Enhancement of the flavor compound 3-Methylbutanal and sensory quality in sausages fermented by Lactococcus lactis CGMCC 31087: Leucine and α-Ketoglutaric acid as supplements.

This study investigated the effects of α-ketoglutaric acid (α-KG) and leucine (Leu) supplementation on 3-methylbutanal abundance by Lactococcus lactis CGMCC 31087. Leu was kept constant, while α-KG concentrations varied across three models: PBS model, minced meat, and fermented sausage. In the PBS model, increasing α-KG (0.1 to 1 mM) raised both 3-methylbutanal and glutamic acid levels, but no further increase in 3-methylbutanal occurred in 10 mM α-KG group. In minced meat, 3-methylbutanal initially rose with α-KG (5-10 mM) but then fell at higher concentrations (20-40 mM). Excessive α-KG lowered pH in both minced meat and sausages, inhibiting microbial growth and Leu utilization. The highest 3-methylbutanal concentration (133.73 μg/kg) in sausages occurred with 3 mM α-KG, enhancing umami taste, aromas, and texture. These findings suggest that an optimal Leu-to-α-KG ratio facilitates 3-methylbutanal production and sensory quality, providing a potential strategy for improving flavor development and accelerating ripening in fermented meat products.