Method for removing fishy smell of soybean milk through combined treatment of pulsed electric field and vanillic acid

Abstract

The invention discloses a method for removing the fishy smell of soybean milk through combined treatment of a pulsed electric field and vanillic acid, and belongs to the technical field of food processing treatment.The method comprises the steps that soybean milk is placed in the pulsed electric field environment to be treated, then vanillic acid is added, and the soybean milk subjected to fishy smell removal treatment is obtained. According to the method, the soybean milk is treated by utilizing a low-energy-consumption and efficient pulsed electric field, so that protein molecules are promoted to generate polarization effect, secondary bonds of a protein high-grade structure are maintained to be damaged, the protein structure is expanded, and hydrophobic groups are exposed. In addition, vanillic acid is more easily combined with protein hydrophobic groups, and beany flavor functional groups are released due to the fact that the beany flavor functional groups cannot compete for binding sites. The synergistic effect of the pulsed electric field and the vanillic acid is more favorable for removing fishy smell substances in the soybean milk.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, in particular to a method for removing the fishy smell of soybean milk by combining pulse electric field and vanillic acid. Background Art

[0002] Soybean is an important source of plant protein in my country. It has many advantages such as a complete range of amino acids, rich protein content, and balanced nutrition. The high nutritional value of soybean makes it an important raw material for preparing food. At present, soy milk, as the most common bean food, has been widely produced, but its beany smell seriously affects consumers' purchasing desire and limits the development of the soy milk industry. The formation of beany smell is closely related to a series of chemical reactions caused by lipoxygenase and other oxidizing substances during its preparation. There are two main pathways: ① enzymatic reaction (lipoxygenase and lipids in soybean undergo oxidation reaction under oxygen, temperature and other conditions to produce beany smell substances) ② non-enzymatic reaction (unsaturated fatty acids containing unsaturated double bonds in soybeans are easy to react with active oxygen to form hydroperoxides). The main soybean smell substances are volatile substances such as hexanal, heptanal, hexanol, 1-octen-3-ol, and 2-pentylfuran.

[0003] In the prior art, there are three common methods for removing the beany smell of soy milk: 1. Reducing or inhibiting the content of lipoxygenase by chemical (organic solvent extraction, pH adjustment treatment, reducing agent method) or physical (heat treatment, supercritical CO2 extraction, new deodorization technology) methods to reduce the formation of beany smell substances; 2. Adding exogenous substances (antioxidants, enzymes, microorganisms) to promote them to react with beany smell functional groups to generate compounds that are not easy to produce beany smell; 3. Adding exogenous substances (flavors, fragrances, cyclodextrins) to cover or remove the formed beany smell. Method 1 will have a certain degree of chemical reagent residues, and high temperature will also destroy some nutrients; Method 3 has deficiencies in the safety and scope of use of masking materials.

[0004] At present, the method for removing bad flavor from soybean milk is limited to the methods of physics, chemistry and biology, for example, the patent of Chinese patent application number CN109805280A discloses a method for removing the smell of soybeans for soybean milk production, and removes the beany smell by cleaning and soaking, removing the smell of smelling agent (sulfite, gluconolactone), steam heating, fermentation and distillation, but the above-mentioned process is too complicated and time-consuming. Another example is the patent of Chinese patent application number CN117084369A discloses a method for removing the smell of soybeans, and uses the embedding material of cyclodextrin-carboxymethyl cellulose composite as a carrier to soak soybeans, inhibits enzymatic oxidation and absorbs some smelly substances to achieve the effect of removing the smell, but after the treatment, soybean milk will have certain structural changes, reducing its solubility. Another example is the patent of Chinese patent application number CN111011578A discloses a method for removing the smell of soybean protein, which mainly achieves the effect of removing the smell of smell by adding isothiocyanate, but it has a pungent smell. Although the above methods all have a certain degree of fishy removal effect, they have not achieved efficient, safe and natural industrial production and need further improvement.

