干浆米线的变质微生物及其污染源分析

Analysis of spoilage microorganism and pollution source of dry rice noodles

以某米线生产企业生产的变质干浆米线为研究对象,对其进行变质微生物检测及其污染源分析。研究表明:4份样品的微生物数量非常高,细菌总数在106—108cfu/g,霉菌数量在104cfu/g,酵母为103—104cfu/g。从微生物组成来看,细菌则主要是葡萄球菌属(Staphylococcus spp.),为凝固酶阴性,其可能来自操作人员体表或设备。霉菌主要是拟青霉(Paecilomyces spp.)、毛霉(Mucor spp.)、白地霉(Geotrichum candidum)和交链孢霉(Alternaria spp.);菌相组成与空气中主要的霉菌菌相一致,显示该污染的源头可能是空气。干浆米线虽经干燥,但水分活度不够低,易染菌,保质期短;在保鲜、干燥工艺上还待研究和改进。

This paper discusses several lots of dry rice noodles which were found deteriorated and analyses the spoil- age microorganism and pollution source of dry rice noodles. Studies showed that over 10^4--10^8 cfu/g bacteria were detected in all 4 samples. Fungi were also detected in all 4 samples with amount of 10^4cfu/g, as well as 10^3--10^4 cfu/g yeast. The main bacteria was Staphylococcus spp. , identified as coagulase-negative. They would be a poten- tial threat to food safety, and maybe came from body surface of operators or equipment. However, fungi were iden- tified primarily as Paecilomyces spp. , Rhizopus spp. , Geotrichum candidum and Alternaria spp. Its unique com- position of fungi was just the same as those of air, indicating that air was probably the pollutant source. The water activity of dry rice noodles was still not low enough to prevent microbial contamination. The preservation and drying technology of dry rice noodles still waited for further research and improvement.