Differential scanning calorimeter for evaluation of food structures

检查食品系统结构的方法之一是测量改变这些结构所涉及的热量。这种热需求可能是由于相变，如冰的融化，但对于碳水化合物来说，糊化淀粉颗粒需要热，而对于蛋白质来说，展开或变性的过程需要热。差示扫描量热计(DSC)能够测量食物样品在特定温度范围内加热时吸收或释放的热量。如果在分析之前材料的结构发生了变化，这将反映在吸收的热量和发生这种转变的温度上。因此，这是监测特定修饰或加工操作导致的蛋白质结构变化的有效工具。在较小的酶蛋白上工作良好的工具很难用于食品蛋白，因为它们的尺寸和/或溶解性。因此，该设备将支持旨在改善植物蛋白凝胶特性的研究项目，使用处理方法，如在凝胶形成之前对蛋白质进行酶促修饰，以及表征复杂小麦面团系统中的单个聚合物。当调制的DSC检测温度线性升高和振荡或正弦温度升高的响应时，这提供了能够研究复杂系统中的单个蛋白质并提高测量灵敏度的优势。这些信息将帮助我们更好地理解植物蛋白的酶修饰改善凝胶特性的机制，并帮助我们表征面团中蛋白质的行为。

One of the ways to examine structures in food systems is to measure the heat involved in changing these structures. This heat requirement could due to a phase change, such as the melting of ice, but for carbohydrates heat is required to gelatinize the starch granules, while for protein the process of unfolding or denaturing requires heat. A differential scanning calorimeter (DSC) has the ability to measure the heat taken in or given off as a food sample is heated over a specified temperature range. If changes occur in the structure of the material prior to analysis, this will reflected in the amount of heat that is taken in and the temperature at which this transition occurs. As a result, this is an effective tool for monitoring changes in protein structure as a result of specific modifications or processing operations. Tools that work well on smaller enzymatic proteins are difficult to use with food proteins due to their size and/or solubility.  This equipment will therefore support research programs looking at improving the gelation properties of plant proteins, using treatments such as enzymatic modification of the protein prior to gel formation, as well as characterizing individual polymers in the complex wheat dough system. As the modulated DSC examines the response to both a linear increase in temperature and an oscillating or sinusoidal temperature increase, this provides the advantage of being able to investigate individual proteins in a complex system and improve the sensitivity of the measurements. This information will help us improve our understanding of the mechanisms whereby enzymatic modification of plant protein improves gelation properties and help us characterize the behaviour of proteins in dough.