CN115517341A

CN115517341A - Method for preparing bean protein product

Info

Publication number: CN115517341A
Application number: CN202211211099.0A
Authority: CN
Inventors: 唐璐; 尹秀莹; 王雪; 孙挺; 石红丽; 陆思宇; 解庆刚; 蒋士龙; 张永久
Original assignee: Heilongjiang Feihe Dairy Co Ltd
Current assignee: Heilongjiang Beiwei 477 Green Organic Food Co ltd; Heilongjiang North Latitude 47 Plant Protein Co ltd; Heilongjiang Feihe Dairy Co Ltd
Priority date: 2022-09-30
Filing date: 2022-09-30
Publication date: 2022-12-27

Abstract

The present invention relates to a method for preparing a pulse protein product, which comprises: a step of softening a bean material, which comprises a step of heat-treating the bean material at 60 ℃ or higher; freezing the heat-treated bean material to below-16 deg.c for over 20 hr; a thawing step, wherein the frozen bean raw material is thawed; a mechanical crushing step of mechanically crushing the thawed bean material in the presence of water to obtain a water-containing mixed system; and a separation step, namely preheating the aqueous mixed system and then carrying out centrifugal separation to obtain a high-fat component and a low-fat protein component; also included are soy milk products, preferably soy milk beverages, obtained by the method of making.

Description

Method for preparing bean protein product

Technical Field

The invention belongs to the field of food processing, relates to a preparation method of a bean protein product, and particularly relates to a method for separating oil from the bean product to obtain a low-oil protein product. More particularly, it relates to a method for preparing low-fat soybean milk.

Background

In recent years, plant milk is prosperous worldwide, and various beverages such as grains, beans and nuts are developed, so that the plant milk is a good substitute for people who are lactose intolerant, and the plant milk hardly has intestinal reaction when being drunk. Among them, soybean milk products prepared based on various kinds of bean materials, particularly soybean milk products, are increasingly popular and accepted because they contain abundant vitamin E, calcium, iron, and a large amount of proteins, various amino acids, etc. In addition, the soymilk also contains ingredients similar to estrogen, which is helpful for regulating endocrine and relieving premenstrual syndrome; it can also be used for preventing osteoporosis, climacteric syndrome, breast cancer and cardiovascular diseases.

The common soymilk obtained from soybean raw materials is milky-white to faint yellow milky liquid product with good extraction property after grinding soybeans, fully utilizes plant protein resources, improves the protein potency and the biological value, has fragrant and mellow mouthfeel, is smooth but not greasy, and is a healthy and nutritional drink. The soybean protein in such soymilk is a high-quality vegetable protein, and can provide 9 kinds of amino acids which cannot be synthesized by the human body and must be absorbed from the diet. The soybean protein can also improve the burning rate of fat, promote the excretion of excessive cholesterol, keep the cholesterol content in blood at a low level, thereby softening blood vessels, stabilizing blood pressure and preventing obesity.

At present, plant milk and the like are basically produced in the process of grinding, extracting and deslagging to obtain corresponding extracting solutions, such as common soymilk, common walnut milk and the like, and the proportion of fat and protein of the plant milk and the like is related to the original content of the raw materials. When raw materials with high oil content are used, the oil content of the product is also high, but when the protein of the product is increased, the oil content of the product can cause the product to be too greasy, so that the vegetable milk on the market is often a low-protein product. In addition, it is known that the current oil-and-fat separation techniques mainly include a squeezing method, a leaching method, and an aqueous enzymatic method.

However, the conventional method for obtaining the plant milk is not suitable for beverage processing, wherein the heat is high during squeezing to remove oil, the flavor and stability of a finished product are affected, the raw materials after squeezing are easy to oxidize, and when multiple raw materials are mixed for use, the raw materials need to be squeezed respectively, so that the process is complicated. The defatted material obtained by the leaching method is not suitable for making beverage. Although the aqueous enzymatic method can simultaneously obtain grease and protein, the operation condition is mild, and an organic solvent is not used, the protein in the clear liquid is hydrolyzed into peptide fragments, the bitter taste is strong, the protein is not suitable to be used as a beverage base material, all degreasing processes are accompanied with the denaturation of the protein, and the denaturation mode and degree of the protein can influence the flavor of the clear liquid.

Cited document 1 discloses a fat-reducing soybean protein material and a soybean emulsion composition, and a method for producing the same. Adopting fat-containing soybean with NSI in the range of 20-77, adding water to form suspension, and then carrying out solid-liquid separation. Soy milk is produced using the USS process (ultra soy separation) and is isolated similarly to the isolation of raw milk.

Citation 2 discloses a method for preparing natural plant cream, animal and plant cream, and defatted plant protein powder, which comprises the steps of cooking oil-containing plants with hot water or hot steam, carrying out hot grinding, adding an emulsifier and phosphate, and separating by a disk centrifuge.

In the cited document 3, it is proposed that the soybean oil body concentrate is separated from the raw soybean milk by adjusting the acid, and the soybean oil body concentrate is very similar to cream in appearance due to the high oil content, and can be used as a novel plant source cream product; the low-fat soybean protein liquid obtained synchronously has fresh flavor and taste, and can be processed into a novel low-fat vegetable protein beverage.

