CN101077118A - Method for preparing soluble heart trefoil protein - Google Patents

Abstract

A method for preparing soluble alfalfa leaf protein belongs to the technical field of plant protein. The invention provides a method for preparing soluble edible alfalfa leaf protein by using briquetted alfalfa leaves as raw materials, crushing, adding water, enzymatically breaking the wall and mechanically breaking the wall, extracting with alkali and settling acid, centrifuging, and then extracting, decolorizing and deodorizing. method. The product obtained by the invention has good water solubility, the crude protein content is close to 80%, the amino acid types are complete and balanced, meets the WHO recommended standard, the color is slightly yellow, and basically has no grassy smell, and can be used as a good functional food protein raw material.

Description

A kind of preparation method of soluble alfalfa leaf protein

technical field

A preparation method of soluble alfalfa leaf protein, which involves a kind of briquetted alfalfa leaf as raw material, through enzymatic and mechanical wall breaking, alkali extraction and acid precipitation, centrifugal separation, and decolorization to remove fishy smell, so as to obtain soluble edible alfalfa The method for leaf protein belongs to the technical field of plant protein.

Background technique

Leaf protein is a protein concentrate (leaf protein concentration, referred to as LPC) prepared by pressing fresh green plant stems and leaves as raw materials, extracting juice, separating protein in the juice, concentrating and drying. Leaf protein has attracted much attention because of its wide source, rich nutrition, no animal cholesterol, disease prevention and treatment, anti-aging and anti-aging, physical fitness and other physiological functions. It is considered by FAO as a high-quality Food is a new type of protein resource with high development value.

Alfalfa is an excellent leguminous forage, known as the "King of forage". It has strong adaptability, many varieties, long cultivation history, wide distribution range, stable productivity, long use life, high nutritional value and good palatability. , good feeding effect of livestock and poultry and other application value. Due to the rich protein content in alfalfa, the leaf protein made from alfalfa is called alfalfa leaf protein. Leaf protein contains 18 kinds of amino acids, including 8 kinds of amino acids necessary for human body, and its composition ratio is balanced, which is basically consistent with the adult amino acid pattern recommended by the United Nations Food and Agriculture Organization, especially the content of lysine is high.

However, there are many deficiencies in the currently prepared alfalfa leaf protein. The first is that the content is not high, generally only 50% to 60%; secondly, the extraction method is mostly heating flocculation method, the protein is denatured, and the solubility is poor, so its use is limited; thirdly, the product has no decolorization and deodorization, and the color is dark green. The fishy smell is heavy, which also limits the amount and use in food. Therefore, it is mainly used for feed in China at present.

Contents of the invention

The purpose of the present invention is to provide a preparation method of soluble alfalfa leaf protein. Soluble alfalfa leaf protein has good water solubility, and after decolorization and deodorization, it can be more widely used in various food systems.

The technical scheme of the present invention: use briquette alfalfa leaves as raw material, crush, add water to enzymatically break the wall, mechanically break the wall, alkali extraction, acid precipitation, centrifugal separation, and then immerse in embankment to decolorize and remove fishy smell, so as to obtain soluble edible alfalfa leaves The process conditions for protein extraction are as follows: briquette alfalfa leaves are crushed to 40 meshes, the amount of water added by mass is 6-8 times that of the raw material alfalfa leaves, the pH value is adjusted to 4.5, cellulase is added, and the amount of enzymes added is the total amount of the reaction system. 2% to 3% of the mass (w/w), enzymolysis reaction temperature 45 ° C, reaction time 4 to 6 hours; then adjust the pH value to 7.8, use a tissue masher to beat for 3 minutes, soak and stir for 30 minutes, squeeze Squeeze the juice for 3 minutes to get the juice; then adjust the pH value to 4.0, flocculate for 5 minutes, and then centrifuge at 3000 rpm for 10 to 15 minutes to get the sediment; then use 95% ethanol to extract the color and remove the fishy smell. The amount of 95% ethanol used is 10-13 times the mass of the obtained precipitated material, the extraction temperature is 40°C-50°C, and the extraction time is 5-7 hours; then centrifuged at 1500 rpm for 3-5 minutes to obtain the precipitate; then freeze-dried to obtain soluble alfalfa leaf protein product.

