Physicochemical, Microstructural, and Protein Profile Evaluation of Fermented Sausages Using Aspergillus niger and Lactobacillus plantarum Starter Cultures

Fermented sausages are typically produced with Lactobacillus plantarum as a starter, while fungal starters such as Aspergillus niger also exhibit proteolytic activity and contribute to flavor. This study compared the effects of A. niger and L. plantarum on fermented chicken sausages over 0–3 days of fermentation. Physicochemical traits (cooking loss, water-holding capacity, pH, aw, color, texture profile, proximate composition), microstructure, and protein profile were evaluated. Significant differences (p<0.05) were observed, with A. niger producing sausages of higher texture values and more porous structures, while L. plantarum accelerated acidification and preserved color. Fermentation reduced pH (5.75 to 4.70), aw (0.90 to 0.85), lightness, redness, hardness, cohesiveness, springiness, gumminess, chewiness, and proximate content, but increased water-holding capacity, yellowness, and adhesiveness. SDS-PAGE showed stronger proteolysis in A. niger (lowest band 9–10 kDa) compared with L. plantarum (10–12.5 kDa). Overall, A. niger demonstrated potential as an effective starter, influencing both structural and physicochemical properties.