Extraction, partial characterization and evaluation of in vitro digestibility of the protein associated with the exoskeleton of white shrimp (Litopenaeus vannamei)

Abstract

The need of new food sources to satisfy human requirements forces researchers to study any possible alternative supplies. Therefore this study aimed to explore the quality and digestibility evaluation of the protein fractions obtained as a by-product of processing the shrimp exoskeleton Litopenaeus vannamei. Shrimp exoskeletons were washed, they were dried, mincedand they were brought under acid hydrolysis and alkaline hydrolysis; released proteins were then precipitated and characterized. 496 g of demineralized exoskeleton were obtained from 1 kg of shrimp shell; out of these, 376 g corresponded to chitin and 120 g corresponded to protein Total protein content was 33.80 ± 0.34 %. The digestible protein fractions were 26.7 g and 92.1 g were insoluble proteins. Of this latter fraction, the largest proportion belonged to the scleroprotein type. The amino acid profile analysis from the recovered proteins indicated that there were present nine amino acids out of the ten essential ones, being leucine the one with the highest proportion. In vitro digestibility was shown to be up to an 83.7 %. Therefore, it was possible to conclude that the recovery of digestibleproteins from shrimp exoskeleton may be useful in diet formulation.