海参胶原纤维形态及胶原蛋白理化性质研究

Collagen Fibers Morphology and Physical and Chemical Properties of Collagen of Sea Cucumber

海参体壁除水分外主要成分是胶原蛋白,对其理化性质研究将为海参加工提供理论基础。本文以鲜活刺参为原料,通过组织学方法分析了其体壁胶原纤维特征,采用胃蛋白酶促溶法提取海参胶原蛋白,并对其理化性质进行分析。研究表明,海参体壁中以胶原纤维为主,呈网状排列,少见肌原纤维;海参胶原蛋白的紫外特征吸收峰位于235 nm处,在280 nm附近吸收峰较小;傅立叶红外光谱显示其保持三螺旋结构;聚丙烯酰胺凝胶电泳显示海参胶原蛋白分子组成为(α1)3,且不含二硫键,α1链的分子量约为135kDa;氨基酸组成以甘氨酸含量最高(33.3%),脯氨酸与羟脯氨酸含量为16.4%,符合水产胶原蛋白特征;海参胶原蛋白热收缩温度(Ts)为67.56℃,高于狭鳕鱼皮胶原蛋白,海参热变性温度(Td)为22.3℃,与狭鳕鱼皮胶原蛋白类似。

Collagen is the main component of sea cucumber body wall,and the study of its physical and chemical properties will provide theoretical basis for processing sea cucumber.The characteristics of collagen fibers of sea cucumber were analyzed by histological method and sea cucumber collagen was extracted by pepsin-solution method for analysis of their physical and chemical properties.Sea cucumber body wall was mainly composed of collagen fibers which exhibited reticular arrangement,and little myofibril was found.Ultraviolet-visible absorption spectra exhibited a maximum absorbance at 235 nm,but little absorbance near to 280 nm.FT-IR demonstrated the existence of triplehelix structure.SDS-PAGE pattern showed that the structure of sea cucumber collagen was（α1）3 which was absence of disulphide bonds,and the molecular weight of α1chain was about 135 kDa.Amino acid composition analysis indicated that the content of glycine was high（33.3%）,and the level of proline and hydroxyproline was 16.4%,in accordance with the aquatic collagen characteristics.The shrinkage temperature（Ts） of sea cucumber collagen was 67.56 ℃,higher than that of pollock skin collagen,and the denaturation temperature（Td） was 22.3 ℃,similar to that of pollock skin collagen.