美拉德反应中间体水相定向制备机制及其加工风味受控形成规律研究

Although Maillard reaction products are commonly used as savory flavoring ingredients, it is quite difficult to maintain their stability and desirable flavor quality during food processing because of their high volatility. However, Maillard reaction intermediates, especially Amadori rearrangement products (ARP) or Heyns rearrangement products (HRP) can be used as flavor precursors with relative stable physicochemical properties and low volatility. They are easily decomposed by subsequent heat treatment to produce different flavor substances. Various ARP and HRP will be prepared as flavor precursors by gradient temperature-elevating Maillard reaction. More attention will be taken on the study of controlled preparation of ARP and HRP at low-temperature aqueous phase with cysteine as tracer. The distribution of N-Glucosylamines (or N-Fructosylamines) and ARP (or HRP), and the regularity of transformation between them will be investigated. With the isotope labeling method, the dynamic mechanisms for controlling formation of intermediates will be analyzed. The coupling temperature-controlled reaction with low boiling dehydration technique will be studied as a new efficient method to improve the yield of target ARP and HRP. This approach will be demonstrated to avoid the defects of high pollution and high cost of traditional preparation by organic solvent. The regularity of thermal decomposition for ARP and HRP will be studied and Maillard reaction mechanism of them will be revealed. The controlled formation of process flavors from ARP and HRP and corresponding critical control point will then be evaluated to get fresh flavors, which will provide high cooking pleasure and sense of achievement for the consumers. The correlation between antioxidant activities of ARP or HRP and their composition will be studied, and the critical factors will then be illuminated by partial least squares regression. The research achievements will provide theoretical and technical supports for the sustainable development of savory flavoring industry.

咸味调味品常用配料完全美拉德反应产物在食品加工过程中难以维持稳定增香效果，而美拉德反应中间体（Amadori重排产物(ARP)和Heyns重排产物(HRP)）作为风味前体理化性质较稳定、挥发性低，后续热加工易产生风味物质。基于变温美拉德反应制备系列ARP和HRP类风味前体。重点研究半胱氨酸为示踪剂水相低温制备ARP和HRP方法，考察初级产物中N-糖胺、ARP或HRP分布、转化规律，借助同位素标记手段解析中间体形成动力学调控机制；明晰控温反应-低沸脱水定向高效制备目标产物的途径，克服传统有机溶剂法制备技术的高污染、高成本缺陷。研究ARP和HRP热解规律，揭示中间体美拉德反应历程，研究其加工风味受控形成规律及关键调控点，实现产生新鲜风味目的，也可为消费者带来烹饪的愉悦和成就感。研究ARP和HRP抗氧化能力，采用偏最小二乘回归法阐明其关键影响因素。研究成果将为我国风味工业可持续发展提供理论依据。

咸味调味品常用配料完全美拉德反应产物在食品加工过程中难以维持稳定增香效果，采用理化性质稳定的美拉德反应中间体可实现加工风味受控形成，研究其水相示踪制备机制、方法及热加工风味形成规律具有重要意义。.建立了半胱氨酸、谷胱甘肽和表没食子儿茶素没食子酸酯（EGCG）示踪制备美拉德中间体的机制，采用变温美拉德反应示踪法制备系列美拉德中间体。.在变温美拉德反应中，半胱氨酸能够将中间体2-木糖基噻唑烷-4-羧酸（TTCA）重新还原为底物，而谷胱甘肽和EGCG可与Amadori重排产物（ARP）或脱氧糖酮反应形成加合物，进而抑制褐变发生，据此示踪中间体形成的临界条件，在此条件下低温水相制备中间体，对其进行分离纯化与结构表征，进而对变温美拉德反应方法学进行了验证。.明确了中间体水相形成的关键动力学调控因素，提出控温反应-真空脱水耦联方法实现中间体高效制备。.通过解析水相美拉德反应过程中中间体分布及相互转化规律，发现脱水处理引起美拉德反应初级阶段化学平衡正向移动进而促进N-糖基胺向ARP定向转化，亚硫酸盐的pH缓冲效应能够进一步提高中间体产率。.阐明了中间体热解的美拉德反应历程及其加工风味受控形成规律，明晰了中间体形成新鲜风味的强度优势与速度优势；确定了中间体抗氧化能力。.ARP和Heyns重排产物（HRP）在热加工过程中能够快速发生降解，形成挥发性物质及类黑素，提高热加工温度和pH值可加速该过程。而完全美拉德反应产物在热加工过程中挥发性风味物质逐渐减少，风味轮廓发生改变。中间体热加工形成的风味浓度远远高于完全美拉德反应产物及糖-氨基酸混合物。外源糖对中间体热加工风味形成具有重要贡献。美拉德中间体具有一定的抗氧化能力，自由基电子可以使其形成分子内氢键，重排成为热力学稳定的自由基中间体而抑制氧化。.研究成果深化了美拉德反应理论认识，为美拉德中间体的规模化生产与应用提供重要的理论基础。