阅读说明：本技术 一种嫩豆腐及其加工方法 (Tender bean curd and processing method thereof ) 是由 周李波 袁华宾 于 2021-09-08 设计创作，主要内容包括：本发明提出了一种嫩豆腐及其加工方法,属于豆制品加工技术领域,包括：将大豆脱毒、洗净、粉碎后浸泡,磨成豆浆,离心分离,滤液中加入氯化钙,静置,待固化后,沥干水分,得到嫩豆腐。本发明采用化学蒸汽法脱除了大豆中的抗营养因子,包括胰蛋白酶抑制剂、豆腥味成分等,同时在离心后得到的乳化的豆浆液中加入固化剂和破乳剂氯化钙,能有效起到破乳脱泡的效果,也能够使得豆浆快速固化形成豆腐,得到的豆腐口感细腻,保质期久,受到广泛的喜爱。(The invention provides a soft bean curd and a processing method thereof, belonging to the technical field of bean product processing and comprising the following steps: detoxifying soybean, cleaning, pulverizing, soaking, grinding into soybean milk, centrifuging, adding calcium chloride into the filtrate, standing, solidifying, and draining to obtain tender bean curd. The invention removes anti-nutritional factors in the soybeans by adopting a chemical steam method, wherein the anti-nutritional factors comprise trypsin inhibitor, beany flavor components and the like, and meanwhile, the curing agent and the demulsifier calcium chloride are added into the emulsified soybean milk obtained after centrifugation, so that the demulsification and deaeration effects can be effectively achieved, the soybean milk can be rapidly cured to form the bean curd, and the obtained bean curd has fine taste and long shelf life and is widely favored.)

1. A processing method of soft bean curd is characterized in that soybeans are detoxified, washed, crushed and soaked, ground into soybean milk, centrifugally separated, added with calcium chloride in filtrate, kept stand, solidified and drained to obtain the soft bean curd.

2. The processing method of the soft bean curd according to claim 1, comprising the following steps:

s1, detoxification: cleaning semen glycines, peeling, and performing chemical steam treatment for 1-2 hr to obtain detoxified semen glycines;

s2, cleaning, crushing and soaking: cleaning detoxicated semen glycines, and pulverizing to 100-200 mesh to obtain semen glycines powder; soaking bean flour in water, filtering water, and grinding the soaked bean flour into soybean milk;

s3, centrifugal separation: adding the ground soybean milk into a disc centrifuge for centrifugal dehydration;

s4, demulsification: adding calcium chloride into the centrifuged liquid, and stirring and mixing uniformly;

s5, standing and curing: and (5) standing and solidifying, draining water, and cutting into blocks to obtain the soft bean curd.

3. The method for processing soft bean curd according to claim 2, wherein the temperature of the steam in the chemical steam treatment is 100-110 ℃, and the components of the steam comprise acetic acid, ethanol, triethylamine and water.

4. The processing method of the soft bean curd according to claim 3, wherein the steam is prepared by mixing the following raw materials in percentage by mass: 15-20 wt% of acetic acid, 5-12 wt% of ethanol, 2-5 wt% of triethylamine and the balance of water.

5. The processing method of the soft bean curd according to claim 2, wherein the solid-to-liquid ratio of the bean flour to water is 1 g: 10-50 mL.

6. The processing method of soft bean curd according to claim 2, wherein the centrifugal rotation speed is 2000-5000 r/min.

7. The method for processing soft bean curd according to claim 2, wherein the calcium chloride is added in an amount of 5-10% by mass based on the total mass of the system.

8. The method for processing soft bean curd according to claim 2, wherein the standing time is 2-5 hours.

9. A soft bean curd produced by the method according to any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of bean product processing, in particular to a soft bean curd and a processing method thereof.

Background

The soybean is widely planted all over the world, has rich sources, is rich in various nutrient substances necessary for human bodies, such as protein, amino acid, vitamin and the like, and the food prepared from the soybean is the best food for the body building and strengthening of patients with hypertension, diabetes, obesity and the like. Therefore, the bean products are common food for people to live and are deeply loved by consumers, and at present, the soybeans can be processed into various bean products which are convenient to eat. Among them, bean curd is the most common bean product, which contains abundant vegetable protein, a small amount of carbohydrate and fat, and is highly popular with consumers, and its main kinds are south bean curd, north bean curd and lactone bean curd. The main production process of the existing bean curd is as follows: firstly, pulping, namely preparing soybean into soybean milk; secondly, coagulation forming, namely the soybean milk is coagulated into gel containing a large amount of moisture under the combined action of heat and a coagulant.

