CN112535212A - Pretreatment method of catechin raw material and fruit juice milk containing catechin - Google Patents

Abstract

The invention relates to the field of food, in particular to a method for pretreating catechin raw materials and fruit juice milk containing catechin. In particular, the present invention relates to a method for pretreating a catechin raw material, the catechin raw material pretreated by the method, and use thereof for preparing food or medicine. The invention also relates to a food product (e.g. fruit juice milk) comprising the catechin raw material pre-treated by the method or prepared from a composition comprising the catechin raw material pre-treated by the method. The invention also relates to a method for preparing fruit juice milk, which comprises the step of pretreating catechin raw materials by the pretreatment method.

Description

Pretreatment method of catechin raw material and fruit juice milk containing catechin

Technical Field

The present invention relates to the field of food, and more particularly, to a method for pretreating catechin raw materials, juice milk containing catechin, and a method for preparing the juice milk.

Background

Milk (Milk) is one of the oldest natural drinks, known as "white blood". The milk has at least 100 kinds of complex components, and the main components include water, fat, phospholipid, protein, lactose, inorganic salt, etc. The milk contains rich mineral substances such as calcium, phosphorus, iron, zinc, copper, manganese and molybdenum, and most rarely, the milk is the best source of calcium for human bodies, and the proportion of calcium and phosphorus is very proper, so that the milk is beneficial to the absorption of calcium.

The fruit juice milk is a prepared milk product prepared by adding fruit juice or fruit pulp raw materials, sweet substances, stabilizers and the like into milk, and has the characteristics of unique flavor, nutrition, health, fashion and fashion. The fruit juice or fruit pulp raw materials are added into the fruit juice milk product, so that the product contains abundant vitamins and fiber substances, and powerful support is provided for the life activities of a human body. At present, the market has more fruit juice milk, and the fruit juice milk can be sold at normal temperature or at low temperature according to different selling forms, so that the fruit juice milk is popular among consumers.

Catechin compounds are phenolic active substances extracted from natural plants such as tea, have 2-phenylbenzodihydropyran structure, belong to flavanol compounds, and mainly comprise Catechin (Catechin, C), Epicatechin (EC), Epigallocatechin (EGC), Epicatechin gallate (ECG), Epigallocatechin gallate (EGCG), etc. The catechin content in green tea is high. In two clinical experiments carried out by research institutions on the efficacy of high-catechin content in green tea, on the premise of not changing diet and physical activities, after Chinese healthy men and women who are mildly overweight drink the high-catechin content green tea for 90 days, the body weight, the waist circumference and the visceral fat are obviously reduced, which shows that catechin in the green tea may have specific beneficial effects on the distribution of body fat, particularly the distribution of abdominal fat, and has a certain effect on controlling central obesity.

At present, no research exists for adding catechin raw materials into fruit juice milk, mainly because catechin is dark in color, and when the adding amount is high, the overall appearance of the product is easily influenced; meanwhile, catechin has certain bitter taste and has great influence on the integral flavor of the product. In addition, the characteristics of catechin are easily influenced by milk protein, and the stability of catechin is obviously damaged after being directly added into milk and subjected to industrial processing units such as heat treatment and the like.

Disclosure of Invention

The invention provides a method for pretreating catechin raw materials, which can effectively improve the color, taste and stability of catechin-containing food (such as fruit juice milk). The pretreated catechin is added into the fruit juice milk, so that the sensory properties of the product are not influenced, the product has a good weight control effect, and meanwhile, the stability of the product is improved to a certain extent. Thus, the present application provides the following inventions:

in one aspect, the present application provides a method for pretreating a catechin feedstock, comprising the steps of:

step I: providing an ethyl acetate solution of a catechin raw material, and providing a buffer solution containing fat globule membrane proteins;

step II: mixing ethyl acetate solution of catechin raw material with buffer solution containing fat globule membrane protein, and stirring to obtain suspension;

step III: the solid in the suspension was isolated.

In certain embodiments, the pretreatment is to first dissolve the catechin raw material in ethyl acetate, and then mix the ethyl acetate solution containing the catechin raw material with a buffer solution of fat globule membrane proteins, embedding the catechins with the fat globule membrane proteins. The use of the ethyl acetate can better shield the color and the bitter taste of the catechin raw material, ensure the product quality and cannot damage the performance of the catechin raw material; the fat globule membrane protein can effectively embed catechin in ethyl acetate, so that the catechin is more stable in products, in addition, the fat globule membrane protein is selected for embedding, so that the catechin can resist the corrosion of gastric acid and bile in human bodies, and meanwhile, the fat globule membrane protein is a functional protein and has certain help in the aspects of intelligence development of children and the like.

