| heal.abstract |
Strains of the Lactobacillus sakei/curvatus group, mainly non-slime-producing Lact. sakei, dominated the microbial flora of industrially manufactured taverna sausage, a traditional Greek cooked meat, stored at 4 degrees C and 10 degrees C in air, vacuum and 100% CO2. Atypical, arginine-positive and melibiose-negative strains of this group were isolated. The isolation frequency of Lact. sakei/curvatus from sausages stored anaerobically was as high as 92-96%, while other meat spoilage organisms were practically absent. Conversely, in air-stored sausages, leuconostocs, mainly Leuconostoc mesenteroides ssp. mesenteroides, had a considerable presence (14-21%), whereas Brochothrix thermosphacta, pseudomonads and Micrococcaceae grew, but failed to increase above 10(5) cfu g(-1) in all samples during storage. Only yeasts were able to compete against LAB and reached almost 10(7) cfu g(-1) after 30 d of aerobic storage at 10 degrees C. The great dominance (> 10(8) cfu g(-1)) of LAB caused a progressive decrease of pH and an increase of the concentration of L-lactate, D-lactate and acetate in all sausage packs. The growth of LAB and its associated chemical changes were more pronounced at 10 degrees C than 4 degrees C. At both storage temperatures, L-lactate and acetate increased more rapidly and to a higher concentration aerobically, unlike D-lactate, which formed in higher amounts anaerobically. Storage in air was the worst packaging method, resulting in greening and unpleasant off-odours associated with the high acetate content of the sausages. Carbon dioxide had no significant effect on extending shelf-life. The factors affecting the natural selection of Lact. sakei/curvatus in taverna sausage are discussed. Moreover, it was attempted to correlate the metabolic activity of this group with the physicochemical changes and the spoilage phenomena occurring in taverna sausage under the different storage conditions. |
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