Physico-chemical properties and fishy odour of gelatin from seabass (Lates calcarifer) skin stored in ice

Abstract

Properties and fishy odour of gelatins from seabass skin stored in ice for different days were investigated. No differences in extraction yields of gelatins were observed when skins stored for up to 18 days were used. With increasing storage time, the gelatin obtained had the increased α-amino group content (p<0.05) with coincidental decrease in α-chain band intensity but had the decreased whiteness. Total viable count and psychrophilic bacterial count of skin increased continuously as the storage time increased. Gel strength of gelatin decreased as the skin was stored in ice for a longer time (p<0.05). Lipid oxidation took place in skin during the storage as monitored by peroxide value and thiobarbituric acid reactive substances. Fishy odour intensity of gelatin increased with the increases in volatile aldehydes and alcohols when skin stored in ice for longer time was used. Therefore, the delay of skin processing must be avoided to prevent the formation of undesirable fishy odour and the loss in properties of resulting gelatin.