The amount of ethyl acetate is not limited, and the catechin raw material can be dissolved. In certain embodiments, the ethyl acetate solution of the catechin feedstock is prepared by a process comprising the steps of: the catechin raw material is mixed with ethyl acetate and stirred well (e.g., with a magnetic stirrer) until the catechin raw material is completely dissolved. In certain embodiments, the concentration of catechins in the ethyl acetate solution is between 0.08% and 0.11% (e.g., 0.1%) (w/w).

In certain embodiments, the catechin feedstock in step I is a commercially available catechin powder.

In certain embodiments, the Catechin feedstock in step I comprises one or more of Catechin (Catechin, C), Epicatechin (EC), Epigallocatechin (EGC), Epicatechin gallate (ECG), Epigallocatechin gallate (EGCG).

The catechin used in the pretreatment method of the present invention may be catechin extracted from green tea, or catechin extracted from lycium barbarum tea, black tea, or the like. Because various components in common tea are difficult to separate and purify, different manufacturers have different product specifications and purities, the highest total catechin content can reach about 98 percent, and the tea has darker color and bitter taste. It will be appreciated by those skilled in the art that the catechin raw material should be selected as highly pure as possible in the present invention.

The buffer solution of the lipoglobin membrane protein can be prepared by a method comprising the following steps: providing a phosphate buffer solution, and dissolving the fat globule membrane protein in the phosphate buffer solution. In certain embodiments, the phosphate buffered solution has a pH of 6.9 to 7.1 (e.g., 7.0). In certain embodiments, the phosphate buffer solution has a concentration of 4 to 6mM (e.g., 5 mM). In the present invention, the concentration of the phosphoric acid buffer solution refers to the concentration of all phosphate ions contained in the solution. In certain embodiments, the concentration of the fat globule membrane protein in the fat globule membrane protein buffer solution is between 0.10% and 1.50% (w/v).

The inventors found that when the mass of the fat globule membrane protein is 3 to 5.5 times of the mass of the catechin raw material, the catechin can be completely embedded in the fat globule membrane protein. Thus, in certain embodiments, step I comprises: preparing a buffer solution from the fat globule membrane protein with a weight 3-5.5 times (for example, 3 times, 3.5 times, 4 times, 4.5 times, 5 times or 5.5 times) of the weight of the catechin raw material.

Furthermore, when the temperature of the fat globule membrane protein buffer solution is 50-60 ℃, the viscosity of the fat globule membrane protein is higher, which is beneficial to the embedding effect; more preferably, the temperature of the fat globule membrane protein solution may be 55-59 ℃. Therefore, in certain embodiments, the temperature of the buffer solution containing the lipocorm protein provided in the step I is 50-60 ℃ (preferably 55-59 ℃).

In certain embodiments, step II comprises: mixing ethyl acetate solution of catechin raw material with buffer solution containing fat globule membrane protein, maintaining the temperature at 50-60 ℃, preferably at 55-59 ℃, and stirring to obtain white suspension.

In some embodiments, the stirring is carried out for 2-2.5 hours, and the fat globule membrane protein can be fully fused with the catechin within the stirring time range, so that the embedding effect is improved.

In certain embodiments, the ethyl acetate solution of the catechin raw material is mixed with the buffer solution comprising the fat globule membrane protein in a weight ratio of 1:8.5 to 1:9.5 (e.g., 1: 9).

In certain embodiments, step II further comprises: homogenizing the suspension; in certain embodiments, homogenization is performed using a high pressure homogenizer; in certain embodiments, homogenizing under conditions of 60 to 80MPa (e.g., 70 MPa); in certain embodiments, homogenization may be performed one or more times.

After step II, the solid in the suspension is isolated. In certain embodiments, the solid in the suspension is separated from the liquid in step III by rotary evaporation and filtration.

In certain embodiments, step III comprises: subjecting the suspension to rotary evaporation (e.g., rotary evaporation at 40-45 deg.C), cooling (e.g., cooling to room temperature), standing (e.g., standing overnight), filtering to obtain a precipitate, and drying the precipitate (e.g., drying at a temperature of 50 deg.C or lower) to obtain a pretreated catechin raw material.

In certain embodiments, the process of the present invention for pretreating a catechin feedstock comprises the steps of: dissolving catechin in ethyl acetate at a concentration of 0.1% (w/w), stirring with a magnetic stirrer fully until catechin is completely dissolved, mixing catechin solution and fat globule membrane protein buffer solution fully according to a weight ratio of 1:9, homogenizing for 1 time under 70MPa by using a high-pressure homogenizer, performing rotary evaporation at 40 ℃ to remove ethyl acetate, cooling, standing, filtering, and drying to obtain pretreated catechin.

