阅读说明：本技术 一种通过介孔材料固定化酶制备茶多酚酯化茶籽油的方法 (Method for preparing tea polyphenol esterified tea seed oil by mesoporous material immobilized enzyme ) 是由 罗水忠 郑志 潘利华 钟昔阳 王一丹 贾永京 于 2020-06-04 设计创作，主要内容包括：一种通过介孔材料固定化酶制备茶多酚酯化茶籽油的方法,包括：(1)制作脱胶和脱蜡后的茶籽油、(2)介孔材料的清洗、(3)制作介孔材料固定化酶、(4)制备茶多酚乳化溶液、(5)固定化酶催化茶多酚酯化茶籽油。本发明制备的茶多酚酯化茶籽油,用于食品制作与加工,可以降低产品的氧化程度,延长产品货架期。(A method for preparing tea polyphenol esterified tea seed oil by mesoporous material immobilized enzyme comprises the following steps: (1) preparing degummed and dewaxed tea seed oil, (2) cleaning a mesoporous material, (3) preparing a mesoporous material immobilized enzyme, (4) preparing a tea polyphenol emulsified solution, and (5) catalyzing the tea polyphenol esterified tea seed oil by the immobilized enzyme. The tea polyphenol esterified tea seed oil prepared by the invention is used for food preparation and processing, can reduce the oxidation degree of products and prolong the shelf life of the products.)

1. A method for preparing tea polyphenol esterified tea seed oil by mesoporous material immobilized enzyme is characterized by comprising the following steps: comprises the following steps:

step 1: removing impurities from oil tea seed kernel, and squeezing oil with oil press; centrifuging the pressed grease at 7000-9000r/min for 8-10min, and collecting the upper oil layer to obtain crude oil; adding purified water 4-6% of the crude oil, and stirring at 70-72 deg.C in water bath for 30-45min at a speed of 30-60 r/min; centrifuging at 7000-9000r/min for 4-7min, and collecting the upper oil layer to obtain degummed crude oil; placing the degummed crude oil at 0-6 ℃ for 10-15 h, taking out, centrifuging at 4000-;

step 2: putting the mesoporous material into a cleaning tank, and then injecting purified water into the cleaning tank to enable the purified water to submerge the mesoporous material; the temperature of the purified water is 50-75 ℃; in the cleaning process, starting ultrasonic treatment once every 8-12min, wherein the ultrasonic frequency is 25-35 KHz, and the power density is 0.4-0.5W/cm²The treatment time is 1.5-3.0 min each time; co-processing for 2-4 h;

and step 3: mixing lipase, mesoporous material and purified water according to a mass ratio of 20-25: 45-60: 800-1200, then putting the mixture into a microwave oven, and controlling the frequency to be 2450MHz and the radiation intensity to be 0.2-0.5w/cm²Treating for 60-90s in a vacuum microwave environment, centrifuging for 4-6min at 3000-;

and 4, step 4: mixing an emulsifier and purified water according to the mass ratio of 5-10:100, putting the mixture into an emulsifier, treating the mixture for 10-15min at the rotating speed of 8000-; mixing tea polyphenol with the exhausted emulsion according to the mass ratio of 1:8-10 to obtain a tea polyphenol emulsion solution;

and 5: mixing the tea polyphenol emulsified solution, the degummed and dewaxed tea seed oil and the mesoporous material immobilized enzyme according to the mass ratio of 2-10:10:0.5-1.0, placing the mixture into an enzymatic reaction device, carrying out enzymatic reaction for 30-35h at the temperature of 37-43 ℃ and the rotating speed of 10-15r/min, filtering the reaction material through a filter screen of 40-80 meshes after the enzymatic reaction is finished, and respectively collecting filtrate and filter residue; adding purified water with the volume 5-10 times of that of the filtrate into the filtrate, stirring, standing for layering, and collecting an upper oily substance; centrifuging the collected oily substance at 4000-.

2. The method for preparing the tea polyphenol esterified tea seed oil by the mesoporous material immobilized enzyme according to claim 1, which is characterized in that: the mesoporous material is silicon-based mesoporous material MCM-41 or SBA-15 with the aperture of 5-15 nm.

