Assessment of Storage-Induced Quality Changes in Freeze-Dried Chicken Liver and Heart Protein Hydrolysates Produced by Lactobacilli Fermentation

Abstract

The present study evaluated the storage stability of Lactobacillus helveticus (NCDC-292) fermented, freeze-dried chicken liver and heart protein hydrolysates. The resulting chicken liver hydrolysate powder (CLHP) and chicken heart hydrolysate powder (CHHP) were stored aerobically in PET jars at room temperature (27 ± 2°C) and analyzed over a 90-day period at 30-day intervals. Parameters assessed included pH, water activity, lipid oxidation, antioxidant activity, and microbial load. No significant changes in pH were observed throughout the storage period. However, water activity and TBARS values increased significantly (P < 0.05). Lipid oxidation remained within acceptable limits. Antioxidant activity, measured via DPPH and ABTS assays, declined significantly (P < 0.05) over time. A gradual increase in microbial counts was observed after the first 60 days, although the values remained within permissible limits. Overall, significant (P < 0.05) changes were observed in the quality attributes of both hydrolysates during aerobic storage. These findings highlight the necessity for enhanced packaging solutions to maintain the physicochemical and functional integrity of CLHP and CHHP, thereby supporting their potential use as functional food ingredients.