In certain embodiments, the weight of the pretreated catechin is increased as compared to the weight of the catechin feedstock before pretreatment, e.g., the weight of the pretreated catechin is typically 3.0 to 4.5 times the weight of the catechin feedstock before treatment. In certain embodiments, the pre-treated catechin raw material comprises tea polyphenols and theaflavins and other active substances contained in tea leaves, which may be included in the pre-treated catechins after treatment.

In one aspect, the present application relates to a catechin feedstock after being subjected to the above-described process. In certain embodiments, the pretreated catechin feedstock is a white powder. In certain embodiments, the white powder has a catechin content of 16% to 17%.

In addition to being used in the food field as a food additive or a functional dietary supplement, catechins can also be used in the pharmaceutical field as pharmaceutical intermediates (e.g., components of a herbal compound preparation). Thus, in another aspect, the present application relates to the use of a catechin raw material pretreated by the above method for preparing a food or a pharmaceutical product. In certain embodiments, the food product is a dairy product or a functional beverage, such as a milk-containing beverage, e.g., fruit juice milk.

In certain embodiments, the catechin raw material is used as a pharmaceutical intermediate, a functional dietary supplement, or a food additive.

In one aspect, the present application relates to a food product (e.g., a dairy product, such as a milk-containing beverage, such as fruit juice milk) comprising or made from a composition comprising a catechin raw material pretreated by the above-described method.

In certain embodiments, the food product is a fruit juice milk made from a composition comprising: catechin raw materials pretreated by the method, fruit juice or fruit pulp, raw milk, cane sugar, a stabilizer, an emulsifier and water.

In certain embodiments, the catechin raw material pretreated by the above method accounts for 0.04 wt% to 0.09 wt% (e.g., 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, or 0.09 wt%) of the total amount of raw materials of the fruit juice milk, in terms of mass percentage, within which range the pretreated catechin raw material can be more effectively absorbed by the human body and the weight control effect is more excellent.

In the fruit juice milk of the present invention, the fruit juice or fruit pulp as a raw material may be obtained by purchase. In certain embodiments, the fruit juice or pulp is obtained by treating fruit by: screening fruits, pretreating, crushing, juicing (pulping), filtering, concentrating and freezing. In certain embodiments, the juice or pulp has a solids content of 7 wt% to 29 wt% (e.g., 7 wt% to 10 wt%, 10 wt% to 20 wt%, or 20 wt% to 29 wt%). In certain embodiments, the juice or pulp has the following taste: banana, apple, strawberry, mango or cantaloupe flavour. In certain embodiments, the fruit juice or fruit pulp comprises 0.3 wt% to 1.2 wt% (e.g., 0.3 wt% to 0.6 wt%, 0.6 wt% to 0.9 wt%, or 0.9 wt% to 1.2 wt%) of the total raw material of the fruit juice milk, on a mass percent basis.

Among the raw material components, the pretreated catechin can effectively act on a human body to achieve the effective absorption dose of the human body; the fruit juice or fruit pulp raw material can effectively improve the whole fruit juice flavor of the product, and the dosage of the fruit juice or fruit pulp raw material meets the requirements of regulations.

The addition of the raw milk can effectively improve the taste and milk flavor of the product. The raw milk can be milk or milk powder; the milk is fresh milk or reconstituted milk which meets the acquisition standard of fresh milk in China, and can be full-fat milk, partially-defatted low-fat milk or completely-defatted milk; the milk powder may be whole milk powder, skim milk powder or partially skim milk powder. In certain embodiments, the raw milk is milk, which is added in an amount of 80 wt% to 90 wt% (e.g., 80 wt% to 82 wt%, 82 wt% to 85 wt%, or 85 wt% to 90 wt%) of the total raw material of the juice milk, in mass percentage.

The optimal sweetness of the product can be achieved by adding a certain amount of sucrose. In certain embodiments, sucrose is added in an amount ranging from 3 wt% to 5 wt% based on the total raw material of the fruit juice milk, in mass percent.

