郑亚军 史攀琪 王国龙 王贤 李艳 刘乐 李桂峰

摘  要：为提高椰子加工副产物的利用， 对椰子球蛋白进行限制性水解制备多肽，并采用Sephadex G-25凝胶柱层析对多肽进行纯化，然后以椰子球蛋白多肽为原料与亚铁离子反应制备肽-亚铁离子螯合物。重点分析水解度、温度等因素对椰子球蛋白多肽亚铁离子络合能力的影响，并优化制备工艺。结果表明，用碱性蛋白酶结合风味蛋白酶制备的多肽的水解度最高（14.71%），产物的亚铁离子螯合能力也最高（24.66%）;Sephadex G-25凝胶柱层析中分离出3个多肽组分，其中组分C的络合能力最高（28.67%）;椰子球蛋白多肽C螯合亚铁离子最佳条件是多肽浓度1 mg/mL、40 ℃、 pH 7.0、亚铁离子浓度0.5 mg/mL、时间0.5 h，此时螯合率为30.67%。荧光光谱、红外光谱等分析表明，椰子球蛋白多肽通过氨基、羧基和亚甲基与亚铁离子配位而形成螯合物。研究结果表明，用椰子球蛋白多肽为原料制备肽-亚铁螯合物切实可行，该螯合物可以应用于功能食品中来改善铁营养缺乏。

关键词：椰子球蛋白;多肽-亚铁螯合物;制备;Sephadex G-25凝胶色谱;优化

中图分类号：S667.4;TS255.4      文献标识码：A

Abstract： To improve the utilization of coconut processing byproduct， peptides were obtained from coconut globulin using limited enzymatic hydrolysis technology and purified by Sephadex G-25 chromatography in this study. Then the selected coconut globulin peptides were reacted with ferrous to prepare peptides-ferrous chelate. The effects of hydro-lysis degree， pH， time， ferrous ion concentration and temperature on the chelating ability of coconut globulin peptides were studied. Moreover， the chelating conditions were optimized using an orthogonal test. Results showed that both hydrolysis degree （14.71%） and ferrous chelating ratio （24.66%） were the highest when coconut globulin was hydro-lyzed by alcalase and flavourzyme. There were three peptides peaks through Sephadex G-25 chromatography， of which the fraction C showed the highest chelating ability （28.67%）. The result of the orthogonal test demonstrated that the optimum preparation conditions were peptide concentration 1.0 mg/mL， 40 ℃， 0.5 h， pH 7.0 and ferrous ion concentration 0.5 mg/mL， then the chelating ratio of coconut globulin peptides was 30.67%. The results of fluorescence spectroscopy and infrared spectroscopy indicated that coconut globulin peptide could chelate iron with amino groups， carboxyl groups and methylene groups. The results showed that it is feasible to prepare peptide-iron chelate using co-conut globulin. Moreover， the coconut globulin peptide-iron chelate could be used as functional food ingredient to im-prove iron deficiency status.

Keywords： coconut globulin; peptide-ferrous chelate; preparation; Sephadex G-25 chromatography; optimum

DOI： 10.3969/j.issn.1000-2561.2021.05.038

鐵是机体正常生命活动中必不可少的微量元素，当机体对铁的需求量增加，而机体本身铁的含量无法完全满足正常红细胞的生成，就使得血清中的铁浓度以及铁蛋白同时发生下降的情况，从表面可观察到皮肤系统以及黏膜没有血色等贫血表现[1]。缺铁性贫血是当前全人类面临的营养问题之一。由于食物中的铁主要以三价铁形式存在，在体内的吸收利用率低，因此改善缺铁性贫血的有效方法是摄入适量的补铁剂。……