Molecular characteristics and properties of gelatin from skin of seabass with different sizes

Abstract

Gelatin was extracted from the skin of seabass (Lutes calcarifer) with different average sizes (2, 4 and 6 kg/fish), termed G2, G4 and G6, respectively and their characteristics and functional properties were determined. Yields of G2, G4 and G6 were 38.22, 40.50 and 43.48% (based on dry weight), respectively. G2 contained cc-chains as dominant component, whilst G4 and G6 comprised alpha-, beta- and gamma-chains with a larger content of high MW cross-links. All gelatins had the similar imino acid (hydroxyproline and proline) content. Net charge of G2, G4 and G6 became zero at pH of 6.73, 6.41 and 7.12, respectively. Amongst all gelatin samples, G6 exhibited the highest gel strength (321.5g) (p < 0.05), but had the lowest turbidity (p < 0.05). Gels of G6 sample had the lower L*-value but higher a*-, b*- and Delta E*-value, compared with others. Gelling and melting temperatures of all gelatins were 17.09-19.01 and 26.92-28.85 degrees C, respectively. Furthermore, all gelatins were able to set at room temperature, regardless of size of seabass used. G6 had the shorter setting time at room temperature than others. Therefore, size of seabass, in which skin was used for gelatin extraction, had the impact on yield, composition and properties of resulting gelatin. (C) 2014 Elsevier B.V. All rights reserved

Structural properties of gelatin extracted from croaker fish (Johnius sp) skin waste

“…With increase in temperature and time of extraction, destabilization of bonds between α-chains of the native collagen molecules occurs. [4] This results in higher recovery of gelatin. In the present study, a temperature of 85°C for 60 min yielded 7.15%.…”

“…[17] But at the same time, the properties such as bloom value, viscosity and colour were found to diminish. [4,17] The yield of gelatin from acid and alkali pre-treated skins of bigeye snapper, tiger-toothed croaker, and sin croaker was 4, 7.56, and 14.3%, respectively. [13,14,25] Mohtar et al [10] reported 17.6% of yield from hoki skins pre-treated with 0.75 M NaCl.…”

“…[32] Similarly, the bloom strength of gelatin from the skin of seabass was found to be related with size of skin used for extraction. [4] Gelatin from big size skin yields higher bloom value. The bloom values of gelatin extracted from the skins of splendid squid and clown feather back after acid and alkali pre-treatment at 80°C were 85 g and 140 g, respectively.…”

“…The smaller voids indicate the uniform distribution of water in the fine and ordered matrix. [4,23] Texture profile analysis (TPA)…”

“…[1][2][3] In the food industry, gelatin has been widely used as an ingredient to improve the elasticity, consistency, and stability of foods due to its gelling property and surface active behavior. [4] In recent years, the application of gelatin in functional food formulation and novel product development is gaining importance. The thermal and rheological properties of gelatin determine its uses in various food systems.…”