The addition of the stabilizer can effectively improve the stability of the product and avoid the adverse phenomena of layering, flocculation and the like. In certain embodiments, the stabilizing agent is selected from one or more of carrageenan, microcrystalline cellulose (MCC), gellan gum, xanthan gum, sodium alginate. In certain embodiments, the stabilizer is added in an amount ranging from 0.26 wt% to 0.5 wt% (e.g., 0.26 wt% to 0.3 wt%, 0.3 wt% to 0.4 wt%, or 0.4 wt% to 0.5 wt%) of the total raw material of the juice milk, in mass percent. In certain preferred embodiments, the stabilizer comprises gellan gum and MCC, wherein gellan gum is added in an amount of 0.02 wt% to 0.05 wt% (e.g., 0.02 wt% to 0.035 wt% or 0.035 wt% to 0.05 wt%) and MCC is added in an amount of 0.15 wt% to 0.4 wt% (e.g., 0.15 wt% to 0.3 wt% or 0.3 wt% to 0.4 wt%) of the total raw material of the fruit juice milk.

The addition of the emulsifier can avoid the phenomena of floating oil, precipitation and the like caused by the combination of the fruit juice or the fruit pulp raw material and the milk. In certain embodiments, the emulsifier is selected from one or more of sucrose fatty acid esters, glyceryl monostearate (monoglyceride), and glyceryl distearate (diglyceride). In certain embodiments, the emulsifier is added in an amount of 0.03 wt% to 0.12 wt% (e.g., 0.06 wt% to 0.1 wt%) of the total raw material of the juice milk, in mass percent, and in this mass ratio range, the emulsifier can more effectively entrap the oily components of the juice or pulp raw material and further enhance the emulsifying effect of the product by combining the water-based emulsifier with the hydrophilic components of the milk. In some embodiments, the emulsifier is sucrose fatty acid ester, and is added in an amount of 0.03 wt% to 0.08 wt% based on the total amount of raw materials of the fruit juice milk. In certain embodiments, the emulsifier is monoglyceride added in an amount of 0.05 wt% to 0.09 wt% of the total raw material of the juice milk. In certain embodiments, the emulsifier is sucrose fatty acid ester and monoglyceride; in certain embodiments, the sucrose fatty acid ester is added in an amount of 0.03 wt% to 0.06 wt% and the monoglyceride is added in an amount of 0.05 wt% to 0.09 wt% based on the total amount of the raw materials of the fruit juice milk.

In certain embodiments, the total amount of stabilizer and emulsifier added is 0.2 wt% to 0.6 wt% (e.g., 0.2 wt% to 0.4 wt% or 0.4 wt% to 0.6 wt%) of the total raw material of the juice milk, on a mass percent basis.

In certain embodiments, the raw material composition of the fruit juice milk of the present invention further comprises one or more of a flavoring (e.g., fruit juice flavor), a nutrient (e.g., vitamin), a sweetener, a buffer salt. In certain embodiments, the flavoring essence is added in an amount of 0.02 wt% to 0.1 wt% of the total raw material of the fruit juice milk, on a mass percentage basis. In certain embodiments, the nutrients are added in an amount ranging from 0.05 wt% to 0.1 wt% of the total raw material of the juice milk, in mass percent. In certain embodiments, the sweetener is added in an amount of 0.01 wt% to 0.05 wt% of the total raw material of the fruit juice milk; in certain embodiments, the buffer salt is added in an amount ranging from 0.1 wt% to 0.8 wt% of the total raw material of the juice milk, in mass percent.

In certain preferred embodiments, the fruit juice milk of the present invention is prepared from a composition comprising:

in yet another aspect, the present application is directed to a method of preparing juice milk comprising the steps of:

step 1: pretreating catechin raw materials by the pretreatment method;

step 2: mixing the juice or pulp with other materials to obtain a substrate feed solution, the other materials including but not limited to: pretreated catechin raw materials, cane sugar, a stabilizer, an emulsifier, raw milk and water; optionally, adjusting the pH of the juice or pulp to neutral prior to mixing;

and step 3: homogenizing the substrate liquid, sterilizing, and cooling to obtain fruit juice milk.

According to the method, by carrying out a specific pretreatment process on catechin, the obtained pretreated catechin can shield the color and the bitter taste of the catechin to a great extent, and the catechin is further added into a base material to produce the fruit juice milk, so that the influence of the color and the bitter taste of the catechin on the fruit juice milk product can be eliminated or reduced to the greatest extent, the product quality is ensured, and the product can have the effect of weight control. In addition, the catechin treated by the specific process can improve the stability of fruit juice milk products and prolong the shelf life of the products.

After the catechin raw material is pretreated, the catechin raw material is mixed with fruit juice or fruit pulp, cane sugar, stabilizing agent, emulsifying agent, raw milk, water and other raw materials to prepare substrate feed liquid. Optionally, the raw materials used to formulate the substrate liquor may also include one or more of flavorants (e.g., fruit juice flavors), nutrients (e.g., vitamins), sweeteners, buffer salts. In certain embodiments, the substrate feed solution is formulated using the raw material composition of fruit juice milk described in detail above.

