Effects of irradiation and chemical preservatives on the microbiological quality of refrigerated fresh-cut mangoes.
Gasu E. K., Appiah V., Gyamfi A. A., Nketsia-Tabiri J.
Author Affiliation: School of Nuclear and Allied Sciences Atomic Campus, University of Ghana, Accra, Ghana.
European Journal of Food Research & Review 2 : 101-110
Abstract : Fresh-cut mangoes are nutritious and offer consumers freshness, flavour and convenience. They however have a shorter shelf life compared to whole fruits due to their high susceptibility to microbial contamination. The effects of gamma irradiation and chemical preservatives on the microbiological quality of refrigerated fresh-cut mangoes were evaluated. Well matured fruits of Kent and Keitt varieties sliced into cubes were microbiologically analysed initially to determine counts of total viable cells (TVC), coliforms, Salmonella sp., Staphylococcus aureus and Escherichia coli. The samples were subjected to various irradiation doses (0, 1.0, 1.5, 2.0 and 2.5 kGy) and chemical preservatives (sucrose, citric acid, sodium benzoate and a combination of these chemicals in equal proportions) and stored at 6°C and 10°C for 15 days. TVC was subsequently estimated at 3-day intervals for the treated samples. TVC was estimated as 3.53±0.25 and 4.86±0.38 log10 cfu/g for the Kent and Keitt varieties respectively. No coliforms Salmonella sp., E. coli or S. aureus were detected in both varieties. Irradiation at doses of 1.5 kGy to 2.5 kGy in combination with storage at 6°C was able to eliminate all viable cells after 9 days compared to 12 days of storage at 6°C in the case of chemical preservatives. Irradiation is more effective and ideal compared to chemical preservatives in improving the microbiological quality and therefore extending the shelf life of refrigerated fresh-cut mangoes.