[0005] In summary, after extensive searching by the applicant, at least the above-mentioned technical problems to be solved urgently exist in this field. Therefore, it is necessary to develop or improve a method for removing the fishy smell of soy milk by combining pulsed electric field and vanillic acid. Summary of the invention

[0006] Based on this, in order to solve one of the problems in the prior art, the present invention provides a method for removing the fishy smell of soy milk by combining pulsed electric field and vanillic acid. The specific technical scheme is as follows:

[0007] A method for removing the fishy smell of soybean milk by combining pulse electric field and vanillic acid, the method comprising the following steps:

[0008] Placing the ground soy milk in a pulse electric field environment for pulse electric field treatment, wherein the intensity of the pulse electric field treatment is 20KV / cm to 30KV / cm, and the pulse time is 400μs to 500μs;

[0009] Add vanillic acid to the soy milk treated with the pulse electric field, and stir magnetically for 25 min to 35 min at a speed of 350 r / min to 550 r / min at 4° C. to 8° C. to obtain deodorized soy milk.

[0010] Furthermore, the pulse intensity is 25KV / cm to 30KV / cm, and the pulse time is 450μs to 500μs.

[0011] Further, the concentration of soy milk is (10g~12g

[0012] ) / 100mL.

[0013] Furthermore, the added amount of the vanillic acid is (30-50) mg / g protein of vanillic acid.

[0014] Furthermore, (40-50) mg / g of vanillic acid was added to the soy milk treated with the pulse electric field, and after mixing, the mixture was magnetically stirred at (6-8)°C for 30-35 min at a speed of 450-550 r / min to obtain a deodorized soy milk solution.

[0015] Furthermore, the preparation steps of soy milk are as follows: fresh soybeans are washed and mixed with water at a mass ratio of 1: (3-5) for 8h-10h; the soaked soybeans are ground for 15min-20min at a mass ratio of 1: (7-9) for 15min-20min, filtered with a (100-120) mesh nylon mesh bag, and boiled at 95℃-100℃ for 10min-15min.

[0016] Furthermore, the preparation steps of soy milk are as follows: fresh soybeans are washed and soaked for 9h to 10h at a soybean-water ratio of 1: (4-5) by mass; the soaked soybeans are ground for 18min to 20min at a soybean-water ratio of 1: (8-9) by mass, filtered using a 100-mesh nylon mesh bag, and boiled at 95° C. for 12min to 15min.

[0017] Compared with the prior art, the beneficial effects include:

[0018] 1. The present invention uses a low-energy, high-efficiency pulsed electric field to treat soybean milk, which causes the protein molecules to polarize, so that the secondary bonds that maintain the higher-level structure of the protein are destroyed, thereby allowing the protein structure to unfold and the hydrophobic groups to be exposed. In addition, vanillic acid is more likely to bind to the hydrophobic groups of proteins, and the beany functional groups are released because they cannot compete for the binding sites. The synergistic effect of the pulsed electric field and vanillic acid is more conducive to removing the fishy substances in soybean milk.

[0019] 2. The present invention utilizes the antioxidant property of vanillic acid to inhibit lipid oxidation in soy milk. The hydrogen atoms contained in vanillic acid can combine with some beany functional groups, thereby eliminating the odor characteristics.

[0020] 3. The process of the present invention is simple, efficient and low in energy consumption, and provides a certain technical reference for removing soybean odor by combining pulse electric field with vanillic acid. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with its embodiments. It should be understood that the specific implementation methods described herein are only used to explain the present invention and do not limit the scope of protection of the present invention.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0023] In one embodiment of the present invention, a method for removing the fishy smell of soybean milk by using a pulsed electric field and vanillic acid combined treatment comprises the following steps:

[0024] Placing the ground soy milk in a pulse electric field environment for pulse electric field treatment, wherein the intensity of the pulse electric field treatment is 20KV / cm to 30KV / cm, and the pulse time is 400μs to 500μs;

[0025] Add vanillic acid to the soy milk treated with the pulse electric field, and stir magnetically for 25 min to 35 min at a speed of 350 r / min to 550 r / min at 4° C. to 8° C. to obtain deodorized soy milk.

[0026] In one of the embodiments, the pulse intensity is 25KV / cm to 30KV / cm, and the pulse time is 450μs to 500μs.

[0027] In one embodiment, the concentration of soy milk is (10g~12g

[0028] ) / 100mL.

[0029] In one embodiment, the added amount of vanillic acid is (30-50) mg / g protein of vanillic acid.

[0030] In one embodiment, (40-50) mg / g vanillic acid is added to the soy milk treated with a pulse electric field, and after mixing, the mixture is magnetically stirred at (6-8)°C for 30-35 min at a speed of 450-550 r / min to obtain a deodorized soy milk solution.