Although attempts have been made above to produce protein products based on plant materials such as beans, the current processes and processing effects are still insufficient.

Cited documents:

cited document 1: CN102917603B

Cited document 2: CN103651942A

Cited document 3: separation research of soybean oil enrichment based on acid adjustment, juqiaoling and the like, chinese oil and fat 2019,44 (12): 81-85

Disclosure of Invention

Problems to be solved by the invention

As mentioned above, since the protein products based on legume raw materials are rich in nutrients, various attempts have been made in the industry to isolate and reduce the fat content thereof, but it has been found in long-term practice that the usual means based on phase separation, although avoiding the use of organic solvents, are greatly limited in the conditions of isolation, for example:

in the method of producing a fat-reduced soybean protein material disclosed in reference 1, fat-containing soybeans having an NSI in the range of 20 to 77 are used, and water is added to the fat-containing soybeans to separate the solids from the liquid, but a low-protein denatured soybean material having an NSI of 90 or more is generally used in accordance with the requirement of stability of the beverage. Meanwhile, the process is to convert protein into insoluble components for fat removal, and the recovered insoluble components need to be further homogenized and then subjected to solid-liquid separation to remove dietary fibers, so that the soybean emulsified composition can be obtained. Therefore, the raw material selection is limited, and the whole process flow is complex.

The method disclosed in citation 2 is to use the oil crop seeds to remove the shells and peel, then to cook, then to finely grind to 2-5 μm, to add the emulsifier and to grind at 35-50 ℃ to obtain the natural plant cream and the defatted plant protein milk. The food additive is additionally added in the processing process, and the expectation of the current market on the product cleaning label cannot be met. And practice of the invention proves that when the soybean is used as a single raw material, the process cannot achieve the required grinding particle size and the final product fat separation.

In addition, although there are reports of using centrifugation to assist oil-fat separation, the oil-phase particle size distribution in a water-oil-protein system with a complex composition is not ideal, and it is often difficult to obtain ideal processing efficiency by centrifugation, for example, in cited document 1, centrifugation still requires separation in a multi-layer system; alternatively, in some of the attempted centrifugal separation means, it is still necessary to adjust the acidity of the raw material using chemicals to improve the centrifugal treatment efficiency.

Based on the development of the prior art, the invention provides a method for preparing a bean protein product, which can effectively separate grease without adding (chemical) additives, and the bean product obtained by the method has good stability and flavor and is suitable for beverage production, and the obtained high-fat component can also retain good flavor, so that the bean protein product can be suitable for processing various high-fat-demand foods without reprocessing.

Means for solving the problems

After long-term research, the inventor finds that the technical problems can be solved through implementation of the following technical scheme:

[1] the invention provides a method for preparing a bean protein product, wherein the method comprises the following steps:

a step of softening the bean material, which comprises a step of heat-treating the bean material at 60 ℃ or higher;

freezing the heat-treated bean material to below-16 deg.c for over 20 hr;

a step of thawing, in which the frozen bean raw material is thawed;

a mechanical crushing step of mechanically crushing the thawed bean material in the presence of water to obtain a water-containing mixed system; and

and a separation step, namely preheating the water-containing mixed system and then carrying out centrifugal separation to obtain a high-fat component and a low-fat protein component, wherein the content of fat in the low-fat protein component is less than 25% of the protein content.

[2] The method according to [1], wherein the step of softening the legume raw material comprises:

adding water to the bean raw material, so that the mass of the bean raw material after water adding is 2-2.5 times of that of the bean raw material before water adding; and

a heat treatment step, namely heating the bean raw material after being added with water to 80-95 ℃.

[3] The method according to [2], wherein the heat treatment is performed in the presence of water, and the time of the heat treatment is 30min or less.

[4] The method according to any one of [1] to [3], wherein the bean material is selected from one or more of soybeans, black beans, green beans and cyperus esculentus, and optionally one or more of broad beans, red beans, cowpeas, peas, kidney beans, sword beans, lentils, kidney beans and pigeon peas can be added.

[5] The method according to any one of [1] to [4], wherein the freezing step further comprises a step of peeling the beans.

[6] The method according to any one of [1] to [5], wherein in the freezing step, the freezing temperature is-40 ℃ or more, and the freezing time is 24 to 36 hours; in the thawing step, the highest thawing temperature is below 30 ℃.

[7] The method according to any one of [1] to [6], wherein the mechanical crushing step comprises mixing the thawed bean material with water at a ratio of 1: (1.5 to 8); and the water-containing mixed system is the water-containing mixed system after the solid substances are removed.

[8] The method according to any one of [1] to [7], wherein the temperature of the preheating in the step of separating is 45 to 90 ℃, or the centrifugal separation in the step of separating is performed by a disk centrifuge.

[9] The method according to any one of [1] to [8], wherein the oil content of the low-oil protein component is 15 to 25% of the protein content, and the degreasing rate of the low-oil protein component is 50% or more.

