基于鱼鳞贮藏方式改善鳙鱼鱼鳞明胶的功能特性

Effect of Fish Scale Storage Methods on Functional Properties of Gelatin from Bighead Carp(Hypophthalmichthys nobilis) Scale

鱼鳞的贮藏方式会影响鱼鳞明胶的品质,本实验研究了太阳晒干后室温贮藏、4℃贮藏、-20℃贮藏和60℃热风干燥后室温贮藏对鳙鱼鱼鳞明胶凝胶强度、乳化活性和起泡能力的影响,并通过傅里叶变换红外光谱、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和扫描电子显微镜表征经不同方式贮藏后制备得到的鱼鳞明胶的结构特性。结果表明:4种贮藏方式不会破坏明胶的分子质量分布(α链、β链和高分子聚合物)和傅里叶变换红外光谱的特征性吸收峰(酰胺A带、酰胺I带、酰胺II带和酰胺III带)。4种贮藏方式都能提升鱼鳞明胶的乳化活性和起泡能力,其中,-20℃贮藏鱼鳞1个月改善明胶乳化活性和起泡能力的效果最佳。除60℃热风干燥之外,其他贮藏方式均能改善鱼鳞明胶的凝胶强度,这可能与其相应的结构特征变化有关。相比新鲜鱼鳞和60℃热风干燥鱼鳞,太阳晒干和低温方式(4℃和-20℃)贮藏鱼鳞使得鱼鳞明胶α链、β链和高分子聚合物含量增加,酰胺A带吸收峰的波数降低,鱼鳞明胶网络结构的致密性增加。

Fish scale storage methods affect the quality of fish scale gelatin.In this study,we investigated the effect of different fish scale storage methods(storage at room temperature,4 and?20℃after sun drying,and storage at room temperature after hot air(60℃)drying)on gel strength,emulsifying activity and foaming ability of fish scale gelatin from bighead carp(Hypophthalmichthys nobilis).The structural characteristics of gelatins from fresh and stored fish scales were measured by Fourier transform infrared(FTIR)spectroscopy,sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)and scanning electron microscope(SEM).Our results indicated that none of the storage methods for fish scales destroyed the characteristic molecular mass distribution(αchain,βchain and high molecular mass polymers)and FTIR peaks(amide A,amide I,amide II and amide III)of gelatin.All storage methods,especially 1 month storage at?20℃,improved emulsifying activity and foaming ability of fish scale gelatin.All storage methods except 60℃hot air drying could enhance gel strength,which may be related to the change of structural characteristics.Compared with fresh and hot air dried samples,sun drying and low temperature storage of fish scale increased the contents ofαchain,βchain and high molecular mass polymers in fish scale gelatin,decreased the wavenumber of amide A,and made the network structure of gelatin gels more compact.