On one hand, the nutrition of the soybean prepared into bean curd is influenced by anti-nutritional factors contained in the soybean, and on the other hand, the soybean contains saponin, and the soybean milk has the characteristic of membrane foaming, so a large amount of foams appear occasionally in the pulping process, particularly the processing processes of grinding, boiling, separating and the like, and the existence of the foams not only influences the product quality and the yield, but also brings inconvenience to the production operation process. Therefore, the elimination control of foam has become an indispensable link in the production process of bean curd. Since the formation of foam is related to the contact between soymilk and air, there are studies in the prior art on a physical defoaming method for producing soymilk by controlling the contact between air and soymilk, for example, chinese patent application No. 88105154.3 discloses a physical defoaming method in the production of soymilk. However, because the physical defoaming method has poor mechanical practicability and high requirements for operators, the defoaming agent is usually added in the prior art to eliminate the foam generated in the bean product processing process.

For example, chinese patent 201610780735.X discloses a method for preparing bean curd without additives, wherein the production process of bean curd comprises the following steps: the production method comprises the steps of preparing raw materials- > cleaning- > soaking- > grinding- > boiling slurry- > filtering- > coagulating slurry- > squatting brain- > spreading cloth- > casting- > finishing- > squeezing- > finished products by using biological enzyme, and in the application, the defoaming agent is added into slurry in the slurry boiling process, so that the generation of foam can be reduced to a certain extent, and the quality of the obtained bean curd product is improved. However, most of the existing antifoaming agents for bean curd processing are prepared by compounding organic silicone oil (polydimethylsiloxane), tween and span, the requirements of the bean curd preparation process on the antifoaming effect are higher, the antifoaming effect of the existing antifoaming agents is relatively poor, and the antifoaming requirements of bean products are difficult to meet, so that the quality of the obtained bean curd is influenced. Therefore, the conventional bean curd manufacturers generally guarantee the defoaming effect by increasing the amount of the defoaming agent. In the food safety national standard food additive polydimethylsiloxane and emulsion thereof (GB2760), the maximum usage amount of the processing aid polydimethylsiloxane in the production of bean products cannot exceed 0.3g/kg by using amount of each kilogram of soybeans, the conventional common defoaming agent is used in a national standard range and hardly meets the defoaming requirement, and the usage amount is far more than the specified usage amount in the standard.

For another example, the chinese patent application No. 201010196682.X discloses a poultry egg tofu and a preparation method thereof, the poultry egg tofu is prepared by using eggs and soybeans as main raw materials and gluconolactone as a coagulant, wherein the raw materials are in parts by weight as follows: 98-100 parts of soybean, 36-45 parts of egg, 0.3-0.4 part of gluconolactone and 0.2-0.5 part of defoaming agent. The application is that vegetable oil accounting for 0.3-0.5 percent of the soybean mass is put into a container in the grinding and diluting process, 10kg of hot water with the temperature of 50-60 ℃ is added, and the mixture is poured into soybean milk after being stirred, so that the foam in the soybean milk is eliminated, but the defoaming effect is still required to be further improved.

Disclosure of Invention

The invention aims to provide a soft bean curd and a processing method thereof, wherein anti-nutritional factors in soybeans, including trypsin inhibitors, beany flavor components and the like, are removed by adopting a chemical steam method, and meanwhile, a curing agent and a demulsifier calcium chloride are added into emulsified soybean milk obtained after centrifugation, so that the effect of demulsification and deaeration can be effectively achieved, soybean milk can be quickly cured to form bean curd, and the obtained bean curd has fine taste and long shelf life and is widely favored.

The technical scheme of the invention is realized as follows:

the invention provides a processing method of soft bean curd, which comprises the steps of detoxifying, cleaning, crushing and soaking soybeans, grinding into soybean milk, centrifugally separating, adding calcium chloride into filtrate, standing, solidifying, and draining to obtain the soft bean curd.

