Microbiological and physico-chemical characteristics of stored <i>tsire-suya</i>, a roasted meat product

Abstract

The physico-chemical and microbiological characteristics of tsire-suya, a roasted meat product, stored at varying temperatures (4 oC, 28 oC, 40 oC, 50 oC, and 60 oC) for 5 days were studied. The bacteria isolatedinclude Bacillus subtilis, B. brevis, B. megaterium, Pseudomonas aeruginosa, Enterobacter aerogenes, Staphylococcus aureus, S. albus, Klebsiella sp, Acinetobacter mullei and Corynebacterium sp. The fungalisolates include Saccharomyces cerevisiae, Candida spp, Rhodotorula sp, Aspergillus niger, A. Fumigatus, Fusarium moniliforme, and Penicillium sp. Only Bacillus subtilis and B. megaterium, were isolated from tsiresuyastored at 50 oC and at 60 oC, and there were no physical signs of spoilage, unlike samples stored at 4 oC and 28 oC on which there was discolouration and production of off-odour on the 4th day and 2nd dayrespectively, and slime production on the 4th day in samples stored at 28 oC in addition to isolation of spoilage organisms like Pseudomonas and even pathogenic organisms like S. aureus. The microbial count decreased at all storage temperatures except at 28 oC where there was an increase. However, 50 oC and 60 oC were good for safe storage of tsire-suya as no spoilage organisms or pathogenic organisms were isolated at thesetemperatures. But we will recommend storage at 50 oC because samples here were not as hard as those stored at 60 oC. The usual practice of storing tsire-suya at 28 oC should be discouraged as the product is not safe and it is of poor quality when stored at this temperature. The development of the suya industry would be greatly enhanced by this study on time / temperature limits related to storing of tsire-suya.