Preparation process and quality analysis of fermented feed from residues after polysaccharide extraction of abalone viscera

Abalone viscera residues remaining after enzymatic extraction of polysaccharides are still rich in peptides and other nutrients. However, due to the complexity of deodorization processes and the risk of residual heavy metal contaminants, such residues are often discarded directly, resulting in low resource utilization efficiency. To enhance the added value of this by-product, we used abalone viscera residues after polysaccharide extraction supplemented with wheat bran, as a substrate for fermentation with Pediococcus acidilactici, Bacillus subtilis, and Debaryomyces hansenii. We determined the optimal fermentation parameters through single-factor experiments, developed a kinetic model to predict microbial growth, and evaluated the quality of the fermented product. The results show that under the conditions of 12% wheat bran addition and a solid-to-liquid ratio of 3:1, fermentation with P. acidilactici for 24 h achieved the highest degree of protein hydrolysis, reaching 34.56%. The nutritional quality of the fermented product was significantly improved: the total acid content increased to 1.24%, the peptide content rose to 64.69%, and the free amino acid profile was optimized. The constructed kinetic models for microbial growth and substrate consumption showed high fitting accuracy, with determination coefficients (r²) of 0.991. In conclusion, this study confirms that fermentation with P. acidilactici can effectively improve the quality and achieve high-value utilization of abalone viscera enzymatic hydrolysate residues, providing a feasible technical approach for its resource development.