3. The method for preparing the tea polyphenol esterified tea seed oil by the mesoporous material immobilized enzyme according to claim 1, which is characterized in that: the lipase is in a dry powder shape, and the enzyme activity is 5000-10 ten thousand PLU/g.

4. The method for preparing the tea polyphenol esterified tea seed oil by the mesoporous material immobilized enzyme according to claim 1, which is characterized in that: the emulsifier is at least one of sorbitan monooleate, polyoxyethylene stearate, caprylic capric glyceride, polyoxyethylene sorbitan monooleate and polyoxyethylene sorbitan monolaurate.

5. The method for preparing the tea polyphenol esterified tea seed oil by the mesoporous material immobilized enzyme according to claim 1, which is characterized in that: the mass ratio of the tea polyphenol emulsified solution to the degummed and dewaxed tea seed oil to the mesoporous material immobilized enzyme is 5.5:10: 0.8.

Technical Field

The invention belongs to the technical field of grease processing, and relates to a method for preparing tea polyphenol esterified tea seed oil by using mesoporous material immobilized enzyme.

Background

Tea seed oil, also called Camellia oil, Camellia seed oil, etc., is prepared from Camellia oleifera (Camellia) of TheaceaeCamellia oleiferaAbel) is obtained from seeds of trees and is one of the oldest woody edible vegetable oils in China. The tea seed oil is golden or light yellow in color, pure in quality, clear and transparent, fragrant in smell and pure in taste, does not contain harmful substances to human bodies such as erucic acid, cholesterol, aflatoxin and the like, is rich in unsaturated fatty acid, particularly oleic acid, and the content of the unsaturated fatty acid can reach about 80 percent; tea seed oil is similar to olive oil in chemical composition and proportion, and is also called "eastern olive oil". Tea seeds have high oil smoke point and easy absorption, and have been popularized by the international food and agriculture organization as healthy edible oil. Meanwhile, the tea seed oil contains various physiologically active substances such as camellin, tocopherol and the like, and the modern Chinese medical dictionary indicates that the tea seed oil has both nutritional and medicinal values and has the effects of improving the immunity, preventing cardiovascular and cerebrovascular diseases and the like.

Tea polyphenol is a natural antioxidant mainly existing in tea leaves, and is a general name of more than 30 polyphenol compounds in tea leaves. Tea polyphenol is a good antioxidant, is green and natural compared with commonly used artificially synthesized antioxidants TBHQ and the like in edible oil sold on the market at present, and has recently attracted extensive attention from the oil industry. Tea polyphenol contains more phenolic hydroxyl groups, is easy to dissolve in water and insoluble in oil, and is directly added into an oil system, so that the appearance of a product is influenced, and the tea polyphenol is not beneficial to absorption and utilization, and waste is caused; therefore, it is usually necessary to perform esterification reaction of tea polyphenol to improve lipid solubility and avoid destruction of phenolic hydroxyl group, and then add the resulting esterified derivative of tea polyphenol to fats and oils. The enzyme method for catalyzing the esterification reaction of tea polyphenol has the remarkable characteristics of high catalysis efficiency, strong specificity, mild action condition, environmental friendliness and the like, and is the research focus in the field at present.

The application of the free enzyme is limited due to the defects of poor stability, difficult recovery, easy product mixing, difficult recycling and the like, and compared with the free enzyme, the free enzyme has the advantages of good stability, easy separation from a reaction system, repeated use, convenient storage and the like, and has wider application space. Mesoporous materials, according to the International Union of Pure and Applied Chemistry (IUPAC) regulations, refer to a class of porous materials with pore sizes between 2-50 nm. The mesoporous material as an inorganic carrier has the characteristics of large specific surface area, ordered nano-pore structure, large pore volume, narrow pore size distribution, good thermal stability and chemical stability and the like, is an excellent immobilized enzyme carrier, and is one of the hotspots of enzyme immobilization research at present.

Disclosure of Invention

The invention aims to provide a method for preparing tea polyphenol esterified tea seed oil by using mesoporous material immobilized enzyme.

