Abstract: This study monitored the evolution of bacterial diversity, physicochemical properties, and volatile organic compounds (VOCs) in vacuum-packaged low-temperature emulsified sausages during 20 days of storage at 4 ℃. The results demonstrated that the physicochemical properties progressively deteriorated during the storage period, manifested by a decrease in pH, a* value, L* value, springiness, toughness, and hardness and an increase in b* value and thiobarbituric acid reactive substances (TBARS) value (P < 0.05). During days 0-15 of storage, Acinetobacter calcoaceticus and Brochothrix thermosphacta predominated in vacuum-packaged sausages, whereas on day 20 Rahnella aquatilis and Carnobacterium divergens absolutely predominated. A total of 55 VOCs were identified during storage, with the contents of ketones, aldehydes, alcohols and acids showing an overall increasing trend. Correlation analysis between bacterial succession and VOCs revealed that B. thermosphacta, A. calcoaceticus, R. aquatilis, and C. divergens were all significantly positively correlated with over five spoilage-related VOCs (e.g., 2,3-butanediol, 1-octen-3-ol, ethanol, benzaldehyde, and acetic acid) (|r| ≥ 0.80, P < 0.05) , and were predicted to be specific spoilage organisms (SSOs) in the sausages stored at 4 ℃. This study provides a theoretical basis for the effective control of SSOs in low-temperature emulsified sausages during storage.

Key words: vacuum packaging; low-temperature emulsified sausage; bacterial diversity; volatile organic compounds; specific spoilage organisms