In step 2, when the fruit juice or fruit pulp raw material is acidic, the fruit juice or fruit pulp can be adjusted to be neutral, so as to avoid protein denaturation in the milk caused by low pH value of the fruit juice or fruit pulp raw material, and further improve the stability of the product.

In certain embodiments, the mixing described in step 2 is carried out at a temperature of 50 to 60 ℃. In some embodiments, the mixing is by stirring for 15 to 30 minutes.

In certain embodiments, the raw milk is milk, and step 2 comprises: heating milk to 50-60 ℃, adding the pretreated catechin, the neutral fruit juice or fruit pulp, sucrose, a stabilizer, an emulsifier and other raw materials except water, adding water to a constant volume, and circularly stirring for 15-30 minutes to obtain the prepared substrate feed liquid.

In certain embodiments, the raw milk is milk powder, and step 2 comprises: dissolving milk powder in partial water (such as water accounting for 40-60% of the total water), heating to 50-60 ℃, adding the pretreated catechin, the neutral fruit juice or fruit pulp, sucrose, a stabilizer, an emulsifier and other raw materials except water, adding the rest water to a constant volume, and circularly stirring for 15-30 minutes to obtain the prepared substrate feed liquid.

And (3) homogenizing the prepared substrate material liquid, wherein in certain embodiments, the homogenization is carried out at the temperature of 55-70 ℃ and/or under the condition of 180-220 Bar, and the material liquid can have better stability.

And (3) sterilizing the homogenized substrate liquid, wherein in some embodiments, the sterilization is performed at a temperature of 112-140 ℃, and preferably for 4-15 seconds.

And cooling the sterilized substrate liquid (for example, cooling to below 4 ℃), and filling after the substrate liquid is qualified.

The fruit juice milk prepared by the method has good tissue state, pure flavor, good fruit juice milk flavor and good stability, can be stored for more than 45 days at low temperature (2-6 ℃) without unacceptable layering, sedimentation and fat floating.

In yet another aspect, the present application also relates to a juice milk made by the method of making juice milk as described above.

If no special description is provided, all the raw materials can be obtained commercially, and the performance indexes of all the raw materials meet the requirements of related quality standards.

The packaging form of the product in the invention has no specific requirement, and can adopt the common packaging form of fruit juice milk on the market at present. For example, the product of the present invention may be packaged in a roof box or in a plastic bottle such as PET, HDPE, BOPP, etc.

The equipment used in the production process of the present invention can adopt the equipment and the related technology which are well known in the art, and the detailed description of the production equipment and the filling process is omitted.

Any range recited herein is intended to include the endpoints and any number between the endpoints and any subrange subsumed therein or defined therein.

Definition of terms

In the present invention, unless otherwise specified, scientific and technical terms used herein have the meanings that are commonly understood by those skilled in the art. Also, the laboratory procedures referred to herein are all conventional procedures widely used in the corresponding field. Meanwhile, in order to better understand the present invention, the definitions and explanations of related terms are provided below.

The term "catechin" as used herein refers to catechins having a 2-phenylbenzodihydropyran structure, including, but not limited to, catechin, Epicatechin (EC), Epigallocatechin (EGC), Epicatechin gallate (ECG), Epigallocatechin gallate (EGCG), and the like, unless otherwise specified. Catechin can be obtained by extraction from natural plant such as tea leaf, but not limited thereto.

As used herein, the term "catechin raw material" refers to a catechin product that may be used as a raw material for food, pharmaceutical, or daily chemical products, and contains one or more catechins, and may contain other components such as tea polyphenols, theaflavins, caffeine, moisture, and the like. The commercial catechin raw materials are mostly powder products, including but not limited to EGCG (epigallocatechin gallate) series products (such as EGCG98, EGCG95, EGCG90) produced by Jiangsu De and Biotech limited.

As used herein, the term "fat globule membrane protein" refers to a protein in milk (e.g., cow milk) that binds to the surface of Milk Fat Globules (MFG), also known as "milk fat globule membrane proteins (MFGPs)". The milk fat globules mean spherical fat aggregates which are dispersed in milk and have the diameter of about 0.2-15 μm, the main body of the fat aggregates is fat, and the fat aggregates comprise triglyceride at the center and phospholipid (comprising glycerophospholipid, sphingomyelin and the like) which wraps the outer side of the triglyceride to form a membrane layer (namely a milk fat globule membrane). The fat globule membrane protein mainly comprises milk proteins such as Xanthine Oxidoreductase (XOR), cremophil protein (Btn) and milk fat globule surface growth factor 8 (MFG-E8). Commercial lipoglobin is commercially available from suppliers such as Hilmar ingredients, an exemplary product having the product designation Hilmar 7500.