[10] The present invention also provides a soybean milk product obtained by the production method according to any one of [1] to [9].

ADVANTAGEOUS EFFECTS OF INVENTION

Through the implementation of the technical scheme, the invention can obtain the following technical effects:

1) Compared with the prior art, the preparation method of the invention does not add any additive, and meets the expectations of the consumers in the food field and the product cleaning label;

2) The preparation method provided by the invention does not need to recover the soybean milk from the precipitate, has simple process operation, obvious centrifugal separation effect and high production efficiency, is suitable for large-scale industrial production, and provides reference for relevant product production practices in the field;

3) The preparation method provided by the invention can produce low-fat soymilk and high-fat soymilk simultaneously, and the two soymilk have high stability and are suitable for further processing of foods such as beverages and the like;

4) The low-fat soymilk prepared by the preparation method provided by the invention has good degreasing effect (more than 50 percent), low fat content and better flavor.

Drawings

FIG. 1: flow chart of preparation method of the invention

Detailed Description

The following describes embodiments of the present invention, but the present invention is not limited to these embodiments. The present invention is not limited to the configurations described below, and various modifications are possible within the scope of the claims, and embodiments and examples obtained by appropriately combining the technical means disclosed in the respective embodiments and examples are also included in the technical scope of the present invention.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Also, unless otherwise indicated, the following terms follow the following definitions:

in the present specification, the numerical range represented by "numerical value a to numerical value B" means a range including the end points of numerical values a and B.

In the present invention, the terms "about" or "substantially" or "essentially" may mean: a value includes the standard deviation of error for the device or method used to determine the value. The numerical ranges and parameters setting forth the invention are approximate, and the values associated with the embodiments are presented herein as precisely as possible. Any numerical value, however, inherently contains certain standard deviations found in their respective testing measurements or methods. Accordingly, unless expressly stated otherwise, it is understood that all ranges, amounts, values and percentages used herein are by weight modified by the term "about". Herein, "about" generally means that the standard deviation of the actual value from the theoretical model or theoretical data is within 3%, preferably 2%, more preferably 1%.

In the present specification, the term "may" includes both the case where a certain process is performed and the case where no process is performed.

In the present description, the terms "milk", "milk" are to be interpreted broadly and may cover both raw milk (i.e. liquid obtained directly from the mammary gland) and standardized milk products (like for example skim milk or whole milk), wherein the concentration of milk fat has been reduced with respect to the original raw milk.

In the present specification, the term "room temperature" or "room temperature" means an indoor temperature of 23 ± 2 ℃.

In this specification, "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

In the present specification, reference to "some particular/preferred embodiments," "other particular/preferred embodiments," "embodiments," and the like, means that a particular element (e.g., feature, structure, property, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments.

The invention provides a method for preparing a protein product based on bean plant raw materials, which can efficiently separate high-fat components and low-fat protein components by processing the bean raw materials through the steps of softening, freezing, unfreezing, mechanical crushing, centrifugal separation and the like without adding any additional additive.

The technical scheme of the invention is obtained based on the following insights:

it has been unexpectedly found that bean materials obtained by softening, particularly by water-heat softening, can be subjected to a subsequent temperature-changing treatment to facilitate subsequent phase separation of components such as fats and proteins in the interior of the bean materials, and although the mechanism thereof is not completely understood, it is presumed that the temperature-changing treatment changes the internal structure of the bean materials due to volume change of water, and that the presence of water during freezing from low temperature to thawing promotes a new distribution state of components such as fats and proteins in the interior of the bean materials, thereby facilitating efficient subsequent separation of fats and proteins by simple crushing (grinding), centrifugation, and the like.

Specifically, the preparation method of the bean protein product comprises the following steps: softening the bean raw material; freezing the heat-treated bean material to below-16 deg.c for over 20 hr; a step of thawing, in which the frozen bean raw material is thawed; a step of mechanically crushing the thawed soybean material in the presence of water to obtain a water-containing mixed system; and a separation step, wherein the water-containing mixed system is heated and then subjected to centrifugal separation to obtain a high-fat component and a low-fat protein component.

In addition, the invention also finds that the oil and fat in the protein are efficiently separated, and the taste of the protein product is also unexpectedly improved.

< legume materials >

In the invention, the plant-derived bean raw material is mainly beans with high fat and protein content, such as one or more of soybeans (soybeans, black beans, green beans or other types of soybeans), cyperus esculentus and the like, and optionally one or more of broad beans, red beans, cowpeas, peas, kidney beans, sword beans, hyacinth beans, kidney beans, pigeon peas and the like can be added.

In some specific embodiments of the present invention, the legume material includes at least soy, preferably the soy is present in an amount of 60 mass% or more, more preferably 80 mass% or more, and even more preferably 90 mass% or more, based on the total weight of the legume material. In other preferred embodiments, the legume material of the present invention is substantially soy material.

There is no limitation in principle on the kind or origin of soybean which can be used in the present invention. May be any kind of soybeans according to the national standard GB1352-2009, and in some preferred embodiments, the soybeans of the present invention may be subjected to an optional soybean roguing step to remove musty beans, damaged grains, wormholes, stone impurities, etc. from the soybeans, resulting in a soybean material suitable for a subsequent processing step.