As a further improvement of the invention, the method specifically comprises the following steps:

s1, detoxification: cleaning semen glycines, peeling, and performing chemical steam treatment for 1-2 hr to obtain detoxified semen glycines;

s2, cleaning, crushing and soaking: cleaning detoxicated semen glycines, and pulverizing to 100-200 mesh to obtain semen glycines powder; soaking bean flour in water, filtering water, and grinding the soaked bean flour into soybean milk;

s3, centrifugal separation: adding the ground soybean milk into a disc centrifuge for centrifugal dehydration;

s4, demulsification: adding calcium chloride into the centrifuged liquid, and stirring and mixing uniformly;

s5, standing and curing: and (5) standing and solidifying, draining water, and cutting into blocks to obtain the soft bean curd.

As a further improvement of the invention, the steam temperature in the chemical steam treatment is 100-110 ℃, and the components of the steam comprise acetic acid, ethanol, triethylamine and water.

As a further improvement of the invention, the steam is prepared by mixing the following raw materials in percentage by mass: 15-20 wt% of acetic acid, 5-12 wt% of ethanol, 2-5 wt% of triethylamine and the balance of water.

As a further improvement of the invention, the solid-to-liquid ratio of the soybean powder to water is 1 g: 10-50 mL.

As a further improvement of the invention, the centrifugal rotating speed is 2000-5000 r/min.

As a further improvement of the invention, the addition amount of the calcium chloride is 5-10% of the total mass of the system.

As a further improvement of the invention, the standing time is 2-5 h.

The invention further protects the soft bean curd prepared by the processing method.

The invention has the following beneficial effects: the invention removes anti-nutritional factors in the soybeans by adopting a chemical steam method, wherein the anti-nutritional factors comprise trypsin inhibitor, beany flavor components and the like, and meanwhile, the curing agent and the demulsifier calcium chloride are added into the emulsified soybean milk obtained after centrifugation, so that the demulsification and deaeration effects can be effectively achieved, the soybean milk can be rapidly cured to form the bean curd, and the obtained bean curd has fine taste and long shelf life and is widely favored.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The method specifically comprises the following steps:

s1, detoxification: cleaning semen glycines, peeling, and performing chemical steam treatment for 1 hr to obtain detoxified semen glycines;

the steam temperature is 100 ℃, and the steam is prepared by mixing the following raw materials in percentage by mass: 15 wt% acetic acid, 5 wt% ethanol and 2 wt% triethylamine, the balance being water.

S2, cleaning, crushing and soaking: cleaning detoxicated semen glycines, and pulverizing to 100 mesh to obtain semen glycines powder; soaking bean flour in water, wherein the solid-to-liquid ratio of the bean flour to the water is 1 g: 10mL, filtering water, and grinding the soaked bean powder into soybean milk;

s3, centrifugal separation: adding the ground soybean milk into a disc centrifuge for centrifugal dehydration, wherein the centrifugal rotation speed is 2000 r/min;

s4, demulsification: adding calcium chloride into the centrifuged liquid, wherein the addition amount of the calcium chloride is 5% of the total mass of the system, and uniformly stirring and mixing;

s5, standing and curing: standing for 2h, solidifying, draining, and cutting to obtain tender bean curd.

Example 2

The method specifically comprises the following steps:

s1, detoxification: cleaning semen glycines, peeling, and performing chemical steam treatment for 2 hr to obtain detoxified semen glycines;

the steam temperature is 110 ℃, and the steam is prepared by mixing the following raw materials in percentage by mass: 20 wt% acetic acid, 12 wt% ethanol and 5 wt% triethylamine, the balance being water.

S2, cleaning, crushing and soaking: cleaning detoxicated semen glycines, and pulverizing to 200 mesh to obtain semen glycines powder; soaking bean flour in water, wherein the solid-to-liquid ratio of the bean flour to the water is 1 g: 50mL, filtering water, and grinding the soaked bean powder into soybean milk;

s3, centrifugal separation: adding the ground soybean milk into a disc centrifuge for centrifugal dehydration, wherein the centrifugal rotation speed is 5000 r/min;

s4, demulsification: adding calcium chloride into the centrifuged liquid, wherein the addition amount of the calcium chloride is 10% of the total mass of the system, and uniformly stirring and mixing;

s5, standing and curing: standing for 2-5h, solidifying, draining, and cutting to obtain tender bean curd.

