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

豆类等植物性食物富含蛋白质，也是重要的经济作物。然而，豆类中的异味或芳香活性化合物和抗营养化合物的存在可能会降低蛋白质和必需矿物质的吸收，是食品加工的主要挑战。虽然已经研究了豆类的功能属性，但对它们与异味化合物的蛋白质相互作用知之甚少。脂类修饰酶和储存条件是导致异味形成的已知因素，但它们在新斯科舍省豆类品种中的作用尚未确定。此外，尽管蛋白质本身没有味道，但它们可以与异味化合物相互作用，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得到探索。与动物来源的蛋白质相比，豆类的消化率较低，这可能是由于存在抗营养因子。然而，目前还不知道蛋白质的动力学稳定性在这些食物系统的消化率中起到了什么作用。因此，假设：脂质修饰酶和蛋白质相互作用在改变NS豆和鹰嘴豆的风味方面起着重要作用；蛋白质在这些食品体系中的动力学稳定性可能会影响它们的消化率。这项研究计划的长期目标是更好地了解植物性食品风味形成的机制，以及脂肪修饰酶、蛋白质相互作用和蛋白质动力学稳定性对这些食品系统的风味特征和营养质量的发展的贡献。将使用气相色谱-嗅觉/质谱仪方法来鉴定在NS豆类和鹰嘴豆的传统前处理后产生的特征香气活性化合物。还将评估脂质修饰酶和储存条件对修改这些风味特征的影响。将通过改变蛋白质基质的pH和温度以及使用不同的键破坏剂来评估驱动芳香活性化合物保留或释放的关键分子变化。蛋白质组学方法也将被用来确定感兴趣样品中动力学稳定的蛋白质的丰度和特性。这项拟议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特征修改的贡献的理解。了解驱动这些相互作用的机制将有助于预测香料释放曲线，并帮助产品开发人员应对香料交付挑战。此外，新发现的动力稳定蛋白质可以加强正在进行的提高豆类作物可持续性的努力，这将是一种有效的长期战略，这将有利于提高这些食品系统的经济价值。

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.