Amino acid profile and protein quality related to canning and storage of swordfish packed in different filling media

Abstract

This study was conducted to determine the effect of canning, different filling media (olive oil, corn oil, sunflower oil and high oleic sunflower oil) and storage on the amino acid profile and protein quality in swordfish. Glutamic acid, aspartic acid and leucine are the predominant amino acids in raw swordfish, representing 35.62 % of the total amino acids. Thawing-salting caused significant losses of methionine, glycine and tyrosine. Frying caused moisture loss, resulting in higher protein and amino acid contents in fried swordfish than in raw or salted fish. The changes observed during the sterilization process depended on the amino acid and filling medium. The concentrations of some amino acids, such as methionine and glycine, decreased during heat treatment; however, the proline content increased. Slight changes in some amino acids were detected after storage of the canned swordfish for 12 months. The changes during storage were also influenced by the filling medium and varied depending on the amino acid considered. The highest scores in raw and canned swordfish were observed for histidine. The quality indices used showed that canned swordfish packed in olive oil was the highest quality product of those considered.