A method for modifying soy protein isolate and products and use thereof in ice cream

Abstract

The application discloses a modification method and product of soybean protein isolate and application of the product in ice cream, and comprises the following steps: applying modified soybean protein isolate in preparation of ice cream; and the final product is milky white, rich in various amino acids, free of animal fat, cholesterol and lactose, and has good taste, good tissue state, low melting rate and high expansion rate after freezing, and is good in taste and nutrition.

Description

Technical Field

[0001] This invention belongs to the field of protein modification, specifically relating to a method and product for modifying soy protein isolate and its application in ice cream. Background Technology

[0002] Traditional ice cream is a frozen beverage made primarily from drinking water, milk, milk powder, cream, and sugar, with the addition of appropriate food additives through various processes. As a frozen dairy product, ice cream is characterized by its rich nutrition, smooth texture, intense flavor, and easy digestibility. However, as a high-sugar, high-fat, and high-energy food, excessive consumption can lead to excessive intake of fats and sugars, increasing the risk of obesity, high blood pressure, cardiovascular disease, and other related illnesses, posing a serious threat to consumers' health. Currently, modern diets are increasingly trending towards low-sugar, low-fat, and healthier options. To meet consumer demands, there is an urgent need to develop health-oriented and multi-functional ice creams.

[0003] Plant-based ice cream has a lower calorie content than dairy-based ice cream, making it suitable for consumers with lactose intolerance. Its nutritional and health benefits meet people's needs. Soy protein is a rich and high-quality plant protein with good nutritional value and functional properties. Its protein content is about 40%, and its essential amino acid composition is close to that of animal protein. Its digestibility is close to or exceeds that of animal protein, and its quality is significantly superior to other plant proteins.

[0004] However, many functional properties of soy protein, such as solubility, hydration, emulsification, foaming, gelling, and aggregation, still differ significantly from those of milk protein. When applied to ice cream systems, it suffers from drawbacks such as excessive viscosity and hardness, low overrun, and a beany taste. Summary of the Invention

[0005] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for modifying soy protein isolate.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for modifying soy protein isolate, comprising,

[0008] Soy protein isolate was mixed with water and then treated with a pulsed electric field.

[0009] It is then mixed with a complex protease for enzymatic hydrolysis.

[0010] The modified liquid was collected, the enzyme was inactivated, freeze-dried, and milled to obtain modified soy protein isolate powder.

[0011] As a preferred scheme of the modification method, the preparation method of the soybean protein isolate solution comprises the following steps:

[0012] The soybean protein isolate is mixed with water, stirred at 600 rpm for 2-4 hours at 20-25℃, and then placed at 4℃ for 12 hours to obtain the soybean protein isolate solution.

[0013] As a preferred scheme of the modification method, the pulse electric field treatment has a field strength of 10-50 KV / cm and a pulse time of 200-4000 μs.

[0014] As a preferred scheme of the modification method, the pulse electric field has a field strength of 25-35 KV / cm and a pulse time of 1000-2000 μs.

[0015] As a preferred scheme of the modification method, the pulse electric field treatment time is 10-15 min.

[0016] As a preferred scheme of the modification method, the enzymatic treatment has a papain, alkaline protease, neutral protease, and pepsin in the complex protease with a mass ratio of (20-60):(20-30):(20-30):(20-30), and the complex enzyme is added in an amount of 0.1%-0.9% of the weight of the protein.

[0017] The enzymatic temperature is 30-80℃, and the enzymatic time is 10-60 min.

[0018] As a preferred scheme of the modification method, the papain, alkaline protease, neutral protease, and pepsin in the complex protease have a mass ratio of (40-50):(20-30):(20-30):(20-30), the complex enzyme is added in an amount of 0.4%-0.6% of the weight of the protein, the enzymatic temperature is 50-60℃, and the enzymatic time is 25-35 min.

[0019] As a preferred scheme of the modification method, the inactivated enzyme is in a water bath at 90℃ for 30 seconds, and the freeze-drying conditions are -40--10℃ and a vacuum degree of 13-40 Pa.

[0020] Another object of the present application is to provide a modified soybean protein isolate prepared by the modification method.

[0021] Another object of the present application is to provide the application of the modified modified soybean protein isolate in the preparation of ice cream.

[0022] The present application has the following advantages:

[0023] (1) The present application first proposes to use pulse electric field and complex enzyme hydrolysis in combination to modify soybean protein isolate into a modified protein that can completely replace milk protein in ice cream. At the same time, the defects of traditional methods are avoided, and the limitations of single enzyme hydrolysis are overcome.

[0024] (2) The present application modifies the insoluble protein structure in soybean protein isolate into soluble protein through pulse electric field, changes the structure of the protein, causes the subunit to dissociate, and then complex enzyme hydrolysis has an effect on the function and structure of the protein, reduces the molecular weight of the protein, improves the physicochemical properties of the protein, and thus improves its addition degree in ice cream. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0026] Figure 1 The product diagram of the present application embodiment 1. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned purposes, features and advantages of the present application more apparent and easy to understand, the specific implementation manner of the present application will be described in detail in the following combined with the embodiment of the specification.

[0028] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0029] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an independent or alternative embodiment that excludes other embodiments.

[0030] Protease in the present application embodiment:

[0031] Papain: enzyme activity ≥200000u / g, Henan Wanbang Industry Co., Ltd.;

[0032] Alkaline protease: enzyme activity ≥ 150000 u / g, Hefei Tissue Culture Biotechnology Co., Ltd.

[0033] Neutral protease: ≥100000 u / g, Henan Wanbang Industry Co., Ltd.

[0034] Pepsin: ≥100000 u / g, Luohe Huisen Pharmaceutical Co., Ltd.

[0035] In the present application, the determination of the expansion rate of ice cream (gravimetric method): 20 mL of ice cream slurry and finished product before and after freezing are weighed.

