Effects of sonication and yeast fermentation on the physicochemical and sensory features of duck liver paste

Non-fatty duck liver (DLv) shows excellent nutritional properties, but the predominance perception of off-odor has limited the general consumption and processability. Ultrasonic (US)-assisted yeast fermentation strategies were explored to alleviate off-odor perception of DLv, including US-treated DLv, US-stressed yeast strain, and a combination of both before yeast fermentation. Interestingly, the combination of US-treated DLv and US-stressed yeast significantly increased ω-3 fatty acids, improved textural stability, and reduced water activity and TBARs during fermentation. Meanwhile, total biogenic amine contents were controlled at a low level dominantly attributed to yeast-driven spermine and spermidine metabolism under fermentation. Multivariate and discriminant analysis recognized aroma compounds including formic acid, 3-methyl pentyl ester, benzaldehyde, 2-methyl-hexanoic acid, (E, E)-2, 4-decadienal, phenylethyl alcohol, 2-phenyl-2-butenal, octanoic acid and hexanoic acid as the major contributors driving the shift of volatile fingerprinting patterns toward those with lower off-odor perception. These results suggested great potential of ultrasonication-assisted fermentation in achieving physicochemical quality control and alleviating off-odor perception, providing a novel approach to improve the quality and sensory attributes of animal liver-based products in the food industry.