虾壳中复合钙粉的制备工艺优化及大鼠对其吸收效果的评价

Preparation of Blended Calcium Powders from Shrimp Shell and Evaluation of Its Calcium Absorption in Rats

为研究虾壳中复合钙粉的制取工艺及评价大鼠对其吸收效果,以南美白对虾虾壳为研究对象,采用胰蛋白酶-柠檬酸法制取钙粉,进而以缺钙为模型研究大鼠对复合钙粉的吸收效果。结果表明：采用胰蛋白酶-柠檬酸制取复合钙粉的最佳工艺为加酶量2.5×10~3 U/g、酶解p H 8.0、酶解时间1.5 h、酶解温度45℃,此时,蛋白水解度为57.24%;柠檬酸浓度0.35 mol/L、柠檬酸用量20 m L、处理时间1.5 h时,钙溶出率为85.78%;制取的复合钙粉中钙含量为19.6%,总氨基酸含量为18.3%。复合钙粉质地细腻,呈淡褐色,无异味。动物实验表明,从虾壳中制取的复合钙粉的大鼠钙吸收效果显著（P〈0.05）,灌胃剂量66.5 mg/（kg·d）（以钙含量及大鼠体质量计）的复合钙粉能明显提高大鼠血清钙、磷水平,促进大鼠正常生长。胰蛋白酶结合柠檬酸能有效地从虾壳中制取复合钙粉,其吸收效果优于相同钙含量的碳酸钙。

Purpose： To optimize the preparation of blended calcium powders from shrimp shell and to evaluate its calcium absorption in rats. Methods： The extraction of blended calcium powders from shrimp shell（Penaeus vannamei） by the combined use of trypsin and citric acid was investigated. Furthermore, the effects of calcium powder on growth, calcium absorption in rats was studied by establishing calcium deficiency model. Results： The optimized preparation conditions were determined as follows： initial hydrolysis with 2.5 × 10~3 U/g of trypsin at p H 8.0 and 45 ℃ for 1.5 h followed by treatment with 20 m L of 0.35 mol/L citric acid for 1.5 h. Under these conditions, the rate of proteolysis was 57.24%, and the dissolution rate of calcium was 85.78%. Furthermore, the calcium power contained 19.6% calcium and 18.3% total amino acids, which was a hazel powder with a delicate texture and without off-flavor. Animal experiments showed that the calcium powder prepared from shrimp shell significantly improved calcium absorption in rats（P〈0.05）, and that gavage dose of 66.5 mg/（kg·d）（calculate based on calcium content and the body weight of rats） could improve the contents of calcium and phosphorous in serum. Conclusion： Trypsin combined with citric acid offers a mild and effective way to extract blended calcium powder from shrimp shell, which exhibits better absorption than of Ca CO3 with the same calcium content.