For any of the species of soybean, there may be enumerated, in general, the following:

soybean (soybean): the seed coat is yellow and light yellow, and the umbilicus is yellow brown, light brown or dark brown, and the seed content is not less than 95%;

green soybean (green bean): the seed coat is green soybean with seed content not less than 95%, and is divided into green tangerine peel kernel soybean and yellow green tangerine peel kernel soybean according to the color of cotyledon;

black soybean (black bean): the seed coat is black soybean with seed grains of not less than 95%. The color of cotyledon is divided into black peel green kernel soybean and black peel yellow kernel soybean;

other soybeans: the seed coat is brown, red soybean with single color or bicolor soybean.

The water content of the above-mentioned legume materials usable in the present invention is not particularly limited in principle, and may be fresh legume materials, dried materials, or a mixture thereof in any ratio.

(step of softening treatment)

In the invention, before the subsequent temperature-changing treatment (freezing-unfreezing), the bean raw materials are softened firstly. The promotion effect of the subsequent temperature-changing treatment on the phase separation can be more shown through the softening treatment, and the softening treatment comprises the step of carrying out heat treatment on the bean raw material at 60 ℃ or more, preferably 70 ℃ or more.

The heat treatment step may be carried out separately (e.g. wet beans), but preferably may be carried out in the presence of water.

In particular, in some exemplary embodiments of the invention, the softening treatment may be performed by means of water-heat.

In some preferred embodiments, the step of softening according to the invention comprises: a step of adding water to the bean material and a step of heat-treating the bean material after water addition.

Step of adding water

According to the invention, through the step of adding water, the bean raw materials can expand in volume after absorbing water, so that on one hand, the internal structure of the bean raw materials can be expanded, and the subsequent separation of grease and protein from the raw materials is facilitated; on the other hand, the softening makes the temperature change more uniform inside the bean material during the subsequent temperature-changing treatment.

The step of adding water is not particularly limited in principle, and in some embodiments of the present invention, the step of adding water may be performed by soaking in water at room temperature or above. An exemplary method includes immersing the bean material in water at a temperature not exceeding 30 ℃, preferably 5 to 25 ℃. The amount of water used for soaking is not particularly limited, and the water may be 2 to 5 times the weight of the bean material. After soaking, the volume of the legume material expands, and, in some preferred embodiments, the legume material after being hydrated is 2 to 2.5 times, preferably 2.2 to 2.4 times, the mass of the legume material before being hydrated. The soaking time is not particularly limited, and the increase in the mass of the bean material after the water addition is satisfactory, but is usually not more than 48 hours.

Step of Heat treatment

In order to achieve a satisfactory softening treatment and improve the subsequent oil-fat separation effect, the softening treatment of the present invention is to heat-treat the water-added bean material after the above-mentioned water-adding step.

Typically, the heat treatment may be carried out directly after the step of adding water, for example, when the bean material has a satisfactory mass increase, the water-bean material mixed system may be directly heated; in other embodiments, the hydrated legume material may be removed (temporarily stored) and placed in additional water, optionally followed by heating, as desired.

The temperature of the heat treatment may be preferably 80 to 95 ℃ and the time of the heat treatment may be 30min or less, and the temperature of the heat treatment may be preferably 85 to 90 ℃ and maintained for 5 to 20min. .

By the above heat treatment, it is considered that there is a significant improvement in the subsequent increase in the total yield of fats and oils and proteins.

(step of peeling)

In the invention, before the subsequent temperature-changing treatment, the step of peeling is carried out from the viewpoint of subsequently improving the grease separation effect of the product.

The specific timing of the peeling step of the bean material is not particularly limited, and for example, in some specific embodiments of the present invention, the bean material may be peeled before the above-mentioned softening step, and typically, the bean material may be dried and then the peel layer may be removed.

The drying method and conditions of the present invention are not particularly limited in principle. The drying method can be natural drying or artificial drying. The natural drying includes sun drying, air drying, etc. Examples of the artificial drying method include hot air drying, contact drying, infrared drying, fluidized bed drying, dielectric drying, and the like. In some preferred embodiments, the drying conditions of the present invention are 55 to 120 ℃ for 5 to 60min; and more preferably, at 80 to 100 ℃ for 10 to 30min.

The dried bean raw material can be applied with pressure in a certain direction, and the bean grains are forced to rotate, so that the action point of force is continuously changed, and the skin and the shell are broken into a plurality of small pieces to be separated from the bean cotyledon; then the soybean grains have a large specific gravity and the skins have a smaller specific gravity after drying by wind separation, and the skins are completely separated from the flowing mixture by air blowing. Preferably, the peeling rate is 80% or more or 90% or more, and more preferably, the peel layer of the bean material is substantially completely removed.

In other embodiments of the invention, the step of peeling may also be performed during or after the step of softening, such as hydrating and heat treating. Typically, the peeling may be performed after the heat treatment. In particular, the mixed system may be mechanically agitated during the heat treatment, and at this time, the skin layer of the bean material may be easily peeled off from the surface of the bean due to the expansion of the bean and the heating effect.