[0036] Expansion rate % = (M1-M2) / M2 x 100%

[0037] M1: mass (g) of 20 mL of ice cream slurry;

[0038] M2: mass (g) of 20 mL of ice cream.

[0039] In the present application, the determination of the melting rate of ice cream: at a constant temperature (36℃), the ice cream is cut into about 50g and placed on a 3mm x 3mm metal screen, and the mass of the melted ice cream after 30min is recorded.

[0040] Melting rate % = mass of melted ice cream / total mass of ice cream x 100%.

[0041] Example 1

[0042] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15min, the PEF field strength was 30KV / cm, and the pulse time was 1500us;

[0043] Then mixed with 0.5% of the mass of the complex protease (the mass ratio of papain, alkaline protease, neutral protease and pepsin was 45:20:20:20), and enzymolysis modification was carried out for 30min, the enzymolysis temperature was 55℃; the enzyme was inactivated in a 90℃ water bath for 30 seconds, and freeze-drying was carried out in a system with a vacuum degree of 13-40Pa at-40--10℃.

[0044] (2) The coconut oil was melted in an oven at 60℃, then mixed in a proportion of 4% of modified isolated soybean protein, 12% of coconut oil, 0.15% of mono and di fatty acid glyceride, 0.07% of diacetyl tartaric acid mono and diglyceride, 0.18% of sucrose ester, 8% of sucrose, 4% of glucose syrup, 2% of glucose-fructose syrup, 0.5% of xanthan gum, 0.1% of carrageenan, 0.1% of carboxymethyl cellulose and 0.2% of essence, heated to 80℃, stirred and sterilized for 20min.

[0045] The above mixed liquid is subjected to high-pressure homogenization under a first pressure of 100 bar and a second pressure of 80 bar, and then is aged at -4°C for 12 hours to obtain a plant-based ice cream liquid.

[0046] The plant-based ice cream liquid is poured into an ice cream freezing and stirring for 30 minutes, and then is hardened at -18°C for 24 hours to obtain a soy protein isolate ice cream. Figure 1 .

[0047] Example 2

[0048] (1) The soy protein isolate solution is placed in a PEF device (pulse extraction instrument) for modification for 15 minutes, the PEF field strength is 25KV / cm, and the pulse time is 1500μs;

[0049] Then mixed with 0.5% of the protease (the mass ratio of papain, alkaline protease, neutral protease, and pepsin is 45:20:20:20) by mass, and enzymatic modification for 30 minutes, the enzymatic temperature is 55°C; inactivated enzyme in 90°C water bath for 30 seconds, and freeze-dried in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0050] (2) The coconut oil is melted in an oven at 60°C, and then mixed with the modified soy protein isolate 4%, coconut oil 12%, mono- and di-glycerides 0.15%, diacetyl tartaric acid esters of mono- and di-glycerides 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% in a ratio, heated and stirred at 80°C for 20 minutes, and sterilized.

[0051] The above mixed liquid is subjected to high-pressure homogenization under a first pressure of 100 bar and a second pressure of 80 bar, and then is aged at -4°C for 12 hours to obtain a plant-based ice cream liquid. The plant-based ice cream liquid is poured into an ice cream freezing and stirring for 30 minutes, and then is hardened at -18°C for 24 hours to obtain a soy protein isolate ice cream.

[0052] Example 3

[0053] (1) The soy protein isolate solution is placed in a PEF device (pulse extraction instrument) for modification for 15 minutes, the PEF field strength is 35KV / cm, and the pulse time is 1500μs;

[0054] Subsequently, 0.5% of the complex protease (mass ratio of papain, alkaline protease, neutral protease, and pepsin is 45:20:20:20) is mixed with the protein mass, and enzymatic modification is performed for 30 min at an enzymatic temperature of 55°C. The enzyme is inactivated in a 90°C water bath for 30 seconds, and freeze-drying is performed in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0055] (2) Coconut oil is melted in an oven at 60°C, and then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of monodiglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% at a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture is subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream material liquid. The plant-based ice cream material liquid is poured into an ice cream freezing and whipping machine, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0056] Example 4

[0057] (1) The soybean protein isolate solution is placed in a PEF device (pulse extraction instrument) for modification for 15 min, with a PEF field strength of 10 KV / cm and a pulse time of 1500 μs.

[0058] Subsequently, 0.5% of the complex protease (mass ratio of papain, alkaline protease, neutral protease, and pepsin is 45:20:20:20) is mixed with the protein mass, and enzymatic modification is performed for 30 min at an enzymatic temperature of 55°C. The enzyme is inactivated in a 90°C water bath for 30 seconds, and freeze-drying is performed in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0059] (2) Coconut oil is melted in an oven at 60°C, and then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of monodiglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% at a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture is subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream material liquid. The plant-based ice cream material liquid is poured into an ice cream freezing and whipping machine, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0060] Example 5

[0061] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 50 KV / cm, and the pulse time was 1500 μs;

[0062] Then, 0.5% of the complex protease (the mass ratio of papain, alkaline protease, neutral protease, and pepsin was 45:20:20:20) was mixed with the protein mass, and enzymatic modification was performed for 30 min at 55°C. The enzyme was inactivated by heating in a 90°C water bath for 30 seconds, and freeze-drying was performed in a system at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0063] (2) The coconut oil was melted in an oven at 60°C, and then mixed with the modified soybean protein isolate at a ratio of 4%, coconut oil at 12%, mono- and di-glycerides at 0.15%, diacetyl tartaric acid esters of mono- and di-glycerides at 0.07%, sucrose esters at 0.18%, sucrose at 8%, glucose syrup at 4%, fructose syrup at 2%, xanthan gum at 0.5%, carrageenan at 0.1%, carboxymethyl cellulose at 0.1%, and essence at 0.2%, heated and stirred at 80°C, and sterilized for 20 min. The above mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream material.

