Effect of gamma irradiation on microbial quality of minimally processed carrot and lettuce: A case study in Greater Accra region of Ghana

• The microbial load on the cut-vegetables was beyond acceptable level for consumption.
• The microbial contamination of carrot was found to be higher than that of lettuce.
• 2 kGy was most appropriate in treating cut-vegetables for microbial safety.

The effect of ionizing radiation on the microbiological quality on minimally processed carrot and lettuce was studied. The aim was to investigate the effect of irradiation as a sanitizing agent on the bacteriological quality of some raw eaten salad vegetables obtained from retailers in Accra, Ghana. Minimally processed carrot and lettuce were analysed for total viable count, total coliform count and pathogenic organisms. The samples collected were treated and analysed for a 15 day period. The total viable count for carrot ranged from 1.49 to 14.01 log10 cfu/10 g while that of lettuce was 0.70 to 8.5 7 log10 cfu/10 g. It was also observed that total coliform count for carrot was 1.46–7.53 log10 cfu/10 g and 0.14–7.35 log10 cfu/10 g for lettuce. The predominant pathogenic organisms identified were Bacillus cereus, Cronobacter sakazakii, Staphylococcus aureus, and Klebsiella spp. It was concluded that 2 kGy was most effective for medium dose treatment of minimally processed carrot and lettuce.