Advantageous effects

The invention enables the color and the bitter taste of the catechin to be shielded by pretreating the catechin raw material. The pretreated catechin raw material is added into food such as fruit juice milk, etc., so that the catechin content in the food can be increased and the food has the effect of controlling body weight without influencing the color and taste of the food. Particularly, the catechin raw material after pretreatment is added into the fruit juice milk, so that the stability of the product is improved, and the risk of poor stability of the product in shelf life is reduced.

The invention also provides the fruit juice milk containing the catechin, which has unique flavor, fresh mouthfeel and good stability, also has the effect of controlling weight, can be used as functional food meeting the requirements of modern people, and has wide application prospect.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.

The catechin raw materials used in the following examples were purchased from Jiangsu De and Biotech Co., Ltd, were dark brown powders, had no toxic side effects, and were bitter in taste, and had a catechin content of about 98%. The fat globule membrane proteins used in the examples below were all purchased from Hilmar corporation, USA, Cat. Hilmar7500, Hilmar ingredients.

Example 1

1. The fruit juice milk comprises the following raw materials in percentage by mass:

2. the preparation method of the fruit juice milk comprises the following steps:

1) pretreating a catechin raw material:

dissolving catechin raw material in ethyl acetate at a ratio of 0.1% (w/w) to obtain ethyl acetate solution. Fat globule membrane protein 3 times the mass of catechin raw material was dissolved in 5mM phosphate buffer solution of pH 7.0 at a concentration of 0.12% (w/v). Adding ethyl acetate solution into 55 deg.C fat globule membrane protein buffer solution at a weight ratio of 1:9, stirring at 55 deg.C for 2 hr to obtain white suspension, homogenizing under 70MPa for 1 time, rotary evaporating at 40 deg.C to remove ethyl acetate, cooling to room temperature, standing overnight, filtering to obtain precipitate, and drying at below 50 deg.C to obtain pretreated catechin raw material.

The pretreated catechin raw material is white powder without peculiar smell. The catechin content in the product is 16.67% + -0.27% (n is 3, and n is the statistical sample volume).

2) Adjusting the fruit juice raw material to neutral pH:

adjusting the pH value of the juice raw material to be neutral by using baking soda;

3) heating the raw milk to 50-60 ℃, adding a stabilizer, an emulsifier and a sweetener which are uniformly mixed in advance, adding the pretreated catechin raw material and the fruit juice raw material with the pH value adjusted to be neutral, adding water to a constant volume, and circularly stirring for 30 minutes; adding strawberry essence to obtain a prepared substrate feed liquid;

4) homogenizing: homogenizing the prepared substrate material liquid at 60 deg.C under 180 bar;

5) and (3) sterilization: sterilizing the homogenized feed liquid at 112 deg.C for 4 s;

6) and (3) cooling: and (4) rapidly cooling the sterilized feed liquid to 4 ℃, filling, and leaving the factory after the feed liquid is qualified.

Example 2

1. The fruit juice milk comprises the following raw materials in percentage by mass:

2. the preparation method of the fruit juice milk comprises the following steps:

1) pretreating a catechin raw material:

the pretreatment was carried out as in example 1.

2) The raw milk received was preheated to 55 ℃ and defatted in a separator with a fat content of < 0.6%. Heating the skim milk to 50-60 ℃, adding a stabilizer, an emulsifier and sucrose which are uniformly mixed in advance, adding the pretreated catechin raw material and the banana pulp, adding water to a constant volume, and circularly stirring for 30 minutes; adding banana essence to obtain a prepared substrate feed liquid;

3) homogenizing: homogenizing the prepared substrate material liquid at 60 deg.C under 200 bar;

4) and (3) sterilization: sterilizing the homogenized feed liquid at 140 deg.C for 15 s;

5) and (3) cooling: and (4) rapidly cooling the sterilized feed liquid to 4 ℃, filling, and leaving the factory after the feed liquid is qualified.

Example 3

1. The fruit juice milk comprises the following raw materials in percentage by mass:

2. the preparation method of the fruit juice milk comprises the following steps:

1) pretreating a catechin raw material:

the pretreatment was carried out as in example 1.

