中文摘要：

研究了酶解时间和酸法脱酰胺改性对脱植酸大豆分离蛋白肽钙离子螯合能力的影响,并对螯合物的结构特性及营养特性进行表征。结果表明：酶解240 min的肽有较好的钙结合量（57.85mg/g）,螯合物得率为28.43%,脱酰胺后钙结合量和螯合物得率分别增加到75.37 mg/g、34.55%;氨基酸分析结果表明酸性氨基酸是参与螯合物形成的重要氨基酸;相对分子质量分布实验结果说明钙离子更倾向于结合相对分子质量大于等于1 000的肽段,螯合物得率高,但相对分子质量小于等于500的肽段是获得更高钙结合量螯合物的重要肽源;红外光谱分析表明钙结合后引起肽段结构的变化,肽链羧基中的O及氨基中的N是主要配位原子;体外消化吸收模拟实验制备的肽钙螯合物有较好的胃胰酶耐受性,经消化后肽段相对分子质量几乎没有变化,钙保留率稳定在87%左右,生物利用率达81.81%。

英文摘要：

The effects of enzymolysis time and acidic deamidation modification on the calcium-binding capacity of phytate degraded soybean protein isolate peptide were studied, and the structural and nutritional properties of peptide-calcium chelate were characterized. The results showed that when enzymolysis time was 240 min, the amount of bound calcium was higher （57.85 mg/g） and the chelate yield was 28.43%. After acidic deamidation, the amount of bound calcium and chelate yield increased to 75.37 mg/g and 3455% respectively. Amino acid analysis demonstrated that acidic amino acid made the most contribution to chelation. The results of Mr distribution experiment indicated that peptide with Mr≥1 000 showed a better chelation effect with a higher chelate yield, while peptides with Mr≤500 were the main peptides when making chelation with high amount of bound calcium. Fourier transform infrared spectra expressed that oxygen atom on the carboxyl group and nitrogen atom on the amino group were primary coordination atoms, while peptide structure changed a lot. In vitro digestion and absorption simulation experiment indicated that peptide-calcium chelate had a better tolerance to pepsin and pancreatin, and the Mr of the peptide almost had no change after digestion, with calcium retention rate about 87% and bioavailability up to 81.81%.