摘要
为开发安全高效且易吸收的补锌剂,利用碱性蛋白酶酶解和乳酸菌发酵相结合的方法制备生物活性肽,并以此多肽制备了酪蛋白肽锌螯合物。采用光谱法对螯合物结构进行表征,利用体外消化模型和Caco-2细胞实验对其胃肠消化特性及生物安全性进行评价。结果表明,制备酪蛋白肽的最优条件为酶解pH为9、碱性蛋白酶添加量为0.3%(w/v),乳酸菌发酵时间为12 h,此时反应体系中多肽含量为142.39±0.95 mg/g,对锌的螯合率为31.41%±0.97%。与锌螯合后,酪蛋白肽表面的致密结构遭到破坏,形成疏松的状态;光谱学分析表明,Zn^(2+)能与酪蛋白肽上的活性基团进行结合,螯合位点为羧基氧、羟基氧和氨基。体外模拟消化结果显示,酪蛋白肽锌螯合物在消化过程中锌溶解性优于硫酸锌;在胃肠消化后酪蛋白肽锌螯合物DPPH和ABTS+自由基的清除能力分别提升了26.19%±3.30%和71.96%±7.06%,而铁还原力下降了36.26%±2.80%;同时,在消化过程中肽锌螯合物的β-转角与无规则卷曲含量减少,β-折叠结构增加,Zn^(2+)起到了维持多肽结构的作用。细胞实验表明,当浓度大于0.4 mg/mL时,肽锌螯合物胃肠道消化物对Caco-2细胞表现出一定的细胞毒性。最后,利用质谱技术分别从酪蛋白水解物和肽锌螯合物中鉴定出15条和13条乳源多肽。研究结果可以为高效安全的酪蛋白肽锌补充剂的制备和应用提供科学依据。
In this study,casein peptides were obtained by alcalase hydrolyzation and Lactobacilus fermentation to prepare the casein peptide-zinc chelates,which are a kind of efficient and well-absorbed zinc supplement.The structure of casein peptide-zinc chelates was characterized by spectroscopic instruments.The digestive stability and safety were also assayed using in vitro digestive model and Caco-2 cell experiment.The results indicated that the optimal conditions for preparing casein peptides were as follows:Volume of alcalase was 0.3%(w/v),pH of reaction system was 9.0,Lactobacilus fermentation time was 12 h.Under this condition,the peptide content was 142.39±0.95 mg/g,and the zinc chelation rate was 31.41%±0.97%.The chelation with zinc destroyed the structure of casein peptides leading to a loose surface structure.Spectroscopic analysis showed that Zn^(2+)can bind to the reactive groups on casein peptides,with the chelating sites being carboxyl oxygen,hydroxyl oxygen and amino groups.The results of in vitro digestion showed that casein peptide-zinc chelates possessed better solubility than that of zinc sulfate.After gastrointestinal digestion,the DPPH and ABTS+scavenging ability of casein peptide-zinc chelates increased by 26.19%±3.30%and 71.96%±7.06%,respectively.However,the ferric ion reducing power of the casein peptide-zinc chelates decreased by 36.26%±2.80%.At the same time,theβ-turn and random coil content of the casein peptide-zinc chelate decreases during digestion,theβ-sheet structure increases and Zn^(2+)play a role in maintaining the peptide structure.Furthermore,the cytotoxicity test indicated that casein peptide-zinc chelates gastrointestinal digest were toxic to Caco-2 cells when the concentration exceeded 0.4 mg/mL.Finally,15 and 13 dairy-derived peptides were identified from casein hydrolysate and casein peptide-zinc chelates,respectively,using mass spectrometry.These results will provide scientific evidence for the development and application of efficient casein peptide-zinc chelates.
作者
周桂成
肖珊
王波
王际辉
ZHOU Guicheng;XIAO Shan;WANG Bo;WANG Jihui(School of Biological Engineering,Dalian Polytechnic University,Dalian 116034,China;School of Life and Health Technology,Dongguan University of Technology,Dongguan 523808,China)
出处
《食品工业科技》
CAS
北大核心
2023年第23期270-279,共10页
Science and Technology of Food Industry
基金
广东省基础与应用基础研究基金(2020A1515110211)
广东省普通高校特色创新项目(2021KTSCX132)
东莞理工学院高层次人才(创新团队)科研启动项目(KCYCXPT2017007)
广东省创新强校创新团队项目(2021KCXTD035)。
关键词
酪蛋白肽
肽锌螯合物
发酵优化
体外消化
生物利用率
casein peptide
peptide-zinc chelate
fermentation optimization
in vitro digestion
bioavailability
