Calcium is essential for living organisms. Even with an apparently sufficient intake of dietary calcium,there is some concern that inadequate calcium is absorbed by the small intestine,due to precipitation of insoluble calcium salts in the neutral to slightly basic intestinal lumen. Some studies revealed that peptides have the capacity to chelate Ca and to prevent the precipitation of insoluble calcium salts, thereby increasing the amount of soluble Ca availability for absorption across the mucosa. However,the mechanism and degree of calcium ion binding are still unclear. In this paper, the combinations between collagen polypeptide(from the enzymatic hydrolysate of channel catfish bone powder) and calcium ion were studied by measuring chelate rate. On the basis of results of single-factor experiments, the Box-Behnken central composite design and response surface method were adopted to obtain the optimum conditions for chelation. The optimal chelate conditions were determined as:chelate temperature 60 ℃,chelate pH 5. 4,chelate time 1. 5 h and ratio of collagen polypeptide to calcium 2:1 (W/W). Under the optimized conditions, the chelate rate of Ca-collagen polypeptide could reach 82.53%. The formation of Ca-collagen polypeptide chelate was confirmed by the UV-VIS and FT-IR spectra. The characterization of amino acid composition of the chelate was similar to typical collagen-like protein. This research provides a practical guideline and a theoretical basis for fully utilizing fish bone protein resources and developing the deep processed products.%以斑点叉尾(鲴)鱼骨酶解胶原多肽液和氯化钙为原料,螯合率为指标,在一定条件下制备胶原多肽螯合钙,并考察温度、pH、时间、多肽与钙的质量比对螯合率的影响.在单因素实验结果的基础上,采用Box-Behnken中心组合设计和响应面分析法,确定最佳螯合工艺条件为温度60℃、pH 5.4、时间1.5h、质量比2∶1,此条件下,螯合率达82.53％.紫外吸收和傅里叶变换红外光谱扫描的结果表明,骨胶原多肽与钙形成了螯合物,且其氨基酸组成符合典型的胶原样蛋白特征.
展开▼
