Shelf life extended: Focus on microbiota identification, nutrition value, color difference and lipid oxidation of puffed bean products

Abstract

Puffed bean products(PBP)contain a large amount of protein, and are susceptible to microbial contamination or harmful substances during storage and processing. In this study, the migration rule of microbial quantity and basic index during storage of the same batch and taste PBP was analyzed, and the spoilage bacteria in different periods of PBP were identified and analyzed by high-throughput DNA sequencing (HTS) The results showed that the peroxide value, acid value and mold count of PBP did not exceed the Chinese national standard, and the peak heights of the functional group characteristic peaks in different periods did not change significantly, further indicating that the degree of oxidation of fats and oils in the PBP was relatively light. During storage, the total colony count of PBP increased rapidly in the first two weeks, and controlling the microbial count of the products is the key to extend the shelf life of PBP. Bacterial colonisation affected the alkaline nitrogen and free amino acid content, resulting in a small increase in content. There was no significant change in the content of water activity this may be related to the choice of vacuum packaging for PBP. The brightness value in the colour difference value increased and the redness value decreased this may be related to the high temperature during the high temperature refining process of the chilli seasoning, the high temperature destroys the pigment in the chilli. The dominant bacterial genera of puffed soya products within shelf life were Pantoea, Streptococcus, Kocuria and the dominant fungal genera were Altemaria, Aspergillus. The dominant bacterial genera of expired samples were Bacillus, Rhodococcus. The main dominant fungal genus was Aspergillus. Results of the study will help to better control the growth of microorganisms in the future, as well as to improve the shelf-life and taste of the products.