Influence of Lactobacillus curvatus and Lactococcus lactis subsp. lactis on the shelf life of sausages in vacuum packaging

Abstract

Boiled meat products, including sausages, are perishable items, making them potentially hazardous and requiring the use of preservatives. Promising preservatives for sausages include starter cultures of lactic acid microorganisms, which act as antagonists to pathogenic and opportunistic bacteria. Therefore, this study aimed to determine the types of microbiota causing spoilage of sausages during storage in vacuum packaging and the effectiveness of their treatment with a starter culture of Lactobacillus curvatus or a mixture of starter cultures of Lactobacillus curvatus + Lactococcus lactis subsp. lactis. On the first day of storage, the dominant microorganisms in the sausages were Klebsiella variicola and Bacillus amyloliquefaciens plantarum. By the 21st day of storage, signs of sausage spoilage were observed, including the appearance of cloudy juice and the separation of the vacuum packaging. The main microorganisms causing sausage spoilage were Moellerella wisconsensis, Proteus mirabilis, and Bacillus cereus. In the control sausages on the 18th day, the number of mesophilic aerobic and facultative anaerobic microorganisms approached the allowable limit, and they were not suitable for further storage. Treatment of sausages with a starter culture or a mixture of Lactobacillus curvatus + Lactococcus lactis subsp. lactis led to an increase in the number of mesophilic aerobic and facultative anaerobic as well as lactic acid microorganisms practically throughout the entire storage period. However, signs of spoilage in both treatment groups appeared on the 36th day. Both treatments with starter cultures extended the shelf life of sausages in chilled conditions by 12 days. The use of a mixture of starter cultures for treating sausages during storage in vacuum packaging was not advisable. The obtained results can be used to extend the shelf life of boiled meat products, taking into account the species composition of spoilage microbiota.