[0064] The plant-based ice cream material was poured into an ice cream freezing and whipping device, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0065] The determination results of Examples 1-5 are shown in Table 1.

[0066] Table 1

[0067]

[0068] As can be seen from Table 1, in the process of modifying the soybean protein isolate into ice cream with high addition of plant protein, when only the field strength of the pulse electric field is changed, the melting rate and the overrun of the ice cream are little affected in the further preferred range of 25-35 KV / cm, the overrun is greatly reduced when the field strength of the pulse electric field is lower than the further preferred 10 KV / cm, and the melting rate is greatly improved when the field strength of the pulse electric field is higher than the further preferred 50 KV / cm.

[0069] Wherein, below the further preferred 10KV / cm field strength, the pulse electric field energy is weakened, the structural modification degree of soybean protein isolate is small, the protein subunit dissociation is not sufficient, leading to lower subsequent enzymolysis degree, thus leading to lower ice cream expansion rate; and for the 50KV / cm field strength higher than the preferred range, the pulse electric field energy is larger, the structural damage to the soybean protein isolate is obvious, the modification degree is too large, leading to the inability to maintain the interface strength of the fat ball in the ice cream, leading to weaker ice cream stability and higher melting rate.

[0070] That is, for the process of modifying soybean protein isolate into high-adding plant protein in ice cream by combining pulse electric field and complex enzyme enzymolysis, there is a further preferred pulse electric field strength range.

[0071] Example 6

[0072] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 32KV / cm, and the pulse time was 1500μs;

[0073] Then mixed with 0.5% of the mass of complex protease (the mass ratio of papain, alkaline protease, neutral protease and pepsin was 45:20:20:20), and enzymolysis modification was performed for 30 min at 55℃. The enzyme was inactivated by water bath at 90℃ for 30 seconds, and freeze-drying was performed in a system at-40 to-10℃ and a vacuum degree of 13 to 40 Pa.

[0074] (2) The coconut oil was melted in an oven at 60℃, then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono and di fatty acid glyceride 0.15%, diacetyl tartaric acid mono and diglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% in proportion, heated at 80℃, stirred and sterilized for 20 min. The above mixture was subjected to high pressure homogenization at a primary pressure of 100bar and a secondary pressure of 80bar, then aged at-4℃ for 12h to obtain a plant-based ice cream material liquid. The plant-based ice cream material liquid was poured into an ice cream freezing and whipping device for 30 min, then hardened at-18℃ for 24h to obtain a soybean protein isolate ice cream.

[0075] Example 7

[0076] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 32KV / cm, and the pulse time was 1000μs;

[0077] Subsequently mixed with 0.5% of the protease by weight of the protein, and enzymatic modification for 30 min at 55°C. Inactivated the enzyme in a 90°C water bath for 30 seconds, and freeze-dried in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0078] (2) Coconut oil was melted in an oven at 60°C, and then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglycerides of fatty acids 0.15%, diacetyl tartaric acid esters of mono-diglycerides 0.07%, sucrose esters 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% at a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0079] Example 8

[0080] (1) The soybean protein isolate solution was modified in a PEF device (pulse extraction instrument) for 15 min at a PEF field strength of 32 KV / cm and a pulse time of 2000 μs.

[0081] Subsequently mixed with 0.5% of the protease by weight of the protein, and enzymatic modification for 30 min at 55°C. Inactivated the enzyme in a 90°C water bath for 30 seconds, and freeze-dried in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0082] (2) Coconut oil was melted in an oven at 60°C, and then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglycerides of fatty acids 0.15%, diacetyl tartaric acid esters of mono-diglycerides 0.07%, sucrose esters 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% at a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream mixture.

[0083] The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0084] Example 9

[0085] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 32 KV / cm, and the pulse time was 500 μs;

[0086] Then mixed with 0.5% of the protease (the mass ratio of papain, alkaline protease, neutral protease, and pepsin was 45:20:20:20) by mass of the protein, and enzymatic modification was performed for 30 min at 55°C. The enzyme was inactivated in a 90°C water bath for 30 seconds, and freeze-drying was performed in a system at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0087] (2) The coconut oil was melted in an oven at 60°C, and then mixed with the modified soybean protein isolate 4%, coconut oil 12%, mono- and di-glycerides 0.15%, diacetyl tartaric acid esters of mono- and di-glycerides 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% in a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream material liquid. The plant-based ice cream material liquid was poured into an ice cream freezing and whipping device, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0088] Example 10

[0089] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 32 KV / cm, and the pulse time was 2500 μs;

[0090] Then mixed with 0.5% of the protease (the mass ratio of papain, alkaline protease, neutral protease, and pepsin was 45:20:20:20) by mass of the protein, and enzymatic modification was performed for 30 min at 55°C. The enzyme was inactivated in a 90°C water bath for 30 seconds, and freeze-drying was performed in a system at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0091] (2) Coconut oil was oven-melted at 60°C, then mixed with modified soybean protein 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of mono-diglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, essence 0.2% at 80°C with stirring and sterilization for 20 min. The above mixture was subjected to high pressure homogenization at a first pressure of 100 bar and a second pressure of 80 bar, then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine for 30 min, then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0092] The determination results of Examples 6-10 are shown in Table 2.

[0093] Table 2

[0094]

[0095]

[0096] As can be seen from Table 2, in the process of modifying soybean protein isolate into high-amount plant protein for ice cream, when only the pulse electric field time is changed, the melting rate and overrun of the ice cream are little affected in the further preferred range of 1000-2000 μs, while in the range of the pulse electric field strength protection of the present application, the overrun is greatly reduced when the pulse time is lower than the further preferred 1000 μs, and the melting rate is greatly increased when the pulse time is higher than the further preferred 2000 μs.

