采用高通量组分析法研究蓝莓馅料在焙烤过程中的多酚变化与内源性污染物的形成规律

Blueberry is of high nutritional value, and contains high amounts of sugars, organic acids, vitamin C and polyphenols as well as small amounts of fats, proteins and amino acids. Berry processing industry has been developed rapidly in China. As a result, blueberry was widely introduced into fillings of various bakery produces in recent years. However, the thermal condition and low pH value of the berry fillings might cause the degradation of heat-sensitive compounds, such as polyphenols, during baking. High temperature and low pH may also provide favorable environment for the formation of endogenous contaminants, such as furfuran and 5-hydroxymethylfurfural (HMF), by various reactions of/between reducing sugars, proteins, and vitamin C, etc. Nevertheless, little is known about the complicated interactions between these components in blueberry fillings during baking. The current study focuses on the changes of polyphenols and the formation of furfuran and HMF in blueberry fillings during baking. To achieve the aim, high-throughput analysis with Nuclear Magnetic Resonance (NMR), in combination with High Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS/MS) will be applied on different baking samples. The results will be analysed qualitatively and quantitatively via statistical analyses to reveal the changes and their mechanisms of polyphenols in blueberry fillings during baking, and their response to the variation of baking conditions. The mechanisms of the formation of furfuran and HMF in blueberry fillings during baking in relation to the baking conditions will also be investigated. The present study reveals the influence of thermal processing on the compositional changes of polyphenols and the potential risks in food safety. The results provide useful guidelines, in aspects of nutritional value and food safety, for the feasibility of the application of blueberry in the baking fillings.

蓝莓营养价值高，富含糖、有机酸、维生素C、多酚和少量脂肪、蛋白质、氨基酸。蓝莓生产和加工在我国发展迅速，近年来被广泛用作各种焙烤食品馅料。蓝莓馅料的酸性环境和高温加工可能使多酚等热敏物质发生降解，并导致还原糖、蛋白质、维生素C等发生化学反应产生呋喃和羟甲基糠醛等有害物质。但目前对蓝莓馅料在焙烤过程中的组分互作缺乏深入研究。本项目拟采用核磁共振高通量组分析技术，结合液质联用等，研究蓝莓馅料在焙烤过程中的多酚组分变化机制和内源污染物的形成规律。具体内容为：（1）获得不同样品的核磁共振氢谱和质谱数据，通过数据分析，定性、定量地研究蓝莓馅料在不同焙烤条件下的多酚组分变化机制。（2）研究蓝莓馅料在焙烤过程中呋喃和羟甲基糠醛的形成规律。本研究将揭示高温焙烤对蓝莓多酚组分的影响机制及其可能产生的安全风险，从营养和安全角度，为蓝莓作为焙烤馅料的可靠性提供科学依据。

本项目针对蓝莓酥在加工过程中的营养成分，特别是多酚类物质的变化规律以及内源性有害物呋喃和羟甲基糠醛的形成规律进行研究，获得以下成果：（1）采用HPLC-MS/MS对蓝莓酥馅料进行全组分分析，共鉴定出630种成分，筛查出馅料热加工过程中含量变化显著的差异成分288种，发现其中多酚类物质热降解最严重；（2）多酚物质的降解主要发生于馅料炒制阶段，焙烤对其成分影响不大；（3）花色苷对热加工的敏感度大于黄酮醇类物质，花色苷的结构不同也影响其热降解，飞燕草素糖苷最不稳定，其次为锦葵色素糖苷、矮牵牛花素糖苷、矢车菊素糖苷；（4）蓝莓馅料中未检出热加工有害物呋喃，但在炒制过程中产生大量HMF，市售蓝莓酥中HMF的含量高达3231 mg/kg，是曲奇的40多倍；（5）分析蓝莓馅料配方和工艺对HMF形成的影响，提出炒制过程是控制HMF生成的关键工序，己糖热降解是HMF形成的主要途径，Maillard反应也参与HMF的形成，还原糖含量和馅料pH值是影响HMF形成的主要因素，花色苷对馅料中5-HMF的形成也有促进作用，且主要通过已糖热降解途径；（7）发表论文7篇（SCI论文6篇，中科院1区4篇，中文核心1篇），参编专著1部。 . 本项目的科学意义及社会贡献在于：通过系统分析蓝莓酥馅料中多酚类物质的降解规律及内源性有害物HMF的形成机制和规律，为水果酥类热加工食品的品质改良与安全控制提供借鉴与参考。本研究结果也对蓝莓酥类食品的食用安全性提出警示：市售蓝莓酥中HMF含量普遍较高，最高达3231 mg/kg，依据欧洲食品安全局（EFSA）的推荐阈值0.54 mg/day计，食用一块蓝莓酥HMF摄入量即超过安全限定值的150倍，可能造成健康风险，因此对于其有害物的形成和控制应引起重视，有必要进行深入的机理和控制研究。.