Abstract

The survival and production of aflatoxin by Aspergillus flavus introduced into pasteurized (85°C;15 min) and unpasteurized orange juice treated with Aframomum danielli (local preservative) extracts at 0, 1, 2, 3, 4, 5 and 6% concentrations were investigated at 3 and 7 days of storage on shelf (28±2°C). There was slight increase in pH on day 3 which was more prevalent on day 7(4.77-6.85 and 6.07-7.37) for the pasteurized and unpasteurized orange juice respectively. There was no significant difference (p≥0.05) in growth and aflatoxin levels on day 3, however, luxuriant growth of A. flavus (0.63-1.42 g and 0.52-0.68 g) and aflatoxin production (29-156 ng/ml and 5.40-63.00 ng/ml) were recorded on day 7 respectively. The pasteurized sample (0%; control) of A. danielli had the highest growth and aflatoxin level followed by the sample with 6% extract with the same trend in unpasteurized juice. A. danielli at very low concentration showed effective inhibition of A. flavus growth and produced low levels of aflatoxin. 1% showed effective inhibition of A. flavus growth in both while 2 and 3% produced low levels of aflatoxin for pasteurized and unpasteurized products respectively.

Key words: Aframomum danielli, Aspergillus flavus,  aflatoxin, orange juice, pasteurised.