[0097] When the pulse time is lower than the further preferred 1000 μs, the pulse electric field energy is weakened, the modification degree of the structure of the soybean protein isolate is small, and the overrun is low. When the pulse time is higher than the preferred range of 2000 μs, the pulse electric field energy is large, the structure of the soybean protein isolate is obviously destroyed, the modification degree is too large, the interface strength of the fat globules in the ice cream cannot be maintained, the fat network structure of the ice cream is weak, and the melting rate is increased.

[0098] That is, in the process of modifying soybean protein isolate into high-amount plant protein for ice cream by using pulse electric field and complex enzyme hydrolysis, there is a further preferred range of pulse electric field time.

[0099] Comparative Example 1

[0100] (1) The soybean protein isolate solution was modified in a PEF device (pulse extraction instrument) for 15 min, the PEF field strength was 30 KV / cm, and the pulse time was 1500 μs;

[0101] (2) Coconut oil was oven-melted at 60°C, then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of monodiglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, flavor 0.2% at a ratio, heated at 80°C, stirred and sterilized for 20 min. The above mixture was subjected to high pressure homogenization at a first pressure of 100 bar and a second pressure of 80 bar, then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine for 30 min, then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0102] Comparative Example 2

[0103] (1) The soybean protein isolate solution was mixed with 0.5% of a compound protease (papain, alkaline protease, neutral protease, and pepsin at a mass ratio of 45:20:20:20) by weight, and enzymatically modified for 30 min at a temperature of 55°C. The enzyme was inactivated by water bath at 90°C for 30 seconds, and then freeze-dried in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0104] (2) Coconut oil was oven-melted at 60°C, then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of monodiglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, flavor 0.2% at a ratio, heated at 80°C, stirred and sterilized for 20 min. The above mixture was subjected to high pressure homogenization at a first pressure of 100 bar and a second pressure of 80 bar, then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine for 30 min, then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0105] Comparative Example 3

[0106] (1) The soybean protein isolate solution was mixed with 0.5% of a compound protease (papain, alkaline protease, neutral protease, and pepsin at a mass ratio of 45:20:20:20) by weight, and enzymatically modified for 30 min at a temperature of 55°C. The enzyme was inactivated by water bath at 90°C for 30 seconds, and then modified in a PEF device (pulsed electric field device) for 15 min at a field strength of 30 KV / cm and a pulse time of 1500 μs. The sample was then freeze-dried in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0107] (2) Coconut oil was oven-melted at 60°C, then mixed with modified soybean protein 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of mono-diglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, essence 0.2% at 80°C, stirred and sterilized for 20 min. The above mixture was subjected to high pressure homogenization at primary pressure 100 bar and secondary pressure 80 bar, then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine for 30 min, then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0108] The results of Examples 1 and Comparative Examples 1-3 are shown in Table 3.

[0109] Table 3

[0110]

[0111]

[0112] As can be seen from Table 3, in Example 1, the overrun of the ice cream was 60.67 and the melt rate was 52.52% under the combined action of pulsed electric field and complex enzyme hydrolysis, which was higher than the overrun of 70.47% produced by the pulsed electric field treatment alone in Comparative Example 1, because the pulsed electric field did not change the molecular weight of the protein. In Comparative Example 2, without the action of pulsed electric field, the overrun was still low, because the pulsed electric field and complex enzyme hydrolysis had a synergistic effect.

[0113] In Comparative Example 3, the protein was first subjected to complex enzyme hydrolysis and then treated with pulsed electric field, which had a poorer effect than Comparative Example 1, because the pulsed electric field changed the protein structure so that the complex enzyme hydrolysis reached the best effect, and the enzyme hydrolysis was insufficient when the protein treated with pulsed electric field was directly subjected to enzyme hydrolysis, so the effect was smaller.

[0114] Comparative Example 4

[0115] (1) The soybean protein isolate solution was modified in a PEF device (pulsed extraction instrument) for 15 min, with a PEF field strength of 5KV / cm and a pulse time of 1500μs;

[0116] Subsequently, 0.5% of the complex protease (mass ratio of papain, alkaline protease, neutral protease, and pepsin is 45:20:20:20) is mixed with the protein mass, and enzymatic modification is performed for 30 min at an enzymatic temperature of 55°C. The enzyme is inactivated in a 90°C water bath for 30 seconds, and freeze-drying is performed in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0117] (2) Coconut oil is melted in an oven at 60°C, and then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of monodiglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% at a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture is subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture is poured into an ice cream freezing and whipping machine, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0118] Comparative Example 5

[0119] (1) The soybean protein isolate solution is placed in a PEF device (pulse extraction instrument) for modification for 15 min, with a PEF field strength of 70 KV / cm and a pulse time of 1500 μs.

[0120] Subsequently, 0.5% of the complex protease (mass ratio of papain, alkaline protease, neutral protease, and pepsin is 45:20:20:20) is mixed with the protein mass, and enzymatic modification is performed for 30 min at an enzymatic temperature of 55°C. The enzyme is inactivated in a 90°C water bath for 30 seconds, and freeze-drying is performed in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0121] (2) Coconut oil is melted in an oven at 60°C, and then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of monodiglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% at a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture is subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture is poured into an ice cream freezing and whipping machine, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0122] Comparative Example 6

[0123] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 30 KV / cm, and the pulse time was 100 μs;

[0124] Then, 0.5% of the complex protease (the mass ratio of papain, alkaline protease, neutral protease, and pepsin was 45:20:20:20) was mixed with the protein, and enzymatic modification was performed for 30 min at 55°C. The enzyme was inactivated in a 90°C water bath for 30 seconds, and freeze-drying was performed in a system at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0125] (2) The coconut oil was melted in an oven at 60°C, and then mixed with the modified soybean protein isolate 4%, coconut oil 12%, mono- and di-glyceride 0.15%, diacetyl tartaric acid ester of mono- and di-glyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% at a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping device, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0126] Comparative Example 7

[0127] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 30 KV / cm, and the pulse time was 5000 μs;

[0128] Then, 0.5% of the complex protease (the mass ratio of papain, alkaline protease, neutral protease, and pepsin was 45:20:20:20) was mixed with the protein, and enzymatic modification was performed for 30 min at 55°C. The enzyme was inactivated in a 90°C water bath for 30 seconds, and freeze-drying was performed in a system at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0129] (2) Coconut oil was oven-melted at 60℃, then mixed with modified soybean protein 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of mono-diglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, essence 0.2% at 80℃ with stirring and sterilization for 20 min. The above mixture was subjected to high pressure homogenization at primary pressure 100 bar and secondary pressure 80 bar, then aged at -4℃ for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine for 30 min, then hardened at -18℃ for 24 h to obtain a soybean protein isolate ice cream.

