Method for extracting proteins and chitin from heads and shells of prawns

Abstract

The invention discloses a method for extracting proteins and chitin from heads and shells of prawns, which uses fermentation with lactic acid bacteria to liquefy and separate the proteins in the heads and shells of the prawns and obtains the proteins by drying. Lactic acid produced in fermentation can dissolve inorganic calcium salts in the heads and shells of the prawns and transfer the inorganic calcium salts to fermentation liquor, and residue can be decolorized to give the chitin. The method comprises the following steps: (1) crushing the heads and shells of the prawns and adding water into the crushed heads and shells of the prawns; (2) adding glucose or sucrose into the crushed heads and shells of the prawns; (3) inoculating with the lactic acid bacteria; (4) keeping temperature for fermentation; and (5) after the fermentation is finished, separating the fermentation liquor from the fermentation residue, neutralizing and drying the fermentation liquor to obtain proteins, and subjecting the fermentation residual to soaking in a diluted acid and decolorization to obtain the chitin. The proteins obtained by the method has the characteristics of light fishy smell and bit flavor, excellent flavor and rich calcium lactate content and can be used in food.

Description

technical field [0001] The invention relates to the technical field of extracting protein and chitin from aquatic products, in particular to a method for extracting protein and chitin from shrimp heads and shrimp shells. Background technique [0002] For shrimps, shrimp heads and shells are rich in nutrients. For example, the shrimp heads and shells of shrimps account for about 30% of the shrimp body weight. In addition to minerals such as chitin and calcium carbonate, they also contain 7-10% protein, 2-4% oil, rich in vitamin E, astaxanthin, lutein, lecithin and other ingredients, with high nutritional value. [0003] At present, the utilization of shrimp heads and shrimp shells is mainly in two aspects: one is to produce chitin, and the other is to use self-cathepsin or exogenous protease to hydrolyze the protein therein and liquefy and separate it. However, direct production of chitin from shrimp heads and shells requires high-concentration acid and alkali treatment of r...

AI Technical Summary

Problems solved by technology

However, the direct use of shrimp heads and shells to produce chitin requires high-concentration acid and alkali to treat raw materials, which not only seriously pollutes, but also removes protein, fat, calcium, etc. as impurities, making it unusable.

The hydrolyzate obtained by protease hydrolysis also has obvious bitterness and fishy smell, and the product has poor flavor and cannot be used as the base material of other foods, but can only be used as feed. In addition, corruption is easy to occur during the hydrolysis process, and protease is added. also increased production costs

[0004] At present, there are no similar reports on the use of lactic acid bacteria to ferment shrimp heads and shells in China. Although there are a small number of research reports in this area abroad, they mainly use the properties of lactic acid bacteria fermentation to produce a large amount of lactic acid, which greatly reduces the pH value of shrimp shells. The purpose of anti-corrosion, so that the raw materials can be stored at room temperature for a long time, which is convenient for use as silage for animals. In addition, the protein is liquefied and separated during the fermentation process by lactic acid bacteria fermentation. Lactic acid dissolves the calcium in the shell. Since the shell has been decalcified, It is easier to use the filtered residue to produce chitin