2) Heating the raw milk to 50-60 ℃, adding a stabilizer, an emulsifier and a sweetener which are uniformly mixed in advance, adding the pretreated catechin raw material and mango pulp, adding water to a constant volume, and circularly stirring for 30 minutes; adding mango essence to obtain a prepared substrate feed liquid;

3) homogenizing: homogenizing the prepared substrate material liquid at 60 deg.C and 220 bar;

4) and (3) sterilization: sterilizing the homogenized feed liquid at 132 deg.C for 6 s;

5) and (3) cooling: and (4) rapidly cooling the sterilized feed liquid to 4 ℃, filling, and leaving the factory after the feed liquid is qualified.

Comparative example 1

In this comparative example, juice milk was prepared as a comparative sample without adding catechin as a raw material and under the same other formulation and process conditions as in example 1.

Comparative example 2

In this comparative example, a comparative fruit juice milk was prepared by adding a catechin raw material without pretreating the catechin raw material, and by using the same formulation and process conditions as those in example 2.

Experimental example 1 verification of weight control efficacy of fruit juice milk product

30 female mice with a weight of about 22g were selected and randomly divided into 6 groups for gastric lavage, samples of examples 1 to 3, comparative examples 1 to 2 and control experiments (physiological saline only) were quantitatively perfused into the mice each day, and the body weights of the mice were weighed once every 2 weeks and monitored for 8 weeks, with the specific results shown in table 1.

TABLE 1 mouse weight control test results (unit: g)

As can be seen from the above table, the body weight of the mice of the samples of the gavage examples 1-3 and the comparative example 2 is obviously reduced within 8 weeks, while the body weight of the mice of the sample of the gavage comparative example 1 is obviously increased within 8 weeks, and the body weight of the mice of the gavage normal saline is relatively stable within 8 weeks.

The results show that: the fruit juice milk added with catechin has the effect of controlling weight.

Experimental example 2 sensory evaluation of fruit juice milk products

In this experimental example, sensory evaluation tests were performed on the fruit juice milks of examples 1 to 3 and comparative examples 1 to 2, and an evaluation group consisting of 30 research and development engineers performed sensory evaluation on the fruit juice milk samples, wherein the evaluation results are shown in table 2 and table 3, respectively.

TABLE 2 Fine rules of scoring for sensory evaluation of fruit juice milk products

TABLE 3 results of sensory evaluation of fruit juice milk products

	Color	Taste of the product	Tissue state
				Example 1	9	9	8
Example 2	8	8	8
				Example 3	8	9	8
Comparative example 1	9	9	8
				Comparative example 2	8	5	5

As can be seen from Table 3, examples 1 to 3 have no significant difference in color from the samples of comparative examples 1 to 2, but the samples of examples 1 to 3 are significantly superior to comparative example 2 in taste and texture, and the evaluation group reflects that comparative example 2 has severe bitterness and astringency compared with the samples of examples 1 to 3.

The results show that: the pretreated catechin raw material does not have adverse effects on the taste and the tissue state of the fruit juice milk; in contrast, the untreated catechin raw material may give severe bitterness and astringency to the juice milk and deteriorate the texture state of the juice milk.

Experimental example 3 shelf life stability testing of fruit juice milk products

In the experimental example, the shelf life stability of the fruit juice milk of the examples 1 to 3 and the comparative examples 1 to 2 was tested under the following conditions: the samples were stored at room temperature for 6 months and the results are shown in Table 4.

TABLE 4 shelf-life stability test results for fruit juice milk products

	pH value	Centrifugal precipitation Rate (%)	Stability factor R
				Example 1	6.828	0.6	0.832
Example 2	6.840	0.65	0.828
				Example 3	6.853	0.69	0.812
Comparative example 1	6.868	0.7	0.8
				Comparative example 2	6.838	0.8	0.72

As can be seen from Table 4, the pH values of the samples of examples 1 to 3 and the samples of comparative examples 1 to 2 are both 6.8 to 6.9, the centrifugal precipitation rates of examples 1 to 3 are 0.6 to 0.7 percent, the centrifugal precipitation rates of comparative examples 1 to 2 are 0.7 to 0.8 percent, and the centrifugal precipitation rates of the samples of examples 1 to 3 are superior to those of comparative examples 1 to 2; the stability factor of the samples of comparative examples 1-3 is between 0.8-0.85, and the stability factor of the samples of comparative examples 1-2 is between 0.7-0.8, which shows that the stability of the samples of examples 1-3 is better than that of comparative examples 1-2.

