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），用于表征细菌对芥子油苷的降解。芥末粉的工业发酵允许这种成分在加工肉制品中用作蛋白质补充剂，因为内源性植物酶黑芥子酶在热处理过程中被破坏，使粉末具有中性风味和气味特征。粉末和改良产品中的硫代葡萄糖苷在颜色和风味方面保持不变。我们发现许多食源性致病菌，如大肠杆菌。大肠杆菌、沙门氏菌、弯曲杆菌和单核细胞增生李斯特菌使用黑芥子酶样酶，并在细胞内将芥子油苷转化为对生产生物体致命的异硫氰酸酯。因此，芥末可以作为食品中的天然抗菌剂。最初的研究表明，当葡萄糖是容易获得的，黑芥子酶的合成和芥子油苷的利用被抑制在目标细菌，因此，进一步的研究计划，以优化酶的合成，通过改变环境的暴露和研究在生长和静止细胞中的酶合成的遗传控制，以扩大这种独特的抗菌方法的应用。高效液相色谱法分析硫代葡萄糖苷异化是这项工作的基石，是必不可少的，以确定影响黑芥子酶合成和细菌降解硫代葡萄糖苷的因素。目前，用于这些分析的22年历史的HPLC容易频繁发生故障，并且在可用时需要昂贵的更换部件（操作软件仅部分功能，数据存储格式过时）。由于对使用这些设备的需求很大，因此使用往往远离该部的替代设备是一个不切实际的解决办法。由3名申请人（霍利，4名学生; Arntfield，2名学生，蛋白质-酚类化合物对质地/风味功能的相互作用; Scanlon，3名学生，气相对食品质地的影响）进行的NSERC Discovery资助的9项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parts when these are available (operational software is only partially functional and the data storage format is obsolete).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.