Flavour Profiles and Nutrient Quality: Determining the roles of lipid modifying enzymes, protein-aroma active compound interactions, and protein stability in plant-based food systems

豆类等植物性食物是蛋白质的丰富来源，也是经济上重要的作物。然而，豆类中存在的变质或芳香活性化合物和抗营养化合物可能会降低蛋白质和必需矿物质的吸收，这是食品加工的一个主要挑战。虽然已经研究了豆类的功能属性，但对它们与非风味化合物的蛋白质相互作用知之甚少。脂质修饰酶和储存条件是已知的不良风味发展的贡献者，但它们的作用尚未确定在新斯科舍省豆类品种。此外，尽管蛋白质本身没有风味，但它们可以与非风味化合物相互作用并改变风味特征。对于新斯科舍省的豆类品种和鹰嘴豆来说，这些相互作用在很大程度上仍未被探索。与动物来源的蛋白质相比，豆类的消化率较低，这可能归因于抗营养因子的存在。然而，目前尚不清楚蛋白质的动力学稳定性在这些食物系统的消化率中起什么作用。因此，我们假设：脂质修饰酶和蛋白质相互作用在NS豆和鹰嘴豆的风味特征的修饰中起重要作用；而且，这些食物系统中蛋白质的动力学稳定性有可能影响它们的消化率。本研究计划的长期目标是更好地了解植物性食品风味发展的机制，以及脂质修饰酶、蛋白质相互作用和蛋白质动力学稳定性对这些食品系统风味特征和营养质量发展的贡献。将采用气相色谱-嗅觉-质谱联用技术对NS豆和鹰嘴豆进行传统预处理后产生的特征芳香活性化合物进行鉴定。还将评估脂质修饰酶和储存条件对这些风味特征的影响。驱动芳香活性化合物保留或释放的关键分子变化将通过改变蛋白质基质的pH值和温度以及使用不同的键破坏剂来评估。蛋白质组学方法还将用于确定感兴趣样品中动力学稳定蛋白的丰度和特性。提出的研究将提供新的发现，并提高我们对蛋白质相互作用及其对风味谱修改的贡献的理解。了解驱动这些相互作用的机制将使风味释放曲线的预测成为可能，并帮助产品开发人员应对风味传递的挑战。此外，新发现的动态稳定的蛋白质可以加强正在进行的努力，以提高脉冲作物的可持续性，这将是一个有效的长期战略，这将有利于提高这些粮食系统的经济价值。

Plant-based foods such as pulses are rich sources of protein and are also economically important crops. However, the presence of off-flavour or aroma-active compounds and anti-nutritional compounds in pulses may lower the absorption of proteins and essential minerals and is a major food processing challenge. Although the functional attributes of pulses have been studied little is known of their protein interactions with off-flavour compounds. Lipid-modifying enzymes and storage conditions are known contributors of off-flavour development, but their roles have not been defined in Nova Scotia bean varieties. Furthermore, although proteins have no flavour of their own they can interact with off-flavour compounds and modify flavour profiles. For Nova Scotia bean varieties and chickpeas these interactions remain largely unexplored. Compared to animal sources of proteins, pulses have lower digestibility which may be attributed to the presence of anti-nutritional factors. However, it is not known what role the kinetic stability of proteins plays in the digestibility of these food systems. Thus, it is hypothesized that: lipid modifying enzymes and protein interactions play a significant role in the modification of flavour profiles of NS beans and chickpeas; and, the kinetic stability of proteins in these food systems has the potential to impact their digestibility. The long-term objective of this research program is to better understand the mechanisms underlying flavour development in plant-based foods and the contribution of, lipid modifying enzymes, protein interactions and protein kinetic stability to the development of flavour profiles and the nutrient quality of these food systems. A gas chromatography olfactory/ mass spectrometry approach will be used to identify the characteristic aroma-active compounds generated after traditional pre-treatments of NS beans and chickpeas. The impact of lipid-modifying enzymes and storage conditions on modifying these flavour profiles will also be evaluated. The key molecular changes that drive the retention or release of aroma-active compounds will be evaluated by modifying the pH and temperature of protein matrices and using different bond-disrupting agents. A proteomics approach will also be used to determine the abundance and identity of kinetically stable proteins in the samples of interest. The proposed research will provide novel discoveries and improve our understanding concerning protein interactions and their contributions to the modification of flavour profiles. Understanding the mechanisms that drive these interactions will enable prediction of flavour release profiles and help product developers meet flavour-delivery challenges. Moreover, newly discovered kinetically stable proteins could enhance ongoing efforts to improve the sustainability of pulse crops which will be an effective long-term strategy which that will be beneficial in improving the economic value of these food systems.