Beneficial effects of the present invention: the soluble alfalfa leaf protein prepared by the present invention not only has a higher crude protein content than the common preparation method, but also has good water solubility, light color, almost no herbaceous smell, and balanced amino acids, especially lysine The content is as high as 4.83g/100g, and it is easily digested and absorbed by the human body. Therefore, it can be used as the main raw material of protein health food for the old, weak, sick and young, and has broad application prospects.

Detailed ways

Example 1

Alfalfa leaves are crushed to 40 meshes, the amount of water added is material: water=1:6, the pH value is adjusted to 4.5, the enzyme is cellulase, the enzyme amount is 2.5% (w/w), the reaction temperature is 45°C, and the reaction time is 4.5 Hours; then adjust the pH value to 7.8, use a tissue masher to beat for 3 minutes, soak and stir for 30 minutes, squeeze and squeeze the juice for 3 minutes to obtain juice; then adjust the pH value to 4.0, flocculate for 5 minutes, and then put it on a 3000 rpm/separation centrifuge Centrifuge for 12 minutes to obtain the precipitate; then use 95% ethanol to extract the color and remove the fishy smell, the amount of ethanol is as follows: ethanol=1:11, the extraction temperature is 42°C, and the extraction time is 6 hours; then centrifuge at 1500 rpm for 4.5 minutes A precipitate was obtained; and then freeze-dried to obtain a soluble alfalfa leaf protein product with a crude protein content of 78.8%.

Example 2

Alfalfa leaves are crushed to 40 meshes, the amount of water added is material: water=1:7, the pH value is adjusted to 4.5, the enzyme is cellulase, the amount of enzyme added is 3.0% (w/w), the reaction temperature is 45 ° C, and the reaction time is 5 Hours; then adjust the pH value to 7.8, use a tissue masher to beat for 3 minutes, soak and stir for 30 minutes, squeeze and squeeze the juice for 3 minutes to obtain juice; then adjust the pH value to 4.0, flocculate for 5 minutes and then put it on a 3000 rpm/separation centrifuge Centrifuge for 12 minutes to obtain the precipitate; then use 95% ethanol to decolorize and remove the fishy smell, the amount of ethanol is as follows: ethanol=1:12, the extraction temperature is 50°C, and the extraction time is 5 hours; then centrifuge at 1500 rpm for 3.5 minutes to obtain the precipitate and then freeze-dried to obtain a soluble alfalfa leaf protein product with a crude protein content of 79.2%.

Claims (1)

1, a kind of extracting method of soluble heart trefoil protein, it is characterized in that with the briquetting cloverleaf be raw material, through pulverizing, by adding water enzymolysis broken wall, mechanical breaking-wall method, alkali is carried, and acid is heavy, centrifugation, soak the dike decolouring again and remove raw meat, obtain the edible alfalfa leaf protein matter of solubility, the process conditions of extraction are: the briquetting cloverleaf was pulverized 40 orders, amount of water is 6～8 times of raw material cloverleaf in mass, adjust pH to 4.5 adds cellulase, and enzyme concentration is 2%～3% of a reaction system gross mass, 45 ℃ of enzyme digestion reaction temperature, 4～6 hours reaction time; Adjust pH to 7.8 was pulled an oar 3 minutes with tissue mashing machine again, soaking and stirring 30 minutes, and extruding is squeezed the juice and was got juice in 3 minutes; Adjust pH to 4.0 again, flocculated after 5 minutes on 3000 rev/mins of centrifuges centrifugal 10～15 minutes sediment; Removing raw meat, 95% ethanol consumption with 95% ethanol lixiviate decolouring again is 10～13 times that gained precipitates quality of material, 40 ℃～50 ℃ of extraction temperatures, extraction time 5～7 hours; Again with 1500 rev/mins centrifugal 3～5 minutes sediment; Freeze drying obtains the soluble heart trefoil protein product again.

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