Changes in Quality and Microflora of Lentinus edodes during Post-harvest Cold Storage

This study investigated the quality and microbial flora changes of Lentinu edodes during postharvest cold storage. L. edodes was picked with sterile gloves, treated with ozone and stored for up to 40 days at 2–4 ℃. The changes in the moisture content, color, texture, and volatile flavor substance, free amino acid and flavor nucleotide contents of the mushroom were determine during the storage period, and the changes in the microbial flora on the surface of L. edodes were detected by high-throughput sequencing. Besides, fungi were isolated and identified from the mushroom surface, and the dominant spoilage organisms were determined. The results showed that the moisture content, brightness (L* value) and hardness decreased with storage time, while the elasticity, chewiness, cohesiveness and gumminess increased first and then decreased. The relative contents of alcohols contributing to the clean aroma of L. edodes such as 1-octene-3-ol and 3-octanol increased first and then decreased during storage, and so did the contents of umami, sweet and bitter amino acids. The contents of 5’-cytidine monophosphate (5’-CMP), 5’-uridine monophosphate (5’-UMP) and 5’-guanosine monophosphate (5’-GMP) decreased continuously, while the contents of inosine 5’-monophosphate (5’-IMP) and adenosine 5’-monophosphate (5’-AMP) increased first and then decreased. The richness of the microbial community decreased first and then increased, whereas the diversity increased first and then decreased. Pseudomonas was found to be the dominant spoilage bacteria. The major spoilage fungi were Trichoderma harzianum, Alternaria and Aspergillus flavus. In conclusion, the quality and microbial flora of L. edodes changed obviously during postharvest cold storage, which will provide a theoretical basis for further controlling the spoilage and prolonging the storage period of L. edodes.