Degradation of aflatoxin B1 in dried figs by sodium bisulfite with or without heat, ultraviolet energy or hydrogen peroxide

Abstract

Dried fig fruits were spiked to contain 250 ppb aflatoxin B1 (AFB1) and treated with sodium bisulfite (1% in the aqueous phase of the mixture). This treatment caused 28.2% of added toxin to degrade in 72 h at 25°C. When hydrogen peroxide (H2O2, 0.2% in the aqueous phase) was added 10 min before the bisulfite treatment, 65.5% of added toxin was degraded in 72 h. In both instances, most of the degradation occurred during the second day of treatment. Heating bisulfite-treated samples at 45 to 65°C for 1 h caused up to 68.4% of added AFB1 to be degraded. Ultraviolet radiation (from a low-energy source) degraded 45.7% of AFB1 in fig samples that were treated for 30 min; the rate of degradation was not enhanced when bisulfite or H2O2 was present during this treatment.