[0130] The results of Example 1 and Comparative Examples 4-5 are shown in Table 4.

[0131] Table 4

[0132]

[0133]

[0134] As can be seen from Table 4, in Example 1, the overrun of the ice cream was 85.67 and the melt rate was 52.52% under the combined action of pulsed electric field and complex enzyme. In Comparative Example 4 and Comparative Example 6, the soybean protein isolate was modified under too low field strength and too low pulse time, and the overruns were low because the pulsed electric field energy was low and the modification was insufficient. In Comparative Example 5 and Comparative Example 7, the field strength and pulse time of the pulsed electric field were too high, and the pulsed electric field energy was also high, resulting in over-modification of the soybean protein isolate and severe damage to the structure, which could not maintain the interfacial strength, and thus the melt rate was poor.

[0135] Example 11

[0136] The complex protease contains papain, alkaline protease, neutral protease, and pepsin in a mass ratio of 50:20:20:20. The other steps are as in Example 1.

[0137] Example 12

[0138] The complex protease contains papain, alkaline protease, neutral protease, and pepsin in a mass ratio of 40:20:20:20. The other steps are as in Example 1.

[0139] Example 13

[0140] The complex protease contains papain, alkaline protease, neutral protease, and pepsin in a mass ratio of 10:20:20:20. The other steps are as in Example 1.

[0141] Example 14

[0142] The complex protease contains papain, alkaline protease, neutral protease, and pepsin in a mass ratio of 60:20:20:20. The other steps are as in Example 1.

[0143] The results of the determination of Examples 1 and 11-14 are shown in Table 5

[0144] Table 5

[0145]

[0146]

[0147] As can be seen from Table 5, in Example 1, when the ratio of papain, alkaline protease, neutral protease, and pepsin is 45:20:20:20, the expansion rate and the melting rate are 85.67% and 52.52%, respectively. When the ratio of papain, alkaline protease, neutral protease, and pepsin is 50:20:20:20 and 40:20:20:20, the expansion rate and the melting rate change little. When the ratio of papain, alkaline protease, neutral protease, and pepsin is 10:20:20:20, the expansion rate is low, and when the ratio is 60:20:20:20, the melting rate is large.

[0148] Example 15

[0149] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 30 KV / cm, and the pulse time was 1600 μs;

[0150] Then, 0.5% of the complex protease (papain, alkaline protease, neutral protease, and pepsin in a mass ratio of 45:20:20:20) by mass was mixed, and enzymatic modification was performed for 30 min at an enzymatic temperature of 55°C. The enzyme was inactivated in a 90°C water bath for 30 s, and freeze-drying was performed in a system at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0151] (2) Coconut oil was melted in an oven at 60°C, then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of mono-diglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, flavor 0.2% at a ratio, heated at 80°C, stirred and sterilized for 20 min. The above mixture was subjected to high pressure homogenization at a first pressure of 100 bar and a second pressure of 80 bar, then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine for 30 min, then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0152] Example 16

[0153] (1) The soybean protein isolate solution was modified in a PEF device (pulse extraction instrument) for 15 min, with a PEF field strength of 30 KV / cm and a pulse time of 1600 μs;

[0154] Then mixed with 0.5% of protease (mass ratio of papain, alkaline protease, neutral protease, pepsin 45:20:20:20) by mass, and enzymatically modified for 30 min at a temperature of 50°C. The enzyme was inactivated by heating in a 90°C water bath for 30 seconds, and freeze-dried in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0155] (2) Coconut oil was melted in an oven at 60°C, then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of mono-diglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, flavor 0.2% at a ratio, heated at 80°C, stirred and sterilized for 20 min. The above mixture was subjected to high pressure homogenization at a first pressure of 100 bar and a second pressure of 80 bar, then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine for 30 min, then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0156] Example 17

[0157] (1) The soybean protein isolate solution was modified in a PEF device (pulse extraction instrument) for 15 min, with a PEF field strength of 30 KV / cm and a pulse time of 1600 μs;

[0158] Subsequently mixed with 0.5% of the protease by weight of the protein, and then enzymatically modified for 30 min at 60°C. The enzyme was inactivated in a 90°C water bath for 30 seconds, and freeze-dried in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0159] (2) Coconut oil was melted in an oven at 60°C, and then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglycerides of fatty acids 0.15%, diacetyl tartaric acid esters of mono-diglycerides 0.07%, sucrose esters 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% at a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0160] Example 18

[0161] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, with a PEF field strength of 30 KV / cm and a pulse time of 1600 μs;

[0162] Subsequently mixed with 0.5% of the protease by weight of the protein, and then enzymatically modified for 30 min at 60°C. The enzyme was inactivated in a 90°C water bath for 30 seconds, and freeze-dried in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0163] (2) Coconut oil was melted in an oven at 60°C, and then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglycerides of fatty acids 0.15%, diacetyl tartaric acid esters of mono-diglycerides 0.07%, sucrose esters 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% at a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0164] Example 19

[0165] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 30 KV / cm, and the pulse time was 1600 μs;

[0166] Then, 0.5% of the complex protease (the mass ratio of papain, alkaline protease, neutral protease, and pepsin was 45:20:20:20) was mixed with the protein mass, and enzymatic modification was performed for 30 min at 80°C. The enzyme was inactivated by heating in a 90°C water bath for 30 seconds, and freeze-drying was performed in a system at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0167] (2) The coconut oil was melted in an oven at 60°C, and then mixed with the modified soybean protein isolate 4%, coconut oil 12%, mono- and di-glycerides 0.15%, diacetyl tartaric acid esters of mono- and di-glycerides 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% at a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream material liquid. The plant-based ice cream material liquid was poured into an ice cream freezing and whipping device, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0168] The determination results of Examples 15-19 are shown in Table 6.