The invention considers that the peeling treatment is beneficial to reducing the viscosity of a mixed system obtained by subsequent mechanical crushing treatment of beans, so that the grease can float upwards more easily, and the effect of grease separation is improved.

(step of temperature changing treatment)

In the present invention, it has been found that improved separation of the final oil and protein is facilitated by subjecting the softened legume material to a temperature swing treatment.

Specifically, the temperature change treatment of the present invention includes a freezing step and a thawing step.

Step of freezing

The freezing step of the invention mainly comprises the step of draining water from the softened soybeans and freezing the soybeans. In this case, the residual moisture on the surface of the bean material may be controlled to be not more than 2% by mass based on the mass of the bean material.

The freezing method and conditions of the present invention are not particularly limited in principle. In some preferred embodiments of the invention, the freezing temperature is from-16 to-40 ℃, the freezing time is not less than 20 hours, such as 24 hours, or from 24 to 36 hours, etc., and the freezing rate can be from 0.1 to 5cm/h, such as from 0.2 to 3cm/h or from 0.3 to 2cm/h, etc.

In other preferred embodiments, the freezing temperature is from-18 ℃ to-25 ℃ and the freezing rate is from 0.1cm/h to 5cm/h, such as from 0.2 cm/h to 3cm/h or from 0.3cm/h to 2cm/h, and the treatment of slow freezing favors the formation of larger ice crystals. In this case, the treatment time for freezing may be suitably extended to 4 days or more, for example, 5 to 8 days.

Through freezing treatment, because the moisture in the bean raw material expands under the freezing condition, the internal structure of the raw material is further changed, and the bean raw material is particularly convenient to separate from subsequent grease and protein.

In addition, the starting point of freezing may be freezing from room temperature.

Step of thawing

The thawing step of the present invention is to thaw the frozen soybeans. The thawing method and conditions of the present invention are not particularly limited in principle. Examples thereof include thawing by immersion in water, thawing by heating, and rapid microwave thawing. In order to ensure sanitation and control of lipoxygenase during thawing, in some preferred embodiments of the invention, thawing conditions may be thawing in water at 4-10 ℃ or thawing by heating to 80-95 ℃.

As for the thawing end point temperature, it is usually desirable that it is not more than 30 ℃ and preferably it may be 15 to 25 ℃ or room temperature.

(step of mechanical crushing)

In the present invention, the thawed soybean material is mechanically crushed to separate oil, protein, other water-soluble components, and the like from components such as fiber.

There is in principle no particular restriction as to the specific method of mechanical disruption. From the viewpoint of convenience of handling, the grinding may be performed in the presence of water.

Grinding is mainly to add water into the unfrozen soybeans to grind so as to obtain a soybean milk system.

The polishing method and conditions of the present invention are not particularly limited in principle. The food industry equipment used may be listed as: disc mills, roller mills, twin-roll mills, rotor mills, planetary ball mills, flake mills, fluid bed jet mills, colloid mills, sand wheel mills, rotor mills, knife mills, cyclone mills, impact mills, hammer mills, cone mills, and the like. In some preferred embodiments of the present invention, the ratio of legume raw material to added water in the grinding step is 1: (1.5-8) and the water temperature is 20-90 ℃; more preferably, the ratio of soybean to water added is 1: (2.5-5) and the water temperature is 80-85 ℃.

After mechanical disruption, an aqueous mixing system can be obtained, which comprises protein components, carbohydrates, fats and oils, etc., usually in the form of an emulsion system containing solids. Preferably, the solid material can be separated and removed by further filtration means.

(step of oil separation)

The step of oil-and-fat separation of the present invention is also referred to as "separation step", that is, by this separation step, oil-and-fat and protein components in the aqueous system obtained in the grinding step are mainly separated. Specifically, the step of fat separation of the present invention mainly includes a step of centrifugal treatment, and it has also been found that the effect of efficiently separating fat can be achieved by controlling the flow rate of the centrifuge (adjusting the flow rate of the centrifuge to 5 to 30% of the rated flow rate of the centrifuge) at the time of centrifugal treatment.

In addition, from the viewpoint of the effect of promoting the separation of oil and fat, it is preferable to subject the aqueous system obtained in the step of mechanical disruption to a preheating treatment before the centrifugal treatment.

Step of preheating

By the step of preheating, it is considered that the phase separation of the protein component and the oil component in the aqueous system can be promoted. With respect to the conditions for the preheating of the present invention, there is in principle no particular limitation. In some particular embodiments of the invention, it may be desirable to preheat the milled aqueous system to a temperature of from 45 to 90 deg.C, preferably from 55 to 75 deg.C.

Step of centrifugation

The invention can separate the grease and protein components in the water-containing system after the preheating treatment more efficiently and conveniently by centrifugal separation treatment.

