Structure-related degradation of pectins and their impact on non-enzymatic browning and technological functionality

果胶的结构相关降解及其对非酶褐变和技术功能的影响

基本信息

批准号：
268547215
负责人：
Professor Dr. Stephan Drusch
金额：
--
依托单位：
Institut für Chemie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2017-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/268547215?language=en
关键词：
Structure related degradation pectins their

项目摘要

Processing and storage of food lead to chemical and biochemical changes in the biopolymeric constituents. Consequently, their functional properties modified by non-enzymatic browning reactions and oxidative processes. In contrast to reducing sugars, uronic acids as precursors in the Maillardreaction have rarely been studied. Hence, reaction processes, intermediates and reaction products of pectin degradation and their role in non-enzymatic browning reactions should be investigated. In model systems first results show a faster color development of uronic acids in comparison with reducing sugars. However, the hydrolytic and beta-eliminative cleavage does not provide a sufficient explanation. Additionally, the intermediates of the thermal induced degradation of pectins like saturated and 4,5-unsaturated oligogalacturonic acids are not systematically characterized. Regarding to the functional properties of modified pectins, further studies should be of interest. Objective of the project is to investigate and clarify the reaction mechanism of the thermally induced degradation of pectin. More precisely, the influence of the structure of starting materials and conditions used on intermediates formed and their role in color formation by the non-enzymatic browning (Maillard-reaction) should be elucidated. For this reason, different model systems will be used with galacturonic acid and its methyl ester, respectively. The purified partially methyl esterified saturated and unsaturated oligogalacturonic acids should be used separately in further models. Furthermore, the results should provide an insight into the mechanism of pectin degradation and the resultant effect to the physico-chemical characteristics of degradation products. The previously executed differential scanning calorimetry shows anomalies and a mechanism of degradation is postulated. The comparison of chemical investigations and structure-analytical characterizations as a part of the project could confirm our postulated degradation mechanism. Finally, the influence of degradation on functional properties of pectin should be examined. For this reason structures identified by NMR spectroscopy should be compared with results obtained during investigation of physico-chemical properties.

食物的加工和存储导致生物聚合成分的化学和生化变化。因此，它们的功能特性通过非酶褐变反应和氧化过程所改变。与还原糖相反，很少研究尿酸作为MaillardReaction中的前体。因此，应研究果胶降解的反应过程，中间体和反应产物及其在非酶褐变反应中的作用。在模型系统中，首先结果表明，与减少糖相比，尿酸的颜色发育更快。然而，水解和β-β-阐明裂解不能提供足够的解释。此外，果胶（如饱和和4,5含寡素的寡核酸）的热诱导降解的中间体没有系统地表征。关于改性果胶的功能性能，应进一步研究。该项目的目的是研究和阐明果胶热诱导降解的反应机理。更确切地说，应阐明使用非酶褐变（Maillard-Reaction）在颜色形成中的起始材料和条件结构对形成中间体的影响。因此，不同的模型系统将分别与半乳核酸及其甲基酯一起使用。纯化的部分甲基酯化的饱和和不饱和寡核酸应在其他模型中分别使用。此外，结果应提供对果胶降解机理以及对降解产物物理化学特征的结果作用的见解。先前执行的差分扫描量热法显示异常，并假定了降解机制。化学研究和结构分析表征作为项目一部分的比较可以证实我们假定的降解机制。最后，应检查降解对果胶功能特性的影响。因此，应将通过NMR光谱鉴定的结构与研究期间在物理化学特性研究中获得的结果进行比较。