[0169] Table 6

[0170]

[0171] As can be seen from Table 6, in the process of adding a large amount of plant protein in the modification of soybean protein isolate into ice cream, when only the enzymatic temperature is changed, in the further preferred range of 50°C to 60°C, the melting rate and the overrun of the ice cream are little affected, when the enzymatic temperature is lower than the further preferred 30°C, the enzymatic temperature is not reached, the enzymatic is not complete, and the overrun is greatly reduced, and when the enzymatic temperature is higher than the further preferred 80°C, the complex protease is inactivated at high temperature, and the overrun is also greatly reduced.

[0172] Example 20

[0173] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 30 KV / cm, and the pulse time was 1400 μs;

[0174] Subsequently, 0.5% of the complex protease (papain, alkaline protease, neutral protease, pepsin, mass ratio 45:20:20:20) was mixed with the protein mass, and enzymatic modification was performed for 30 min at 55°C. The enzyme was inactivated in a 90°C water bath for 30 seconds, and freeze-drying was performed in a system at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0175] (2) Coconut oil was melted in an oven at 60°C, and then modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of monodiglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% were mixed. The mixture was heated to 80°C, stirred, and sterilized for 20 min. The mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping device, and whipped for 30 min. The ice cream was hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0176] Example 21

[0177] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, and the PEF field strength was 30 KV / cm and the pulse time was 1400 μs.

[0178] Subsequently, 0.5% of the complex protease (papain, alkaline protease, neutral protease, pepsin, mass ratio 45:20:20:20) was mixed with the protein mass, and enzymatic modification was performed for 25 min at 55°C. The enzyme was inactivated in a 90°C water bath for 30 seconds, and freeze-drying was performed in a system at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0179] (2) Coconut oil was melted in an oven at 60°C, and then modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of monodiglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% were mixed. The mixture was heated to 80°C, stirred, and sterilized for 20 min. The mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping device, and whipped for 30 min. The ice cream was hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0180] Example 22

[0181] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 30 KV / cm, and the pulse time was 1400 μs;

[0182] Then mixed with 0.5% of the protease (the mass ratio of papain, alkaline protease, neutral protease, and pepsin was 45:20:20:20) by mass of the protein, and enzymatic modification was performed for 35 min at 55°C. The enzyme was inactivated in a 90°C water bath for 30 seconds, and freeze-drying was performed in a system at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0183] (2) The coconut oil was melted in an oven at 60°C, and then mixed with the modified soybean protein isolate 4%, coconut oil 12%, mono- and di-glycerides of fatty acids 0.15%, diacetyl tartaric acid esters of mono- and di-glycerides 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% in a ratio, heated and stirred at 80°C, and sterilized for 20 min. The above mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping device, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0184] Example 23

[0185] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 30 KV / cm, and the pulse time was 1400 μs;

[0186] Then mixed with 0.5% of the protease (the mass ratio of papain, alkaline protease, neutral protease, and pepsin was 45:20:20:20) by mass of the protein, and enzymatic modification was performed for 15 min at 55°C. The enzyme was inactivated in a 90°C water bath for 30 seconds, and freeze-drying was performed in a system at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0187] (2) Coconut oil was oven-melted at 60°C, then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of monodiglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, flavor 0.2% at a ratio, heated at 80°C, stirred and sterilized for 20 min. The above mixture was subjected to high pressure homogenization at a first pressure of 100 bar and a second pressure of 80 bar, then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine for 30 min, then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0188] Example 24

[0189] (1) The soybean protein isolate solution was modified in a PEF device (pulse extraction instrument) for 15 min, with a PEF field strength of 30 KV / cm and a pulse time of 1400 μs;

[0190] Then mixed with 0.5% of protease (mass ratio of papain, alkaline protease, neutral protease, pepsin 45:20:20:20) by mass, and enzymatically modified for 55 min at a temperature of 55°C. The enzyme was inactivated by heating in a 90°C water bath for 30 seconds, and freeze-dried in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0191] (2) Coconut oil was oven-melted at 60°C, then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of monodiglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, flavor 0.2% at a ratio, heated at 80°C, stirred and sterilized for 20 min. The above mixture was subjected to high pressure homogenization at a first pressure of 100 bar and a second pressure of 80 bar, then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine for 30 min, then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0192] The determination results of Examples 20-24 are shown in Table 7.

[0193] Table 7

[0194]

[0195] As can be seen from Table 7, in the process of modifying soybean protein isolate into high- added plant protein in ice cream, when only the enzyme hydrolysis time is changed, the melting rate and overrun of the ice cream are little affected in the further preferred range of 25-35℃, while in the enzyme hydrolysis time protection range of the present application, the enzyme hydrolysis is not complete when the temperature is lower than the further preferred 15℃, the overrun is greatly reduced, and the enzyme hydrolysis is excessive when the temperature is higher than the further preferred 55℃, leading to a significant increase in the melting rate.

