Amino Acid Hydrolysate from Crab Processing Waste

Abstract

NPS standard curveVariables affecting acid hydrolyses were investigated for their efficacy in producing high quality amino acid hydrolysates from crab waste protein for its potential use in specialized animal feed and other food products. In a preliminary trial, SN HCl was found to be a suitable hydrolyzing agent based on the presence of nihydrin-positive substances. Amino acid yields from a 12 hr hydrolysis time varied from about 28-31%, increased marginally to 29-32% with 24 hr of hydrolysis, but decreased with hydrolysis time in excess of 24 hr. Depending upon hydrolysis time, approximately 42-44% of the total amino acids were essential amino acids: principally leucine, arginine, valine, and threonine. The remaining nonessential amino acid fraction was composed mainly of glutamic acid, aspartic acid and glycine.Amino acid standard solution with a strength of 2.5 uM of each amino acid/ml and a total amino acid content of 5.78 mg/mL was used to calibrate the NPS standard curve. The standard solution was diluted with water to get test samples containing 10, 20, 40, 60, 80 and 100 kg of amino acids/ml volume. One half mL of test sample was mixed with 2.5 mL of ninhydrin reagent, let stand in boiling water for 20 min; on cooling made to 13 mL volume with 50% npropanol, read at 570 nm and data used to plot the NPS standard curve.

Chemical composition and flavour characteristics of a liquid extract occurring as waste in crab (Ovalipes punctatus) processing

“…have confirmed that glutamic acid is an important component in crab species. Cysteine was found in small amounts (0.33 g kg −1 protein), in accordance with various crab species where cysteine has been reported to be present in very small amounts . Compared to Atlantic spider crab meat (0.86), and brown crab meat (0.81), O. punctatus extract had higher ratio of essential to non‐essential amino acids (0.95).…”

Chemical composition of snow crab shells (Chionoecetes opilio) Composición química del caparazón del cangrejo de las nieves (Chionoecetes opilio)

“…Jaswal (1990) reported substantially higher results for the studied amino acids in the same type of crab and Heu et al (2003) in by-products of shrimp. In Chinese mitten crab, similar content and profile was found (Chen et al, 2007).…”

Mesoporous 2‐Line Ferrihydrite by a Solution‐Phase Cooperative Assembly Process for Removal of Organic Contaminants in Air

“…Subsequently, 1 ml of sodium citrate buffer (pH 2.2) was added. The samples were injected onto the amino acid analyser ion exchange column (Beckman Sodium High Performance) 20–22. The amino acid contents in samples were determined by comparing peak areas with those obtained with an amino acid standard solution.…”