食用前处理方式对凉拌湿米粉灭菌效果的调查

目的调查南昌市早餐凉拌湿米粉食用前处理方式对卫生状况的影响。方法随机抽取南昌市各县区早餐湿米粉40个样品120份,每个样品分别作未加热,加热烫15s,加热烫30s处理。采用无菌送检,检测菌落总数、大肠菌群、金黄色葡萄球菌、志贺菌、沙门菌。结果菌落总数、大肠菌群加热烫15s,加热烫30s和未加热时存在显著差异(P<0.05),120份样品全部未检出金黄色葡萄球菌、志贺菌、沙门菌等致病菌。结论说明加热对杀灭微生物有显著效果,且加热时间越长灭菌效果越好,灭菌效果同加热时间成正相关,与微生物的耐热程度呈负相关,早点拌粉的食用方式为加热烫30s后凉拌食用更安全^([1])。

食前热水处理提高鲜切黄瓜微生物安全性的研究

探讨食前热水处理能否有效杀灭鲜切黄瓜表面的单增李斯特菌和鼠伤寒沙门氏菌这两种食源性致病菌,同时又保持其新鲜度。实验首先根据热水处理后鲜切黄瓜的感官品质,筛选了其耐热条件,进一步研究了热处理对水中和鲜切黄瓜表面食源性致病菌降低的效果。结果表明,经60℃ 5min热水处理,鲜切黄瓜上的鼠伤寒沙门氏菌、单增李斯特菌数量从高起始染菌浓度5.42、5.16log CFU/g,降低到检测线(0.6log CFU/g)以下,鲜切黄瓜的抗氧化值降低、细胞膜透性有所提高,但其测定硬度变化不大,感官上仍鲜脆,仍具有较好食用价值。

影响蔬菜中亚硝酸盐含量的因素研究

试验研究了蔬菜在不同储存时间与储存温度、不同食用前处理和不同加工方法等条件下亚硝酸盐含量的变化,结果表明,蔬菜中亚硝酸盐的含量随储存时间的延长会逐渐升高,达到最大值后有所下降。不同蔬菜中亚硝酸盐的含量随温度的变化而不同。漂烫处理可以降低蔬菜中亚硝酸盐的含量,浸泡处理会使亚硝酸盐含量升高。蔬菜经炒熟或煮熟后亚硝酸盐含量均会降低,并且煮熟的蔬菜亚硝酸盐含量低于炒熟的蔬菜。

The Possibilities of Bioenergy Production from Whey

The wastes and the by-products of food industrial technologies are suitable for bioenergy generating because of the high organic matter content. Anaerobic digestion is the eldest technology for waste stabilization and however by controlled decomposition a high value and marketable energy source can be produced. Whey is normally used as a component of dairy products or as an additive for food product. In our work we focused on another utilization method： biogas generating from membrane separated fractions i.e.： permeate and concentrate of whey. The effect of the pH, thermal, microwave pre-treatment and their combinations on the biogas yield were investigated. Our results showed that the applied pre-treatments had significant effect on biogas production. In consequence of the hydrolysis of large molecules the biodegradability of the pre-treated whey fractions was enhanced, therefore the biogas and methane production yield increased significantly.