[0196] Comparative Example 8

[0197] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 30 KV / cm, and the pulse time was 1400 μs;

[0198] Then, 0.5% of the complex protease (the mass ratio of papain, alkaline protease, neutral protease, and pepsin was 45:20:20:20) was mixed with the protein, and the enzyme hydrolysis modification was performed for 30 min at 90℃. The enzyme was inactivated in a 90℃ water bath for 30 seconds, and freeze-drying was performed in a system with a temperature of -40 to -10℃ and a vacuum degree of 13 to 40 Pa.

[0199] (2) The coconut oil was melted in an oven at 60℃, and then mixed with the modified soybean protein isolate at a ratio of 4%, coconut oil 12%, mono- and di-glycerides 0.15%, diacetyl tartaric acid esters of mono- and di-glycerides 0.07%, sucrose esters 0.18%, sucrose 8%, glucose syrup 4%, fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2%, heated and stirred at 80℃, and sterilized for 20 min. The above mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4℃ for 12 h to obtain a plant-based ice cream material. The plant-based ice cream material was poured into an ice cream freezing and whipping device, and whipped for 30 min, and then hardened at -18℃ for 24 h to obtain a soybean protein isolate ice cream.

[0200] Comparative Example 9

[0201] (1) The soybean protein isolate solution was placed in a PEF device (pulse extraction instrument) for modification for 15 min, the PEF field strength was 30 KV / cm, and the pulse time was 1400 μs;

[0202] Then, 0.5% of the complex protease (the mass ratio of papain, alkaline protease, neutral protease, and pepsin was 45:20:20:20) was mixed with the protein, and the enzyme hydrolysis modification was performed for 30 min at 90℃. The enzyme was inactivated in a 90℃ water bath for 30 seconds, and freeze-drying was performed in a system with a temperature of -40 to -10℃ and a vacuum degree of 13 to 40 Pa.

[0203] (2) Coconut oil was oven melted at 60°C, then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of mono-diglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, flavor 0.2% at 80°C, stirred and sterilized for 20 min. The above mixture was subjected to high pressure homogenization at primary pressure 100 bar and secondary pressure 80 bar, then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine for 30 min, then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0204] Comparative Example 10

[0205] (1) The soybean protein isolate solution was modified in a PEF device (pulse extraction instrument) for 55 min, with a PEF field strength of 30 KV / cm and a pulse time of 1400 μs;

[0206] Then mixed with 0.5% of the compound protease (mass ratio of papain, alkaline protease, neutral protease, pepsin 45:20:20:20) by weight, and subjected to enzymatic modification for 5 min at a temperature of 55°C. The enzyme was inactivated by water bath at 90°C for 30 seconds, and freeze-drying was performed in a system with a vacuum degree of 13-40 Pa at -40 to -10°C.

[0207] (2) Coconut oil was oven melted at 60°C, then mixed with modified soybean protein isolate 4%, coconut oil 12%, mono-diglyceride 0.15%, diacetyl tartaric acid ester of mono-diglyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, flavor 0.2% at 80°C, stirred and sterilized for 20 min. The above mixture was subjected to high pressure homogenization at primary pressure 100 bar and secondary pressure 80 bar, then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine for 30 min, then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0208] Comparative Example 11

[0209] (1) The soybean protein isolate solution was modified in a PEF device (pulse extraction instrument) for 15 min, with a PEF field strength of 30 KV / cm and a pulse time of 1400 μs;

[0210] Subsequently, 0.5% of the protein was mixed with a compound protease (papain, alkaline protease, neutral protease, and pepsin in a mass ratio of 45:20:20:20), and enzymatic modification was performed for 80 min at 55°C. The enzyme was inactivated by heating in a water bath at 90°C for 30 seconds, and freeze-drying was performed at -40 to -10°C and a vacuum degree of 13 to 40 Pa.

[0211] (2) Coconut oil was melted in an oven at 60°C, and then mixed with modified soybean protein 4%, coconut oil 12%, mono- and di-glyceride 0.15%, diacetyl tartaric acid ester of mono- and di-glyceride 0.07%, sucrose ester 0.18%, sucrose 8%, glucose syrup 4%, high fructose syrup 2%, xanthan gum 0.5%, carrageenan 0.1%, carboxymethyl cellulose 0.1%, and essence 0.2% at a ratio of 80°C, heated, stirred, and sterilized for 20 min. The mixture was subjected to high-pressure homogenization at a primary pressure of 100 bar and a secondary pressure of 80 bar, and then aged at -4°C for 12 h to obtain a plant-based ice cream mixture. The plant-based ice cream mixture was poured into an ice cream freezing and whipping machine, and whipped for 30 min, and then hardened at -18°C for 24 h to obtain a soybean protein isolate ice cream.

[0212] The results of Examples 20 and Comparative Examples 8 to 11 are shown in Table 8.

[0213] Table 8

[0214]

[0215]

[0216] As can be seen from Table 8, in Example 20, the expansion rate of the ice cream was 84.99% and the melting rate was 51.07% when the pulse electric field and the compound enzyme enzymolysis were combined. In Comparative Example 8 and Comparative Example 9, the soybean protein isolate was modified at too high a temperature and too low a temperature, respectively, and the expansion rates were low because the enzyme was inactivated at too high a temperature and the enzyme activity was too low at too low a temperature, so that the enzymolysis reaction could not occur. In Comparative Example 10, the enzymolysis time was too short, the enzymolysis was not complete, and the expansion rate was low. In Comparative Example 11, the enzymolysis time was too long, and the melting rate was greatly increased due to excessive enzymolysis.

