Effects of Different Preservation Treatments on Quality of Wet Rice Noodles and Microbial Diversity of Spoiled Samples

This study aimed to evaluate the quality changes and the growth of microorganisms of wet rice noodles with different preservation treatments during storage at 25 ℃, and analyzed the microbial diversity of spoiled samples based on Illumina Miseq high-throughput sequencing. The results indicated that the shelf life of control sample (CK) was only one day. The rice noodles became sticky and edible quality decreased significantly. Compared to the control, the shelf life of wet rice noodles treated by acid leaching (CA), acid leaching & ε-polylysine hydrochloride (PL), acid leaching & water bath (SY) could be extended to 2, 4 d and 13 d, respectively, and the main spoilage feature was mildew, differ from the control sample, which became sticky and smelly. The results of 16S rDNA indicated that the dominant spoilage bacteria in CK group were Pantoea, Sphingomonas and Bacillus. Different preservative treatments could significantly reduce the diversity of bacterial community. Among which, CA reduced the relative abundance of Sphingomonas and Bacillus, significantly. PL had good inhibitory effect on all three dominant bacterial genuses. ITS rDNA results showed that Rhizopus, belongs to Mucoromycota, was the dominant spoilage fungi in CK, however the relative abundance decreased to less than 0.1% after preservation treatments. While Ascomycota, with strong resistance to stress, became the dominant phylum after preservation treatments. This study provides a theoretical basis for the exploration of preservation technology of wet rice noodles.