Investigation of solid-state fermentation of red seaweed (Pyropia spp.) with lactic acid Bacteria: Effects on protein profile and in vitro digestibility

This study aimed to investigate the effects of solid-state fermentation (SSF) on the protein profile and digestibility of red seaweed (Pyropia spp.). The results indicated that compound lactic acid bacteria (LAB) performed better than a single strain in terms of growth and metabolism on the red seaweed substrate. Specifically, the simultaneous inoculation of Lactobacillus reuteri and Lactobacillus paracasei (at a 1:2 ratio) for 3 days significantly increased the soluble protein content in red seaweed than other inoculation schemes. Under these conditions, more free peptides were detected in the SSF samples. Among these, 58 peptide segments were predicted to have biological functions. Furthermore, SSF samples were more easily digested by gastric and intestinal fluids in vitro which led to higher antioxidant activity in the digesta. Overall, this study provides valuable insights into enhancing the nutritional value and functional properties of seaweed, contributing to the development of seaweed-processed products for food applications.