Example 3

The method specifically comprises the following steps:

s1, detoxification: cleaning semen glycines, peeling, and performing chemical steam treatment for 1.5 hr to obtain detoxified semen glycines;

the steam temperature is 105 ℃, and the steam is prepared by mixing the following raw materials in percentage by mass: 17 wt% acetic acid, 7 wt% ethanol and 3 wt% triethylamine, the balance being water.

S2, cleaning, crushing and soaking: cleaning detoxicated semen glycines, and pulverizing to 150 mesh to obtain semen glycines powder; soaking bean flour in water, wherein the solid-to-liquid ratio of the bean flour to the water is 1 g: 30mL, filtering water, and grinding the soaked bean powder into soybean milk;

s3, centrifugal separation: adding the ground soybean milk into a disc centrifuge for centrifugal dehydration, wherein the centrifugal rotation speed is 3500 r/min;

s4, demulsification: adding calcium chloride into the centrifuged liquid, wherein the addition amount of the calcium chloride is 7 percent of the total mass of the system, and uniformly stirring and mixing;

s5, standing and curing: standing for 3.5h, solidifying, draining, and cutting to obtain tender bean curd.

Test example 1

The shelf life test was performed on examples 1 to 3 of the present invention and commercially available bean curd, and the results are shown in Table 1.

TABLE 1

Group of	Shelf life (Tian)
		Example 1	25
Example 2	27
		Example 3	30
Is commercially available	5

As can be seen from the above table, the shelf life of the soft bean curd prepared according to the present invention is significantly extended.

Test example 2 detection of ingredients of beany flavor

The test object is: examples 1-3 and commercial tofu.

And (4) checking items: a beany flavor component.

The detection method comprises the following steps:

and determining the beany flavor components by adopting HS-SPME-GC-MS. Crushing a soybean sample, and sieving the crushed soybean sample with a 40-mesh sieve to obtain the soybean powder. Placing 2g soybean powder and 3mL deionized water in a headspace bottle, adding 10 μ L p-dichlorobenzene-methanol solution (internal standard substance) with mass concentration of 0.12mg/mL, mixing, water bathing at 50 deg.C for 30min, adsorbing with extraction head for 40min, and desorbing at 250 deg.C for 5 min. GC conditions were as follows: SH-Rxi-5 SiLMS chromatographic column; the temperature raising program is that the temperature is kept for 1min at 50 ℃, is raised to 150 ℃ at 10 ℃/min, is kept for 3min, is raised to 290 ℃ at 8 ℃/min, and is kept for 2 min; the temperature of a sample inlet is 250 ℃; helium is taken as carrier gas, and the flow rate is 1.0 mL/min; adopts a non-shunting sample introduction mode. MS conditions: bombarding an ion source with electrons; an ionization mode EI; ionization voltage 70 eV; the temperature of the electron source is 200 ℃; filament current 150 μ A; scanning a mass range (m/z) of 45-500; the scanning mode is Scan. The results of the experiments were compared with the database of NIST14/NIST14s, and compounds having a degree of similarity of more than 80% were identified as the beany flavor component of the soybean sample, and the content thereof was tested.

And (4) testing results: see table 2.

TABLE 2 Soy bean odor component and content (unit. mu.g/kg)

Group of	Hexanal	Trans-2-hexenal	1-octen-3-ol	N-hexanol	N-pentanol	Benzaldehyde
							Flavor profile	Green grass flavor	Taste of green leaves	Mushroom flavor	Taste of green leaves	Green bean flavor	Bitter apricot kernel flavor
Is commercially available	3256	187	1124	1321	30	9
							Example 1	353	102	242	298	10	4
Example 2	343	98	237	288	9	3
							Example 3	330	95	232	275	7	3

As can be seen from the above table, the beany flavor components of the soft bean curd prepared by the embodiment of the present invention are significantly reduced, which is significantly lower than that of the commercially available bean curd.

Compared with the prior art, the invention removes anti-nutritional factors in the soybeans by adopting a chemical steam method, wherein the anti-nutritional factors comprise trypsin inhibitor, beany flavor components and the like, and meanwhile, the curing agent and the demulsifier calcium chloride are added into the emulsified soybean milk obtained after centrifugation, so that the demulsification and deaeration effects can be effectively achieved, the soybean milk can be rapidly cured to form the bean curd, and the obtained bean curd has fine taste and long shelf life and is widely favored.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.