Psychrotrophic Bacteria in Sliced Ham

Abstract

Seventy-five samples of commercial sliced ham were examined on the contamination of psychrotrophic bacteria. The strains isolated from those samples were subjected to investigation of the optimal growth temperature and the enzymatic activities at different temperatures.It was found that both the total and the psychrotrophic bacterial counts were under 103per gram in most of the samples examined.The growth degree of the isolates was examined at 5, 15, 25, 30 and 37°C, and more than 90% of the strains tested showed the best growth between 15 and 30°C.Enzymatic activity of the isolates was examined at 25 and 5°C. At 25°C, production of lipase, protease and amylase was observed for 294 (70.6%), 93 (22.3%) and 19 strains (4.5%), respectively. On the contrary, at 5°C, 298 (71.6%), 231 (55.5%) and 5 strains (1.2%) produced lipase, protease and amylase, respectively. Protease-positive strains were predominant, especially, at low temperature.