In order to achieve the above objects and other related objects, the present invention provides the following technical solutions: a method for preparing tea polyphenol esterified tea seed oil by mesoporous material immobilized enzyme comprises the following steps:

step 1: removing impurities from oil tea seed kernel, and squeezing oil with oil press; centrifuging the pressed grease at 7000-9000r/min for 8-10min, and collecting the upper oil layer to obtain crude oil; adding purified water 4-6% of the crude oil, and stirring at 70-72 deg.C in water bath for 30-45min at a speed of 30-60 r/min; centrifuging at 7000-9000r/min for 4-7min, and collecting the upper oil layer to obtain degummed crude oil; placing the degummed crude oil at 0-6 ℃ for 10-15 h, taking out, centrifuging at 4000-;

step 2: putting the mesoporous material into a cleaning tank, and then injecting purified water into the cleaning tank to enable the purified water to submerge the mesoporous material; the temperature of the purified water is 50-75 ℃; in the cleaning process, starting ultrasonic treatment once every 8-12min, wherein the ultrasonic frequency is 25-35 KHz, and the power density is 0.4-0.5W/cm²The treatment time is 1.5-3.0 min each time; co-processing for 2-4 h;

and step 3: mixing lipase, mesoporous material and purified water according to a mass ratio of 20-25: 45-60: 800-1200, then putting the mixture into a microwave oven, and controlling the frequency to be 2450MHz and the radiation intensity to be 0.2-0.5w/cm²Treating for 60-90s in a vacuum microwave environment, centrifuging for 4-6min at 3000-;

and 4, step 4: mixing an emulsifier and purified water according to the mass ratio of 5-10:100, putting the mixture into an emulsifier, treating the mixture for 10-15min at the rotating speed of 8000-; mixing tea polyphenol with the exhausted emulsion according to the mass ratio of 1:8-10 to obtain a tea polyphenol emulsion solution;

and 5: mixing the tea polyphenol emulsified solution, the degummed and dewaxed tea seed oil and the mesoporous material immobilized enzyme according to the mass ratio of 2-10:10:0.5-1.0, placing the mixture into an enzymatic reaction device, carrying out enzymatic reaction for 30-35h at the temperature of 37-43 ℃ and the rotating speed of 10-15r/min, filtering the reaction material through a filter screen of 40-80 meshes after the enzymatic reaction is finished, and respectively collecting filtrate and filter residue; adding purified water with the volume 5-10 times of that of the filtrate into the filtrate, stirring, standing for layering, and collecting an upper oily substance; centrifuging the collected oily substance at 4000-.

The preferable technical scheme is as follows: the mesoporous material is silicon-based mesoporous material MCM-41 or SBA-15 with the aperture of 5-15 nm.

The preferable technical scheme is as follows: the lipase is in a dry powder shape, and the enzyme activity is 5000-10 ten thousand PLU/g.

The preferable technical scheme is as follows: the emulsifier is at least one of sorbitan monooleate, polyoxyethylene stearate, caprylic capric glyceride, polyoxyethylene sorbitan monooleate and polyoxyethylene sorbitan monolaurate.

The preferable technical scheme is as follows: the mass ratio of the tea polyphenol emulsified solution to the degummed and dewaxed tea seed oil to the mesoporous material immobilized enzyme is 5.5:10: 0.8.

Due to the application of the technical scheme, compared with the prior art, the invention has the advantages that:

1. the invention adopts ultrasonic wave to assist and clean the mesoporous material, removes impurities on the surface of the mesoporous material, cleans the surface of the mesoporous material, meets the food sanitation requirement, and improves the subsequent enzyme adsorption effect.

2. After the mesoporous material adsorbs the immobilized enzyme, the low-intensity short-time microwave treatment is adopted, so that the adsorption effect of the enzyme and the mesoporous material is enhanced.

3. According to the invention, mesoporous material is adopted to adsorb immobilized lipase, the esterification reaction is carried out on enzymatic tea polyphenol and tea seed oil to prepare the tea polyphenol esterified tea seed oil, the esterification rate of the tea polyphenol is 38-47%, and the mesoporous material adsorption immobilized lipase can be repeatedly used for 10-15 times.

4. The tea polyphenol esterified tea seed oil prepared by the invention is used for food preparation and processing, can reduce the oxidation degree of products and prolong the shelf life of the products.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.