超高压处理对哈密瓜汁品质酶和微生物的影响

本文对不同超高压处理后的哈密瓜汁中的POD、PPO和LOX的活性进行了测定，同时对哈密瓜汁中微生物及其对象芽孢菌和安全性评价菌E．coli的耐压性进行了实验。研究结果表明：哈密瓜汁经500MPa、20min处理后，其POD、PPO和LOX的残留活力分别为81％、8．06％和6．84％，在同等处理条件下，对象芽孢菌耐压，大肠杆菌不耐压且降低了5个对数级，符合美国FDA鲜榨果蔬汁非热力杀菌的安全要求，哈密瓜汁中的细菌总数≤100CFU／ml，符合我国饮料的卫生标准。

Effect of Ultra High Pressure Treatment on Quality-related Enzymes and Bacterium of Hami Melon (Cucumis Melo L.)Juice

The paper systematically studied the residual activities of POD, PPO and LOX enzymes in Hami melon juice pressurized at 500MPa for 3-20min, and its bacteria total count, target spore bacteria and E.coli as safety index bacteria were also treated at the same condition. The results showed that at 500MPa for 20min treatment, the pressure tolerance of POD was greater than that of PPO and LOX, their residual activities were 81%, 8.06% and 6.84% respectively, the spores were pressureresistant, E.coli was sensitive to ultra high pressure and the pressurized melon juice reached the safety standards of FDA on fruit and vegetable juice nonthermal processing and the domestic beverage standards.