Enhancing the Hygienic Quality of Some Ghanaian Food Products by Gamma Irradiation

摘要

The microbiological quality (microbial load and profile) of 6 Ghanaian food products was determined before and after irradiation (0 kGy, 5 kGy, 7.5 kGy, 10 kGy) using standard microbiological methods. The microbial load was estimated by the total viable count (TVC) and moulds and yeasts count (MYC). The range of TVC and MYC of the un-irradiated products were 103 cfu/g - 106 cfu/g and 0 cfu/g - 106 cfu/g respectively. Un-irradiated Banku Mix Powder, Fermented Maize Powder and Cassava Dough Powder had relatively low microbial load (TVC ? 6.1 × 103 cfu/g; MYC ? 4.9 × 102 cfu/g). Un-irradiated Fermented Maize Dough, Kokonte Powder and Cassava Dough had relatively high TVC of >106 cfu/g. Eleven and 3 microbial isolates were detected in the un-irradiated and irradiated products respectively and the most common were Aspergillus niger and Bacillus spp. Irradiation dose of 10 kGy eliminated all microorganisms from the products. Doses of 5 and 7.5 kGy reduced the microbial loads of the products by approximately 1 to 6 log cycles to meet national and international standards. The use of low dose gamma radiation by the local food industry could improve the hygienic quality, extend shelf-life and enhance the competitiveness of the Ghanaian food products in domestic and export markets.