Characteristics of gelatin from lizardfish (Saurida micropectoralis) and threadfin bream (Nemipterus hexodon) skins as influenced by extraction conditions

J Food Sci Technol. 2023 Nov;60(11):2813-2824. doi: 10.1007/s13197-023-05799-9. Epub 2023 Aug 9.

Abstract

Gelatins from lizardfish and threadfin bream skins were extracted using distilled water at 45 and 60 °C and 4, 8 and 12 h. Gelatin recovered from both lizardfish and threadfin bream skins was in the range of 63.96-91.46%. As extraction temperature and duration increased, the turbidity of gelatin solution from both species increased. Gelatins isolated from either lizardfish or threadfin bream skins at 45 °C for 4 and 8 h showed the maximum bloom strength (245.03-320.85 g), which were also greater than commercial gelatin from bovine (208.55 g) (P < 0.05). The gelatin gels (6.67%, w/v) could set at 4 °C within 3 min and were able to set at room temperatures within 51.83 min. Gelatins extracted from both fish skins contained α1-, β- and γ-chains as predominant protein components. The lightness of all gelatin gels faintly declined with an increase in extraction temperature and time. Among the various production conditions explored, lizardfish/threadfin bream skin gelatin developed at 45 °C and 8 h was found to be highly comparable to commercial bovine gelatin. Based on the results obtained, gelatin from both fish species could be used as a replacement for land animal counterparts and can be used in many different food and pharmaceutical products.

Keywords: Extraction temperature; Extraction time; Gelatin; Lizardfish; Threadfin bream.