HPLC system with photodiode array (PDA) and evaporative light scattering (ELS)detectors

本申请要求购买一台高效液相色谱仪（HPLC），用于表征细菌对芥菜硫代葡萄糖苷的降解。芥末粉的工业除臭允许这种成分用作加工肉制品中的蛋白质补充剂，因为内源性植物酶，黑芥子酶，在热处理过程中被破坏，使粉末具有中性的风味和气味特征。粉末和改性产品中的硫代葡萄糖苷在颜色和风味方面保持不变。我们已经发现，许多食源性病原体，如产毒大肠杆菌、沙门氏菌、弯曲杆菌和单核增生李斯特菌，使用一种类似芥子酶的酶，在细胞内将芥子硫代葡萄糖苷转化为对生产生物体致命的异硫氰酸酯。因此，除臭芥菜可作为食品中的天然抗菌剂。初步研究表明，当葡萄糖易于获得时，靶菌的黑芥子酶合成和硫代葡萄糖苷利用受到抑制，因此下一步研究计划通过改变环境暴露和研究生长和静止细胞中酶合成的遗传控制来优化酶合成，以扩大这种独特的抗菌方法的应用范围。硫代葡萄糖苷异化的高效液相色谱分析是这项工作的基础，对于确定影响黑芥子酶合成和细菌降解硫代葡萄糖苷的因素至关重要。目前，用于这些分析的已有22年历史的HPLC容易出现频繁故障，并且需要昂贵的更换部件（操作软件只有部分功能，数据存储格式已经过时）。由于对使用这种设备的要求很高，使用通常远离新闻部的备用设备是一种不切实际的解决办法。由3名申请者（Holley， 4名学生；Arntfield， 2名学生，蛋白质-酚化合物相互作用对质地/风味功能的影响；Scanlon， 3名学生，气相对食物质地的影响）进行的9名HQP研究将能够使用该设备完成他们的工作。

This application requests the purchase of a high performance liquid chromatograph (HPLC) to be used in characterizing the degradation of mustard glucosinolates by bacteria. Industrial deodorization of mustard powder permits this ingredient to be used as a protein supplement in processed meat products because the endogenous plant enzyme, myrosinase, is destroyed during thermal treatment, giving the powder neutral flavour and odour characters. Glucosinolates in the powder and amended products remain unchanged in terms of colour and flavour. We have discovered that many foodborne pathogens such as toxigenic E. coli, Salmonella, Campylobacter, and Listeria monocytogenes use a myrosinase-like enzyme(s), and intracellularly transform the mustard glucosinolates into isothiocyanates which are lethal to the producing organism. Thus, deodorized mustard can be used as a natural antimicrobial in food. Initial studies indicated that when glucose was readily available, myrosinase synthesis and glucosinolate utilization were repressed in target bacteria, so further study is planned to optimize enzyme synthesis by altering environmental exposures and studying genetic control of enzyme synthesis in growing and resting cells to broaden application of this unique antimicrobial approach. HPLC analysis of glucosinolate dissimilation represents the cornerstone of this work and is essential to identify factors influencing myrosinase synthesis and glucosinolate degradation by bacteria. At present the 22 year-old HPLC used for these analyses is prone to frequent failures and requires expensive replacement parts when these are available (operational software is only partially functional and the data storage format is obsolete). The high demand placed on use of this equipment makes access to alternate equipment, often remote from the Department, an impractical solution. Studies by 9 HQP working on NSERC Discovery-funded research conducted by the 3 applicants (Holley, 4 students; Arntfield, 2 students, protein-phenolic compound interactions on texture/flavour functionality; Scanlon, 3 students, gas phase effects on food texture) will be able to complete their work with this equipment.