[0031] In one of the embodiments, the preparation steps of soy milk are as follows: fresh soybeans are washed and mixed with water at a mass ratio of 1: (3-5) for 8h-10h; the soaked soybeans are ground for 15min-20min at a mass ratio of 1: (7-9) for 15min-20min, filtered using a (100-120) mesh nylon mesh bag, and boiled at 95℃-100℃ for 10min-15min.

[0032] In one of the embodiments, the preparation steps of soy milk are as follows: fresh soybeans are washed and soaked for 9h to 10h in a soybean-water ratio of 1: (4-5) by mass; the soaked soybeans are ground for 18min to 20min in a soybean-water ratio of 1: (8-9) by mass, filtered using a 100-mesh nylon mesh bag, and boiled at 95°C for 12min to 15min.

[0033] In the above scheme, the pulse electric field is combined with the action of vanillic acid to achieve synergistic effect and has a significant effect on removing the fishy smell of soybeans.

[0034] The embodiments of the present invention will be described in detail below with reference to specific examples.

[0035] Embodiment 1:

[0036] A method for removing the fishy smell of soybean milk by combining pulse electric field and vanillic acid, the method comprising the following steps:

[0037] (1) The preparation steps of soy milk are as follows: 50 g of fresh soybeans are washed and soaked in 150 ml of water for 8 h; the soaked soybeans are ground for 15 min at a soybean-water ratio of 1:7, filtered using a 100-mesh nylon mesh bag, and boiled at 95°C for 10 min.

[0038] (2) Pulsed electric field treatment of soybean milk: 100 ml of 10 g / 100 ml soybean milk solution was poured into a pulse dish and pulsed with an electric field strength of 20 KV / cm and a pulse time of 400 μs;

[0039] (3) Vanillic acid-treated soy milk solution: 30 mg / g protein of vanillic acid was added to the soy milk solution treated with the pulsed electric field, and the mixture was mixed and magnetically stirred at 4° C. for 25 min at a speed of 400 rpm to obtain a deodorized soy milk solution.

[0040] It was determined that the contents of the main odor substances hexanal, heptanal, hexanol, 1-octen-3-ol, and 2-pentylfuran in the soymilk solution of this embodiment decreased by 35.1%, 20.3%, 13.4%, 10.0%, and 3.2%, respectively, compared with the untreated soymilk solution.

[0041] Embodiment 2:

[0042] A method for removing the fishy smell of soybean milk by combining pulse electric field and vanillic acid, the method comprising the following steps:

[0043] (1) The preparation steps of soy milk are as follows: 150 g of fresh soybeans are washed and soaked in 450 ml of water for 9 h; the soaked soybeans are ground for 18 min at a soybean-water ratio of 1:8, filtered using a 100-mesh nylon mesh bag, and boiled at 95°C for 12 min.

[0044] (2) Pulsed electric field treatment of soybean milk: 150 ml of 11 g / 100 ml soybean milk solution was poured into a pulse dish and pulsed with an electric field strength of 25 kV / cm and a pulse time of 450 μs;

[0045] (3) Vanillic acid-treated soy milk solution: 40 mg / g protein of vanillic acid was added to the soy milk solution treated with a pulsed electric field, and the mixture was mixed and magnetically stirred at 6° C. for 30 min at a speed of 450 rpm to obtain a deodorized soy milk solution.

[0046] It was determined that the contents of the main odor substances hexanal, heptanal, hexanol, 1-octen-3-ol, and 2-pentylfuran in the soymilk solution of this embodiment decreased by 40.1%, 25.3%, 18.4%, 16.1%, and 6.2%, respectively, compared with the untreated soymilk solution.

[0047] Embodiment 3:

[0048] A method for removing the fishy smell of soybean milk by combining pulse electric field and vanillic acid, the method comprising the following steps:

[0049] (1) The preparation steps of soy milk are as follows: 200 g of fresh soybeans are washed and soaked in 600 ml of water for 10 h; the soaked soybeans are ground for 20 min at a soybean-water ratio of 1:9, filtered using a 100-mesh nylon mesh bag, and boiled at 95°C for 15 min.