The results show that: the pretreated catechin raw material is added, so that the stability of the fruit juice milk product is improved to a certain extent.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (10)

1. A method for pretreating catechin raw materials comprises the following steps:

step I: providing an ethyl acetate solution of a catechin raw material, and providing a buffer solution containing fat globule membrane proteins;

step II: mixing ethyl acetate solution of catechin raw material with buffer solution containing fat globule membrane protein, and stirring to obtain suspension;

step III: the solid in the suspension was isolated.

2. The method of claim 1, having one or more of the following features:

(1) the catechin raw material in the step I is commercial catechin powder;

(2) the catechin raw material in the step I comprises one or more of catechin, epicatechin, epigallocatechin, epicatechin gallate and epigallocatechin gallate;

(3) in the fat globule membrane protein buffer solution of the step I, the concentration of the fat globule membrane protein is 0.10-1.50% (w/v);

(4) the step I comprises the following steps: preparing fat globule membrane protein with the weight 3-5.5 times of that of the catechin raw material into buffer solution;

(5) the temperature of the buffer solution containing the lipocorm protein in the step I is 50-60 ℃;

(6) step II comprises the following steps: mixing an ethyl acetate solution of a catechin raw material with a buffer solution containing fat globule membrane protein, maintaining the temperature at 50-60 ℃, and stirring to obtain a white suspension;

(7) step II further comprises: homogenizing the suspension;

(8) in the step III, the solid in the suspension is separated out by carrying out rotary evaporation and filtration on the suspension;

(9) step III comprises the following steps: and performing rotary evaporation, cooling, standing and filtering on the suspension to obtain a precipitate, and drying the precipitate to obtain the pretreated catechin raw material.

3. A catechin feedstock subjected to the process of claim 1 or 2.

4. Use of the catechin raw material of claim 3 for preparing a food or a pharmaceutical;

preferably, the food product is a dairy product or a functional beverage, such as a milk-containing beverage, e.g. fruit juice milk;

preferably, the catechin raw material is used as a pharmaceutical intermediate, a functional dietary supplement or a food additive.

5. A food product (e.g. a dairy product, such as a milk-containing beverage, such as fruit juice milk) comprising the catechin-containing material of claim 3, or prepared from a composition comprising the catechin-containing material of claim 3.

6. The food product of claim 5, which is a fruit juice milk made from a composition comprising: the catechin-containing raw material, fruit juice or fruit pulp, raw milk, sucrose, stabilizer, emulsifier, water of claim 3.

7. The food product of claim 6, the composition having one or more of the following characteristics in percent by mass:

(1) the catechin raw material of claim 3 comprising 0.04 wt% to 0.09 wt% of the composition;

(2) the fruit juice or fruit pulp accounts for 0.3-1.2 wt% of the composition;

(3) the raw milk accounts for 80-90 wt% of the composition;

(4) the sucrose accounts for 3 wt% -5 wt% of the composition;

(5) the stabilizer accounts for 0.26 to 0.5 weight percent of the composition;

(6) the emulsifier accounts for 0.03-0.12 wt% of the composition;

(7) the raw milk is milk or milk powder;

(8) the stabilizer is one or more selected from carrageenan, microcrystalline cellulose, gellan gum, xanthan gum and sodium alginate;

(9) the emulsifier is selected from one or more of sucrose fatty acid ester, glyceryl monostearate and glyceryl distearate;

(10) the composition further comprises one or more of flavorants, nutrients, sweeteners, buffer salts.

8. A method for preparing fruit juice milk comprises the following steps:

step 1: pretreating a catechin raw material by the method of claim 1 or 2;

step 2: mixing the juice or pulp with other materials to obtain a substrate feed solution, the other materials including but not limited to: pretreated catechin raw materials, cane sugar, a stabilizer, an emulsifier, raw milk and water; optionally, adjusting the pH of the juice or pulp to neutral prior to mixing;

and step 3: homogenizing the substrate liquid, sterilizing, and cooling to obtain fruit juice milk.

9. The method of claim 8, having one or more of the following features:

(1) in step 2, formulating a substrate liquor using a composition as defined in claim 6 or 7;

(2) in step 2, the juice or pulp is adjusted to neutral before mixing;

(3) in the step 2, the mixing is carried out at a temperature of 50-60 ℃;

(4) in the step 2, the mixing mode is stirring for 15-30 minutes;

(5) in the step 3, homogenizing is carried out at the temperature of 55-70 ℃ and/or under the condition of 180-220 Bar;

(6) in the step 3, the sterilization is carried out at the temperature of 112-140 ℃;

(7) in the step 3, the sterilization is carried out for 4-15 seconds;

(8) in step 3, the cooling is to below 4 ℃.

10. Fruit juice milk produced by the method of claim 8 or 9.