Microbial and sensory quality changes in refrigerated minced goat meat stored under vacuum and in air

Abstract

Goat mince was packed and stored at 4 ± 1°C. Mince was analysed physico-chemically and microbiologically at intervals 0, 3, 7, 10, 21 and 28 days for packs stored aerobically and 7, 14, 21, 28 and 40 days for vacuum packs. Although the initial pH of mince was 6.5, meat pH and extract release volume declined during vacuum storage. The microbial profile of aerobically stored mince was significantly higher than that in vacuum packs. The mean count of total aerobes of aerobic packages was higher than that of different groups of spoilage flora in vacuum packed mince. The air packed mince comprised the climax population (log 10 cfu g −1) of aerobic plate counts (9.0), psychrotrophs (8.8), coliforms (6.0), enterobacteriaceae (6.0), Pseudomonas (9.0), faecal streptococci (6.8), lactic acid bacteria (3.5), staphylococcal counts (5.5) and yeast and mould (4.0) counts, whereas bacterial (log 10 cfu g −1) profile of vacuum packed mince included total aerobic plate counts (7.0), psychrotrophs (7.1), Pseudomonas (7.6) faecal streptococci (7.3) and lactic acid bacteria counts (3.1). The shelf-life was 28 days for vacuum packed mince whereas similar overall acceptability scores were observed at 3 days for aerobic packages. During storage putrid odours in aerobically packed mince and sulphide odours in vacuum packs were observed. High pH of mince and the initial heavy carcass contamination promoted the rapid multiplication of facultative anaerobes leading to spoilage of the mince.