基于配位作用的铁-大豆蛋白纳米复合物制备及性质  

Preparation and Properties of Iron-Soy Protein Nanocomplexes Based on Coordination

作　　者：詹宏栋 刁聪聪 赵谋明[1] 周非白[1] ZHAN Hongdong;DIAO Congcong;ZHAO Mouming;ZHOU Feibai(School of Food Science and Engineering,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]华南理工大学食品科学与工程学院,广东广州510640

出　　处：《食品科学》2023年第8期1-8,共8页Food Science

基　　金：国家自然科学基金面上项目(32172157)。

摘　　要：为拓宽铁强化剂在食品工业生产中的应用,本研究以大豆分离蛋白(soy protein isolate,SPI)为原料对其进行碱热预处理(pH 12,85℃,30 min)后,与FeSO_(4)反应制备纳米复合物。结果表明,预热处理后大豆分离蛋白(alkali-heat-treated soybean protein isolate,HSPI)可与适当浓度的FeSO_(4)反应形成稳定分散的纳米复合物(Fe-HSPI),该过程受反应pH值影响。随着反应pH值的升高,Fe-HSPI的尺度改变,颜色逐渐加深;不同pH值下制备的Fe-HSPI均具有较好的消化稳定性,经模拟胃肠消化后仍保持蛋白与Fe^(2+)的结合,有利于避免游离铁对胃肠道的刺激。其中,pH 7下制备的纳米复合物(Fe-HSPI_(pH 7))均一性较好(多分散系数<0.2),且消化后的可溶性铁含量超过80%,具有良好的吸收利用潜力。Fe-HSPI_(pH 7)中,Fe^(2+)与HSPI的结合会引起HSPI肽链折叠并形成二硫键维持稳定的结构,主要结合位点为氨基的氮原子和羧基的氧原子。与FeSO_(4)相比,Fe-HSPI_(pH 7)在水包油乳液中引起的脂质氧化程度显著降低,表现出更低的反应活性,作为铁营养强化剂具有更好的应用潜力。In the present study,in order to broaden the application of iron fortifiers in the food industry,alkali-heat treated soybean protein isolate(HSPI)was reacted with FeSO_(4)to fabricate stable iron-containing nanocomplexes.The results showed that the reaction of HSPI with an appropriate concentration of FeSO_(4),which was pH dependent,could form stably dispersed nanocomplexes(Fe-HSPI).The size of Fe-HSPI changed with increasing reaction pH,and the color became darker.Fe-HSPI was stable against in vitro digestion,and the binding between protein and Fe^(2+)was maintained during simulated gastrointestinal digestion,which could be beneficial to prevent free iron stimulating the gastrointestinal tract.Herein,Fe-HSPI prepared at pH 7(Fe-HSPI_(pH 7))had good homogeneity(polydispersity index,PDI<0.2)and the content of soluble iron after digestion was more than 80%,showing a remarkable potential for absorption and utilization.The Fe^(2+)in Fe-HSPI_(pH 7)mainly combined with the nitrogen atom of the amino group and the oxygen atom of the carboxyl group in HSPI,thereby facilitating the folding of the peptide chain and resulting in the formation of a structure stabilized by disulfide bonds.Compared with FeSO_(4),Fe-HSPI_(pH 7)induced a significantly lower degree of lipid oxidation when applied in oil-in-water emulsions,thus exhibiting lower reactivity and having better potential for application as an iron fortifier.

关 键 词：大豆分离蛋白 硫酸亚铁 纳米复合物 脂质氧化 

分 类 号：TS201.2[轻工技术与工程—食品科学]