高效酶提取鸡肺明胶及其结构与性质的研究

以鸡肺为原料,通过超声辅助酶法提取明胶,采用紫外光谱法、差示扫描量热法、圆二色谱、聚丙烯酰胺凝胶电泳法、激光粒度分布法、扫描电镜等分析超声辅助酶提鸡肺明胶的结构,并研究其乳化性质,探究该法在鸡肺明胶中的应用效果。研究结果表明,与常规热水提取法相比:超声辅助酶提法的明胶得率为30.08%(鸡肺除杂后干重状态原料),是前者提取的3.43倍,提取效率也提高了2.15倍,热变性温度为90.22℃,略低于前者;两种明胶均存在胶原的特征负吸收峰,出现在229 nm处,其中超声辅助酶提明胶的无规则卷曲程度低于常规热水提取明胶。平均粒径为396 nm,颗粒减小了13.7%,多数分布在相对分子质量45000~95000之间,已基本降解为小分子亚基,表面微观结构有明显的破碎;进一步分析发现,两种明胶样品的乳化性无明显差异。因此,超声辅助酶提法可显著提高明胶提取率,有效缩短了生产周期,鸡肺明胶还可作为乳化剂用于食品工业中,该方法制备的鸡肺明胶在食品领域具有潜在的应用前景,可进一步提高肉鸡副产物的附加值。

Study on Structure and Properties of Chicken Lung Gelatin Prepared by Efficient Enzymatic Extraction

The application of ultrasound-assisted enzymatic extraction of gelatin from chicken lung was explored in this study.The structure of extracted chicken lung gelatin was investigated by ultraviolet spectroscopy,differential scanning calorimetry,circular dichroism,polyacrylamide gel electrophoresis,laser particle size distribution,scanning electron microscopy,etc.Its emulsifying property was also characterized.The yield of ultrasonic assisted enzymatic extraction was 30.08%based on the dry weight of lungs without impurity,which was 3.43 times compared with that of conventional hot water extraction.And the extraction efficiency increased by 2.15 times,while the thermal denaturation temperature slightly decreased to 90.22℃.The characteristic absorption peaks of chicken lung gelatin were observed at 229 nm in both extracted methods.The secondary structure of extracted gelatin using ultrasonic-assisted enzymatic extraction was more orderly with lower degree of random curling.The average particle size distribution of gelatin extracted by ultrasound-assisted enzymatic extraction was 396 nm,reduced by 13.7%.The gelatin molecules distributed by ultrasound assisted enzyme were mainly within 45000~95000,which suggested almost completely degradation into smaller molecular subunits.Obvious fragmentation was observed on their surface microstructures.Insignificant difference of emulsification was determined between two extracted gelatin samples.Therefore,ultrasound-assisted enzymatic extraction can significantly improve the extraction rate of gelatin and effectively shorten the production cycle.Chicken lung gelatin can also be used as an emulsifier in the food industry with a potential application prospect in the food field,which can further improve the added value of broiler by-products.