食品科学2025，Vol.46Issue(22)：92-100,9.DOI:10.7506/spkx1002-6630-20250427-219
温压协同微环境对柑橘果胶甲酯酶与抑制剂的影响机制
Mechanism for the Effect of High Pressure Processing at Different Temperatures Combined with Microenvironment on Citrus Pectin Methylesterase and Its Inhibitor
摘要
Abstract
To address the problem that residual pectin methylesterase(PME)can cause turbidity loss and increased microbial safety risks in orange juice during high pressure processing(HPP),this study focused on the regulatory mechanism of HPP at different temperatures combined with microenvironment on PME and pectin methylesterase inhibitor(PMEI).Recombinant PMEI was prepared via molecular cloning,and circular dichroism(CD)spectroscopy,fluorescence spectroscopy,and molecular dynamics simulation were combined to systematically analyze the effects of multi-factor interactions on the enzyme activity and structure.The results showed that Ca2+concentrations in the range of 0.1-0.5 mol/L could completely inhibit PME activity under HPP/25℃treatment,while pectin concentration(0.1%-0.5%)had no significant regulatory effect on PME activity,but high pectin concentrations could cause physical interference.Under HPP/60℃treatment at pH 7.0,PME activity was decreased by more than 95%,accompanied by changes in its secondary structure and a significant alteration in the polarity of the tryptophan microenvironment.At pH 7.0,the secondary structure of PMEI heterologously expressed in Escherichia coli(E.PMEI)transformed from α-helix to β-sheet,with its inhibitory activity remaining stable.In contrast,the relative content of α-helix structure in PMEI heterologously expressed in Pichia pastoris(P.PMEI)and its inhibitory activity increased under acidic conditions.At the molecular level,these findings clarified that HPP combined with pH adjustment could dynamically regulate the activities of PME and its inhibitor by specifically altering their conformations,providing a theoretical basis for the development of new food processing technologies that allow precise control of pectinase activity.关键词
温压协同处理/果胶甲酯酶/贮藏微环境/pH值调控/构效关系Key words
high-pressure treatment at different temperatures/pectin methylesterase/storage microenvironment/pH regulation/structure-activity relationship分类
轻工业引用本文复制引用
刘祝银,李彦潼,江永利,易俊洁..温压协同微环境对柑橘果胶甲酯酶与抑制剂的影响机制[J].食品科学,2025,46(22):92-100,9.基金项目
国家自然科学基金青年科学基金项目(31901711) （31901711）
云南省应用基础研究计划项目(2019FD051) （2019FD051）
云南省科技重大专项(202102AE090050) （202102AE090050）