There is in principle no particular restriction on the apparatus which can be used for the separation according to the invention. Food separation devices that may be enumerated are: centrifugal separators, air separators, cyclone separators, vibratory separators, particle separators, drum separators, disk separators, and the like. In some preferred embodiments of the invention, a disc centrifuge is used.

In some embodiments of the invention, the centrifuge may be operated at 8000 to 12000RPM for centrifugation. Further, the flow rate of the centrifuge is adjusted to 5-30% of the rated flow rate of the centrifuge (especially for a disc centrifuge), so as to avoid that the centrifugal separation load is too large due to too high flow rate and the efficiency of centrifugal treatment is reduced.

And (3) performing centrifugal separation to obtain light-phase liquid and heavy-phase liquid, wherein the light-phase liquid is a high-fat component, and the heavy-phase liquid is a low-fat protein component.

In some specific embodiments, the content of the oil in the high oil component is more than 100% of the protein content, such as 150% to 600%, preferably 170% to 500%, more preferably 200% to 400%; in the low-fat protein component, the content of the fat is less than 25% of the protein content, such as 10-25%, preferably 15-24%, more preferably 15-22%; in addition, the protein component of the low fat may have a defatting ratio of 50% or more, preferably 55% or more, more preferably 60% or more or 65% or more. The lower oil content, higher protein content of the low-oil protein component also unexpectedly results in improved mouthfeel.

Therefore, the present invention can conveniently obtain the above two components in the form of a two-phase liquid in the centrifugal separation process by the aforementioned respective steps of processes, compared to the prior art.

The high fat fraction may be further extracted to obtain vegetable oil, and the low fat fraction may be used for the production of a soybean milk product or the like as described below.

< second aspect >

In a second aspect of the invention, a soy milk product is provided.

The soy milk product of the present invention may optionally contain other ingredients, such as other nutritional supplements, other food supplements or food additives, in addition to being directly prepared by the preparation method of the present invention (low-fat protein fraction). Preferably, the soy milk product of the present invention is a soy milk beverage.

Other ingredients that may be added are not particularly limited and may include one or more of the following components: proteins, essential carbohydrates, dietary fibers, supplemental elements, vitamins, plant or dietary components, and the like.

Wherein the protein is selected from at least one of whey protein powder, soy protein isolate, whole milk powder, whole egg powder, lactoferrin, bovine colostrum, amino acid and protein peptide; the amino acid is at least one selected from L-lysine-L-glutamic acid, L-arginine, L-tryptophan, L-glutamine, taurine, L-valine, L-isoleucine and L-leucine; the protein peptide is selected from one or more of soybean oligopeptide, wheat protein peptide, silkworm pupa protein peptide, marine fish oligopeptide powder, cola peptide, amino peptide and egg albumin peptide.

The carbohydrate includes starch or modified starch. The dietary fiber comprises one or more of inulin, konjac flour, galacto-oligosaccharide, fructo-oligosaccharide, isomalto-oligosaccharide, soybean polysaccharide, cyclodextrin, resistant dextrin and soybean fiber.

The supplementary elements are selected from metal ion salts of organic acids, such as one or more of calcium citrate, calcium lactate, calcium hydrogen phosphate, potassium gluconate, sodium citrate, ferrous gluconate, potassium iodide, zinc gluconate, sodium selenite, copper gluconate, chromium sulfate, manganese gluconate, and magnesium gluconate.

The vitamins are selected from one or more of vitamin A, beta-carotene, vitamin D3, vitamin E, vitamin K1, vitamin B2, vitamin B6, vitamin B12, vitamin C, pantothenic acid, folic acid, nicotinic acid, choline, inositol, and biotin.

The plant or dietary component comprises one or more of potato, vegetable, bacteria and algae, nut and seed, fish and shrimp, livestock meat, and fruit.

Examples

Hereinafter, the present invention will be further specifically described by way of specific examples. The reagents, methods and apparatus employed in the present invention are those conventional in the art, unless otherwise specified.

< materials and apparatus >

In the examples section that follows, the starting materials used are as follows, unless otherwise indicated.

Soybean: (commercially available)

Equipment: commercial soybean dry and wet huller, milk fat separator and freezer

< specific examples >

Example 1

1. Pretreatment of soybeans: soaking cleaned semen glycines in 3 times of 20 deg.C water for 10 hr. Decocting, soaking, and maintaining at 95 deg.C for 10min. Peeling, wherein the peeling rate is 90%;

2. freezing: the freezing speed is 0.1cm/h, the temperature is increased to-18 ℃, and the freezing holding time is 7 days;

3. unfreezing: thawing soybean in water at 4 deg.C;

4. grinding: wet soybean: water =1:3.5, the temperature is 80 ℃;

5. degreasing: regulating the flow rate to 8% of the rated flow rate of a disc centrifuge, preheating the soybean milk to 65 ℃, and separating by the disc centrifuge to obtain light phase liquid and heavy phase liquid, wherein the light phase liquid is a high-fat component, and the heavy phase liquid is low-fat soybean milk.

