Understanding the deterioration of fresh brown rice noodles from the macro and micro perspectives

•Macro and micro changes occurred in FBRN during deterioration.•The TPC and MY counts increased, and the colony composition changed during storage.•The hydrolytic rancidity of lipids was caused by microbial growth during storage.•The water content and status changed and the edible qualities of FBRN worsened.•The TPC and MY counts play a key role in determining the deterioration of FBRN. The microbial compositions, quality characteristics, and structural changes in fresh brown rice noodles (FBRN) during storage were investigated. Total plate count and mold and yeast counts increased while the pH decreased during storage. Metagenomic sequencing revealed that the microbial composition of FBRN changed throughout storage. A comprehensive investigation of the variation in lipid content demonstrated that hydrolytic rancidity was responsible for lipid deterioration. LF-NMR showed an increase in the proportion of bound water and a decrease in the proportion of free water in FBRN. Moreover, significant changes in edible qualities were observed. The cooking loss increased three-fold and noodles hardness reduced by approximately 23%. Further, the high initial aldehyde content of FBRN diminished almost completely, while that of alcohols and esters increased, leading to significant flavor deterioration. The correlation and factor analysis suggested that the TPC and MY counts could be used as key indicators of FBRN deterioration.