鲶鱼皮明胶的功能性质分析

Functional properties of gelatin extracted from catfish skin

以鲶鱼皮明胶为研究对象,考察其持水性、起泡性和乳化性等功能性质。结果表明,随着离子强度的增大,明胶的持水性呈先增加后降低的趋势;因明胶大分子质量和亲水性使其泡沫性较吐温80差,但随浓度的增加而增加,且随时间的延长而降低。明胶的乳液呈水包油(O/W)型,其显微形态表明明胶的乳化性与吐温80相当。随着明胶浓度的增大,乳化活性由29.32上升至39.33 m^2/g,乳化稳定性却下降至19.27 min;盐溶效应有助于提升明胶的乳化活性,而盐析效应和静电作用导致乳化稳定性下降;等电点附近,乳化活性和稳定性均下降;随着温度的升高(>30℃),解吸附和聚集使其乳化活性和稳定性逐渐降低。鲶鱼皮明胶的功能性质分析为其在食品工业中的应用提供了理论指导。

The functional properties including water binding capacity,foam capacity and emulsion capacity for catfish skin gelatin were investigated in this paper.The results showed that the water binding capacity of gelatin firstly increased and then decreased with the increase of ionic strength.Due to the macromolecule and the hydrophilicity of gelatin,the foam capacity was worse than that of tween 80.The foam capacity of gelatin increased with the increase of concentration,while decreased with the time.Meanwhile,the gelatin emulsion was O/W type,and the emulsion capacity was the same with tween 80 according to the results of micro-morphology.With the increase of concentration,the emulsion activity index(EAI)of gelatin increased from 29.32 to 39.33 m 2/g,while emulsion stability index(ESI)decreased to 19.27 min.Salting-in effect benefits the increase of EAI in the gelatin,while salting-out effect and electrostatic interaction decreased ESI.Meanwhile,both EAI and ESI of gelatin decreased to the minimum value when pH was close to pI.Due to desorption and aggregation,EAI and ESI of gelatin decreased gradually when the temperature exceeding 30℃.The functional properties of catfish skin gelatin could provide the theoretical guidance for the application in food industry.