Example 2

1. Pretreatment of soybeans: drying cleaned semen glycines at 85 deg.C for 20min, cooling, peeling to a peeling rate of 85%, decocting, mixing peeled semen glycines with water, heating to 95 deg.C, and maintaining for 10min;

2. freezing: the freezing speed is 0.5cm/h, the freezing time is 10 days when the temperature is reduced to-18 ℃;

3. unfreezing: thawing soybean in water at 4 deg.C;

4. grinding: wet soybean: water =1:3.5, the temperature is 85 ℃;

5. degreasing: regulating the flow rate to 8% of the rated flow rate of the disc centrifuge, preheating the soybean milk to 65 ℃, and separating by the disc centrifuge to obtain light phase liquid and heavy phase liquid, wherein the light phase liquid is a high-fat component, and the heavy phase liquid is low-fat soybean milk.

Example 3

1. Pretreatment of soybeans: soaking cleaned semen glycines in 3 times of 18 deg.C water for 16 hr, decocting, maintaining at 95 deg.C for 5min, and peeling to obtain 90% peel;

2. freezing: freezing at-18 deg.C at a speed of 0.3cm/h for 4 days;

3. and (3) unfreezing: thawing soybean in water at 4 deg.C;

4. grinding: wet soybean: water =1:3.5, the temperature is 85 ℃;

5. degreasing: regulating the flow rate to 12% of the rated flow rate of the disc centrifuge, preheating the soybean milk to 65 deg.C, and separating with the disc centrifuge to obtain light phase liquid and heavy phase liquid, wherein the light phase liquid is high fat component, and the heavy phase liquid is low fat soybean milk.

Example 4

1. Pretreatment of soybeans: soaking cleaned semen glycines in 3 times of 15 deg.C water for 22 hr, decocting, maintaining at 90 deg.C for 15min, peeling, and peeling at a rate of 95%;

2. freezing: freezing at-18 deg.C at a speed of 0.3cm/h for 14 days

3. Unfreezing: thawing soybean in water at 4 deg.C

4. Grinding: wet soybean: water =1:4.5 at 90 deg.C

5. Degreasing: regulating flow rate to 8% of rated flow rate of disc centrifuge, preheating soybean milk to 70 deg.C, and separating with disc centrifuge to obtain light phase liquid and heavy phase liquid, wherein the light phase liquid is high fat component, and the heavy phase liquid is low fat soybean milk.

Example 5

1. Pretreatment of soybeans: soaking cleaned semen glycines in 3 times of 15 deg.C water for 22 hr, decocting at 85 deg.C for 20min, and peeling to remove 90% of peel;

2. freezing: freezing at-18 deg.C at a speed of 1cm/h for 7 days;

3. unfreezing: thawing soybean in water at 4 deg.C;

4. grinding: wet soybean: water =1:3, the temperature is 80 ℃;

5. degreasing: regulating flow rate to 10% of rated flow rate of disc centrifuge, preheating soybean milk to 70 deg.C, and separating with disc centrifuge to obtain light phase liquid and heavy phase liquid, wherein the light phase liquid is high fat component, and the heavy phase liquid is low fat soybean milk.

Comparative example 1

1. Pretreating semen glycines, soaking cleaned semen glycines in 3 times of 20 deg.C water for 10 hr, decocting, and maintaining at 95 deg.C for 10min;

2. freezing: the freezing speed is 0.1cm/h, the freezing time is 7 days when the temperature is reduced to-18 ℃;

3. and (3) unfreezing: thawing soybean in water of 4 deg.C;

4. grinding: wet soybean: water =1:3.5, the temperature is 80 ℃;

Comparative example 2

1. Pretreatment of soybeans: soaking cleaned soybean in 3 times of 18 deg.C water for 16 hr, without cooking soybean, peeling, and peeling to obtain peel ratio of 90%;

2. freezing: freezing at-18 deg.C at a speed of 0.3cm/h for 4 days;

3. and (3) unfreezing: thawing soybean in water of 4 deg.C;

4. grinding: wet soybean: water =1:3.5, the temperature is 85 ℃;

Comparative example 3

1. Pretreatment of soybeans: soaking cleaned soybean in 3 times of 15 deg.C water for 22 hr, peeling, and peeling to a rate of 95%;

2. freezing: the freezing speed is 0.3cm/h, the temperature is increased to-18 ℃, and the freezing holding time is 14 days;

3. unfreezing: thawing soybean in water at 4 deg.C;

4. boiling the beans: maintaining the thawed soybean at 90 deg.C for 15min;

5. grinding: wet soybean: water =1:4.5, the temperature is 90 ℃;

6. degreasing: regulating the flow rate to 8% of the rated flow rate of a disc centrifuge, preheating the soybean milk to 70 ℃, and separating by the disc centrifuge to obtain light phase liquid and heavy phase liquid, wherein the light phase liquid is a high-fat component, and the heavy phase liquid is low-fat soybean milk.

Comparative example 4

2. grinding: wet soybean: water =1:3, the temperature is 80 ℃;

3. degreasing: regulating flow rate to 10% of rated flow rate of disc centrifuge, preheating soybean milk to 70 deg.C, and separating with disc centrifuge to obtain light phase liquid and heavy phase liquid, wherein the light phase liquid is high fat component, and the heavy phase liquid is low fat soybean milk.

