Process for preparing chitosan and calcium citrate

Abstract

The invention relates to a process for preparing chitosan and calcium citrate by utilizing shrimp heads and shrimp shells. The process comprises the following steps of: mixing shrimp heads and shrimp shells of Penaeus vannamei Boone in a ratio of 1:3, and tearing for 5 seconds by using a tissue tearor; adding the torn shrimp heads and shrimp shells into 1mol / L solution of NaOH according to the material-liquid ratio of (1:2)-(1:4), soaking for 2 to 4 hours at the temperature of between 85 and 100 DEG C, filtering, and repeating for 2 to 4 times; adding the filtered shrimp heads and shrimp shells into 5 to 14 percent solution of citric acid according to the material-liquid ratio of (1:1.5)-(1:3), soaking for 5 to 20 hours, filtering, decolorizing, rinsing, and drying to obtain the chitosan; and adding filtrate into solution of Ca(OH)2, regulating the obtained solution until the solution is neutral, precipitating calcium citrate in the filtrate, filtering, and drying to obtain the calcium citrate. The process is simple and easy to operate, the using amount of the citric acid is reduced, and food-grade chitosan and a byproduct, namely the calcium citrate, are also obtained.

Description

technical field [0001] The invention relates to a preparation method of a polymer compound, in particular to a process for preparing chitin. Background technique [0002] my country is a big country in the cultivation of prawns. In 2010, my country exported 188,000 tons of prawns, of which Penaeus vannamei accounted for 71%. At present, my country's shrimp export is mainly based on frozen shrimp. During the processing of shrimp, a large number of waste products will be produced: shrimp heads and shrimp shells. Zhang Xianggang and others from the School of Food Science and Technology of South China Agricultural University published an article in "Modern Food Science and Technology" "Comparative Study on the Chemical Composition of Penaeus vannamei Shrimp Head and Shrimp Shell" (2009, 25: 225-229), which showed that in the shrimp head and shrimp shell of Penaeus vannamei Chitin is 3.33% and 6.67% respectively. [0003] Chitin is a natural biological polysaccharide polymer ma...

AI Technical Summary

Problems solved by technology

[0005] The invention aims at the disadvantages of the prior art, such as low utilization rate of citric acid, long soaking time, low production efficiency, etc., and the invention provides a method for producing chitin and calcium citrate