鸡蛋壳赖氨酸螯合钙的制备及其结构表征

Preparation and Characterization Calcium-lysine Chelate from Eggshells

摘要:

为提高废弃鸡蛋壳的利用率，对鸡蛋壳赖氨酸螯合钙的制备工艺进行研究，并对其结构进行表征，以开发一种新型氨基酸生物钙制剂。本文以鸡蛋壳和L-赖氨酸为原料，赖氨酸螯合钙螯合率为指标，优化鸡蛋壳赖氨酸螯合钙的制备工艺。通过单因素试验和响应面试验，考察螯合反应时间、反应温度、溶液pH和L-赖氨酸与CaCl2摩尔比等因素对赖氨酸螯合钙螯合率的影响，优化确定最佳螯合工艺为：反应时间为49 min，反应温度为70 ℃，溶液pH为8.7，L-赖氨酸与CaCl2摩尔比为2:1。在此条件下，赖氨酸螯合钙螯合率为82.84%，较柠檬酸钙和谷氨酸钙螯合率分别高3.55%和1.72%。采用红外光谱、X衍射分析了鸡蛋壳赖氨酸螯合钙的结构，结果表明L-赖氨酸中的-NH2键和-COOH键均参与了螯合反应，L-赖氨酸中氨基上的N原子和羧基上的O原子均参与了反应，因此赖氨酸与钙形成了螯合物。

Abstract:

In order to increase utilization of waste eggshells and develop a new amino acid biocalcium, the preparation technology of calcium-lysine was studied, and the structure was characterized. In this paper, eggshells and L-lysine were taken as raw materials, and the chelate rate was used as the standard. The single factor test and response surface test were applied to screen and optimize 4 factors (reaction time, reaction temperature, pH, the molar ratio of L-lysine and CaCl2) for the calcium-lysine chelating capacity. The chelating process was determined as follows: the reaction time was 49 min, the reaction temperature was 70 ℃, the pH value was 8.7, the molar ratio of L-lysine and CaCl2 was 2:1. Under the optimum conditions, the chelate rate of calcium-lysine was 82.84%, and it had 3.55% and 1.72% higher chelation rates than calcium citrate and calcium glutamate, respectively. The structure of eggshells’ calcium-lysine was characterized by FT-IR and XRD, the results showed that -NH2 and -COOH chelate reaction occurred with calcium ions, and both the N atom and the O atom participated in the reaction. The research confirmed the chelating reaction between L-lysine and CaCl2.