Comparative example 5

1. Pretreatment of soybeans: soaking cleaned semen glycines in 3 times of 15 deg.C water for 22 hr, decocting at 85 deg.C for 20min, and peeling to obtain 90% peel;

2. freezing: the freezing speed is 1cm/h, the temperature is increased to-18 ℃, and the freezing retention time is 7 days;

3. unfreezing: thawing soybean in water of 4 deg.C;

4. grinding: wet soybean: water =1:3, the temperature is 80 ℃;

5. degreasing: regulating flow rate to 80% of rated flow rate of disc centrifuge, preheating soybean milk to 70 deg.C, and separating with disc centrifuge to obtain light phase liquid and heavy phase liquid, wherein the light phase liquid is high fat component, and the heavy phase liquid is low fat soybean milk.

Comparative example 6 (production method of cited document 2)

Softening peeled semen glycines in a steaming and boiling pot with 70 deg.C steam for 30min, adding 8 times of 70 deg.C water, stirring, grinding with colloid mill for 5 times until the particle diameter has no obvious change, and centrifuging at 35 deg.C with disc centrifuge rated flow rate of 80%.

< results and analysis >

The defatted ratio of the soymilk of the above examples and comparative examples was examined and calculated, wherein:

the fat-free ratio =100% [ 1-amount of heavy-phase liquid fat/amount of raw soymilk fat ].

And simultaneously, carrying out sensory evaluation on the obtained low-fat soymilk, wherein the specific scoring standard is as follows: the color is creamy yellow to milky white, the mouthfeel is smooth and fine, the soybean milk has the original characteristic bean fragrance of the soybean milk, and the soybean milk has no green grass flavor and bitter taste, and the score is 5 points at most. The results are shown in table 1:

table 1:

note: comparative example 6 the percentage of fat removed was 0% because the separator disc was clogged and no results were obtained, "-" is given to the fat content of the low-fat component, and 2 is given to the sensory evaluation part because of the sensation of sludge.

From the above results, it can be seen that: compared with example 1, comparative example 1 has high viscosity due to no peeling, so the degreasing ratio is reduced; compared with example 3, comparative example 2 has a heavy beany flavor and a relatively low degree of degreasing of the resulting soy milk product because the cooking step is not performed; compared with the example 4, the comparative example 3 has heavier fishy smell and low degreasing degree because the peeling step is carried out firstly and then the bean is frozen and then the bean is boiled; comparative example 4 has a lower degree of defatting of the resulting soy milk product compared to example 5 because the freezing step was not performed; compared with example 5, comparative example 5 has a lower degree of degreasing of the obtained product due to a larger flow rate into the disc centrifuge at the degreasing step; comparative example 6 the result of the degree of degreasing was not obtained because the separator disc was clogged, and the sensory evaluation score was relatively low.

It should be noted that, although the technical solutions of the present invention are described by specific examples, those skilled in the art can understand that the present invention should not be limited thereto.

While embodiments of the present invention have been described above, the above description is illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or technical improvements to the market, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Industrial applicability

The composition of the present invention can be industrially produced and can be applied to foods, beverages and the like.

Claims

1. A method of preparing a pulse protein product, said method comprising:

a step of softening a bean material, which comprises a step of heat-treating the bean material at 60 ℃ or higher;

freezing the heat-treated bean material to below-16 deg.c for over 20 hr;

a thawing step, wherein the frozen bean raw material is thawed;

2. The method of claim 1, wherein the step of softening the legume material comprises:

3. The method according to claim 2, wherein the heat treatment is performed in the presence of water, and the time of the heat treatment is 30min or less.

4. A method according to any one of claims 1 to 3, wherein the legume material is selected from one or more of soybeans, black beans, green beans, cyperus esculentus, optionally with the addition of one or more of broad beans, red beans, cowpeas, peas, beans, jack beans, lentils, kidney beans, and pigeon peas.

5. The method according to any one of claims 1 to 4, wherein the freezing step is preceded by a step of dehulling the legumes.

6. The method according to any one of claims 1 to 5, wherein the freezing temperature in the freezing step is-40 ℃ or higher, and the freezing time is 24 to 36 hours; in the thawing step, the highest thawing temperature is below 30 ℃.

7. The method according to any one of claims 1 to 6, wherein in the step of mechanical crushing, the thawed legume material is mixed with water and ground at a temperature of 20 to 90 ℃, and the legume material and water are present in a ratio of 1: (1.5 to 8); the water-containing mixed system is a water-containing mixed system after solid substances are removed.

8. The method according to any one of claims 1 to 7, wherein the temperature of the preheating in the step of separating is 45 to 90 ℃, or wherein the centrifugation in the step of separating is performed by a disk centrifuge.

9. The method according to any one of claims 1 to 8, wherein the fat content of the protein fraction of the low fat is 15 to 25% of the protein content, or wherein the fat-free ratio of the protein fraction of the low fat is 50% or more.

10. A soy milk product obtained by the production method according to any one of claims 1 to 9.