Physical, chemical and microbiological characteristics of fermented surimi with Actinomucor elegans

•Changes of surimi during fermentation with Actinomucor elegans were investigated.•Fermentation changed the physiochemical and texture properties of surimi.•Molecular weight distribution and amino acids analysis revealed protein degradation.•It was advisable to control the fermentation time in the first stage to be 36 h.

The physical, chemical and microbiological changes of surimi during surimi pehtze preparation stage, with Actinomucor elegans XH-22 (A. elegans XH-22) as fermentation starter, were investigated. Enzyme assay showed that A. elegans XH-22 could continuously produce protease and α-amylase on surimi surface. Texture profile analysis (TPA) indicated that fermentation for 48 h decreased pH and moisture content and modified the texture properties of surimi. Increases in amino nitrogen and trichloroacetic acid-soluble nitrogen (TCA-N) contents revealed obvious surimi protein degradation, which was further confirmed by size-exclusion HPLC analysis of surimi water soluble protein. Fermentation significantly increased the content of free amino acids and enriched special amino acids such as histidine, phenylalanine and glutamic acid, which could influence the nutritional and sensory properties of fermented surimi product. Considerable levels of aerobic plate count, spores and LAB were detected during the fermentation process. It is thus, from a public health point of view, advisable that the fermentation time in the first stage be controlled to be within 36 h. This research gives a new clue for improving the utilization of low-value fish.