[0217] From Tables 1, 2, 5, 6 and 7, it can be seen that in the process of modifying SPI into plant protein for high addition in ice cream by combining pulsed electric field and complex enzyme hydrolysis, there are further preferred ranges of the field strength and pulse time of pulsed electric field, the proportion of papain in complex protease and the hydrolysis temperature and time of complex protease. When the field strength or pulse time of pulsed electric field is within the protection range of the present patent but exceeds the further preferred range, the protein structure is greatly damaged, resulting in that part of the protein cannot be modified into plant protein suitable for addition in ice cream, and thus the melting rate of ice cream is poor. When the field strength or pulse time of pulsed electric field is within the protection range of the present patent but is lower than the further preferred range, the generated capacity is weak, and the protein cannot be sufficiently modified, thus the overrun rate is poor. When the proportion of papain in complex protease exceeds the preferred range, the protein is excessively hydrolyzed, resulting in poor overrun rate of ice cream. When the proportion of papain in complex protease is lower than the preferred range, the protein is not sufficiently hydrolyzed, and thus the properties of ice cream are not sufficiently improved. When the hydrolysis temperature is within the protection range of the present patent but is lower than the further preferred range, the enzyme activity of complex protease is reduced, resulting in insufficient protein hydrolysis. Meanwhile, when the hydrolysis temperature is within the protection range of the present patent but exceeds the further preferred range, part of the complex protease is inactivated at high temperature, resulting in less improvement in the properties of ice cream. When the hydrolysis time is within the protection range of the present patent but exceeds the further preferred range, the hydrolysis is excessive, and the protein structure cannot maintain the stability of interfacial film, resulting in increased melting rate of ice cream. When the hydrolysis time is within the protection range of the present patent but is lower than the further preferred range, the hydrolysis is insufficient, the modification degree is reduced, and the properties of ice cream are less improved.

[0218] Compared with dairy ice cream, plant ice cream has less heat content, is suitable for consumers with lactose intolerance, and meets the needs of people for nutrition and health. Soy protein is a plant protein with rich resources and excellent quality, has good nutritional value and functional properties, and has a protein content of about 40%, an essential amino acid composition close to that of animal protein, a digestion rate close to or exceeding that of animal protein, and a quality significantly better than that of other plant proteins. However, the functional properties of soy protein such as solubility, hydration, emulsification, foaming, gelation and aggregation are still quite different from those of milk protein. In application in an ice cream system, there are defects such as too large viscosity and hardness, low overrun rate, and presence of beany odor. Therefore, there is an urgent need in the art for a method for modifying soy protein and applying it in an ice cream system.

[0219] The application first proposes to use the pulse electric field and the combined enzyme hydrolysis to modify the soybean protein isolate into a modified protein which can completely replace the milk protein in ice cream, avoiding the defects of the traditional method and overcoming the limitations of single field; the pulse electric field has an influence on the insoluble protein structure in the soybean protein isolate, modifying it into soluble protein, and changing the structure of the protein so that the subunit is dissociated, and then the combined enzyme hydrolysis has an influence on the protein function and structural properties, reducing the molecular weight of the protein and improving the physical and chemical properties of the protein, so as to improve its addition in ice cream.

[0220] Outside the field strength and pulse time protection range of the pulse electric field in the application, too high field strength and pulse time will cause the structure of the soybean protein isolate to be excessively damaged, so that the protein is excessively denatured, and too low field strength and pulse time will cause the modification degree of the soybean protein isolate to be small, thereby reducing the subsequent modification degree and the properties of the addition in ice cream; outside the enzyme hydrolysis temperature and enzyme hydrolysis time protection range of the application, too high enzyme hydrolysis temperature and enzyme hydrolysis time will cause excessive enzyme hydrolysis, the molecular weight of the protein is too small, and the interface film strength cannot be maintained, so that the stability of the ice cream is reduced and the melting rate is improved. Too low enzyme hydrolysis temperature and enzyme hydrolysis time will cause insufficient enzyme hydrolysis, the molecular weight of the protein is still large, the interface film strength is too large, a sufficient fat network strength cannot be formed, and the overrun of the ice cream is low.

[0221] It should be noted that the above examples are only used to illustrate the technical solutions of the application and not to limit it, although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the application, and they should be covered in the scope of the application.

Claims

1. A method for modifying soy protein isolate, characterized in that: include, Soy protein isolate was mixed with water and stirred at 600 rpm for 2 to 4 hours at 20 to 25°C. The mixture was then allowed to stand at 4°C for 12 hours to obtain a soy protein isolate solution. This solution was then treated with a pulsed electric field, wherein the field strength of the pulsed electric field ranged from 10 to 50 kV / cm and the pulse duration ranged from 200 to 4000 μs. It is then mixed with a complex protease for enzymatic hydrolysis. The mass ratio of papain, alkaline protease, neutral protease and pepsin in the complex protease is (20-60):(20-30):(20-30):(20-30). The amount of complex protease added ranges from 0.1% to 0.9% of the protein weight. The enzymatic hydrolysis temperature ranges from 30 to 80°C. The enzymatic hydrolysis time is 10 to 60 minutes. The modified liquid was collected, the enzyme was inactivated, freeze-dried, and milled to obtain modified soy protein isolate powder.

2. The modification method as described in claim 1, characterized in that: The field strength of the pulsed electric field ranges from 25 to 35 kV / cm, and the pulse duration is from 1000 to 2000 μs.

3. The modification method as described in claim 1 or 2, characterized in that: The pulsed electric field processing time is 10 to 15 minutes.

4. The modification method as described in claim 1, characterized in that: The mass ratio of papain, alkaline protease, neutral protease, and pepsin in the complex protease is (40-50):(20-30):(20-30):(20-30); the amount of complex enzyme added ranges from 0.4% to 0.6% of the protein weight; the enzymatic hydrolysis temperature ranges from 50 to 60°C; and the enzymatic hydrolysis time is 25 to 35 minutes.

5. The modification method as described in claim 1, characterized in that: The inactivating enzyme was prepared by water bath at 90°C for 30 seconds; freeze-drying conditions: -40 to -10°C, vacuum degree 13 to 40 Pa.

6. Modified soy protein isolate prepared by any one of the modification methods described in claims 1 to 5.

7. The use of the modified soy protein isolate according to claim 6 in the preparation of ice cream.

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