean milk to remove the soybean dregs therein, and then subject the extrusion separation liquid to high-speed centrifugal separation to remove the residues therein. The obtained separated liquid is the cooked soybean milk.

10. The preparation method according to claim 9, characterized in that: In step ④, a filter screen with 80 - 120 meshes is selected for the extrusion separation treatment; the speed for centrifugal separation is 3500 - 4500 revolutions per minute.

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