[0050] (2) Pulsed electric field treatment of soybean milk: 200 ml of 12 g / 100 ml soybean milk solution was poured into a pulse dish and pulsed with an electric field strength of 30 KV / cm and a pulse time of 500 μs;

[0051] (3) Vanillic acid-treated soy milk solution: 50 mg / g protein of vanillic acid was added to the soy milk solution treated with the pulsed electric field, and the mixture was mixed and magnetically stirred at 8° C. for 35 min at a rotation speed of 550 rpm to obtain a deodorized soy milk solution.

[0052] It was determined that the contents of the main odor substances hexanal, heptanal, hexanol, 1-octen-3-ol, and 2-pentylfuran in the soymilk solution of this embodiment decreased by 37.3%, 22.4%, 15.3%, 14.4%, and 5.1%, respectively, compared with the untreated soymilk solution.

[0053] Comparative Example 1:

[0054] The difference between Comparative Example 1 and Example 3 is that no pulse electric field treatment is performed in Comparative Example 1, and the rest is the same as Example 3.

[0055] After measurement, the contents of the main odor substances hexanal, heptanal, hexanol, 1-octen-3-ol, and 2-pentylfuran in the soy milk solution in Comparative Example 1 decreased by 13.9%, 6.8%, 3.3%, 2.4%, and 0.4%, respectively, compared with the untreated soy milk solution. Although the odor decreased compared with the untreated soy milk solution, indicating that single vanillic acid also has the effect of removing bean odor, the odor reduction effect is significantly worse than that of Example 3, indicating that the present application has a promoting effect on removing odor substances through the pulsed electric field, and the pulsed electric field interacts with vanillic acid, and the effect of removing the odor is more significant.

[0056] Comparative Example 2:

[0057] The difference between Comparative Example 2 and Example 3 is that vanillic acid is not added in Comparative Example 2, and the rest is the same as Example 3.

[0058] It was determined that the contents of the main odor substances hexanal, heptanal, hexanol, 1-octen-3-ol, and 2-pentylfuran in the soy milk solution of Comparative Example 2 decreased by 21.6%, 13.2%, 9.8%, 6.4%, and 1.9%, respectively, compared with the untreated soy milk solution. This indicates that the pulsed electric field has a positive effect on removing the odor. The single pulsed electric field has a positive effect on removing the odor, but the effect is significantly worse than that of Example 3. This again indicates that the pulsed electric field and vanillic acid in this application have a synergistic effect, achieving an effect of 1+1>2, and can more thoroughly remove the odor substances in soy milk.

[0059] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for removing the fishy smell of soybean milk by combining pulse electric field and vanillic acid, characterized in that: The method comprises the following steps: Placing the ground soy milk in a pulse electric field environment for pulse electric field treatment, wherein the intensity of the pulse electric field treatment is 20KV / cm to 30KV / cm, and the pulse time is 400μs to 500μs; Add vanillic acid to the soy milk treated with the pulse electric field, and stir magnetically for 25 min to 35 min at a speed of 350 r / min to 550 r / min at 4° C. to 8° C. to obtain deodorized soy milk.

2. The method according to claim 1, characterized in that The pulse intensity is 25KV / cm to 30KV / cm, and the pulse time is 450μs to 500μs.

3. The method according to claim 1, characterized in that The concentration of soy milk is (10g~12g) / 100mL.

4. The method according to claim 1, characterized in that: The added amount of the vanillic acid is (30-50) mg / g protein of vanillic acid.

5. The method according to claim 1, characterized in that Add (40-50) mg / g vanillic acid to the soy milk treated with pulse electric field, mix well, and stir magnetically for 30-35 min at (6-8)° C. and 450-550 r / min to obtain a deodorized soy milk solution.

6. The method according to claim 1, characterized in that The preparation steps of soy milk are as follows: fresh soybeans are cleaned, mixed and soaked for 8h to 10h at a mass ratio of soybeans to water of 1: (3-5); the soaked soybeans are ground for 15min to 20min at a mass ratio of soybeans to water of 1: (7-9), filtered using a (100-120) mesh nylon mesh bag, and boiled at 95℃ to 100℃ for 10min to 15min.

7. The method according to claim 1, characterized in that The preparation steps of soy milk are as follows: fresh soybeans are washed and soaked for 9h to 10h at a soybean-water ratio of 1: (4-5) by mass; the soaked soybeans are ground for 18min to 20min at a soybean-water ratio of 1: (8-9) by mass, filtered using a 100-mesh nylon mesh bag, and boiled at 95° C. for 12min to 15min.