生鲜面条保鲜方式及其菌群生长分析

ANALYSIS OF PRESERVATION AND FLORA GROWTH IN FRESH NOODLE

为探究紫外和微波方式对生鲜面条保鲜及其微生物的抑制效果,对9种不同尺寸的面条以紫外和微波两种方式进行保鲜处理,4℃贮藏3 d后,以营养琼脂培养基、马铃薯-葡萄糖-琼脂培养基检测生鲜面中的细菌、霉菌/酵母菌的数量,并对生长的菌落进行形态分析。结果表明:在贮藏过程中,熟制的9#面条(宽1.54 mm、厚1.15 mm)易滋生微生物;不同尺寸的生鲜面条对菌落生长有影响,以3#面条(宽2.01 mm、厚1.73 mm)的菌落数最高(P<0.01),细菌菌落达到108个/g以上,霉菌/酵母菌菌落不可计数;试验培养的细菌菌落主要有4种形态,培养的霉菌/酵母菌由多量分泌黏液的菌落和4种形态可辨的菌落组成。紫外处理的细菌总数(7.70×108)是微波处理的细菌总数(5.54×108)的1.38倍,微波保鲜对微生物的抑制效果优于紫外保鲜。细菌总数高于霉菌总数3.34倍(7.70/2.30×108),试验中生鲜面条的变质主要由细菌增殖造成。

In order to explore the effect of ultraviolet and microwave methods on the fresh noodles preservation and microorganisms inhibition, 9 kinds of noodles with different sizes were treated by UV and microwave methods in the present study. After the noodle were stored at 4 ℃ for 3days, the numbers of bacteria, fungi/yeast were detected respectively by the nutrient agar medium （NA） and potato-glucose-agar medium（PDA） and the colony morphology of microorganism was also analyzed. The result showed that microorganisms easily breed in 9# cooked noodle during the storage process. The different sizes of fresh noodle had influence on the colony growth, and 3# noodles had the largest number of colony with the number of bacterial was more than 108 per gram and the mold/yeast number was uncountable （P〈0.01）. There were mainly four forms of bacterial colonies in this study, and mold/yeast colonies were composed by four kinds of recognizable morphology colonies and secreted mucus colonies. The total bacterial count of fresh noodle treated by ultraviolet was （7.70×108） 1.38 times more than total bacterial count of the fresh noodle treated by microwave （5.54×108）. The inhibition effect on microorganism of microwave-preservation was superior to ultraviolet-preservation. The total bacterial count （7.70×108） was 3.34 times more than the amount of mycete （2.30× 108）, which meant that the deterioration of fresh noodles was mainly caused by bacterial but not mycete. The present study provided theory basis for the research on the fresh-keeping of noodles treated by ultraviolet or microwave, which had different size and metamorphic microbial flora.