不同初加工方式下莴笋亚硝酸盐含量变化研究

摘要

In order to reveal the reason of producing nitrite of Lactuca sativa L .var .in storage ,Asparagus let‐tuce were pretreated by stay the original state ,granular ,powdery and stored in 1 ,4 and 8℃ .The nitrite content was detected and the change pattern of total plate count was analyzed in asparagus lettuce .The results indicated that the nitrite was detected initially and the maximum accumulation was obtained in 8℃ .The nitrite content and total number of colonies had dynamic relationship .The microbial growth ,nitrite content and the earliest de‐tection time of nitrite in asparagus lettuce which pretreated by different primary processing were all appeared to stay the original state< granular< powdery .Almost six strains had the characteristic of nitrate reduction ,ac‐counted for 6/10 of total colony .Reproduction of nitrate reducing bacteria caused nitrite accumulation in aspar‐agus lettuce .%为揭示莴笋贮藏过程中亚硝酸盐产生的本质原因，对莴笋进行保持原状、颗粒状、粉末状处理，并置于1、4和8℃条件下贮藏，分析莴笋中亚硝酸盐含量和菌落数的变化规律及二者的动态关系。结果表明：粉末状处理在8℃下贮藏时，莴笋最早检出亚硝酸盐，且亚硝酸盐积累量最大。莴笋中菌落总数变化与亚硝酸含量变化存在动态关系，3种初加工方式莴笋中微生物的生长速度快慢和亚硝酸盐含量高低及最早检出时间都表现为保持原状＜颗粒状＜粉末状。分离得到的6株细菌具有硝酸盐还原特性，为挑取总菌落数的6／10，初步推断硝酸盐还原菌的大量繁殖导致了莴笋中亚硝酸盐的积聚。