Pages: (20-36 )
Abstract
Food contamination by aflatoxigenic Aspergillus and consequent production of aflatoxins remain a significant threat to food safety. This has led to the continual search for plants with antifungal and anti-mycotoxigenic potencies for controlling moulds in food commodities. Aqueous extract of Piper guineense (Ashanti pepper, AP) was evaluated for antioxidant activity and inhibitory potential against growth and aflatoxin production in nine strains of aflatoxigenic Aspergillus [A. flavus (n = 4) and A. parvisclerotigenus (n = 5)] grown on neutral red desiccated coconut agar (NRDCA) for 5 days. Liquid chromatography tandem mass spectrometric analysis of 3 mm agar plugs from the inoculated AP-amended NRDCA treatments showed variable levels of aflatoxin inhibition. The 0.5% (v/v) AP extract inhibited AFB1 in A. flavus by 91.1–99.7%, and by 57.8–95.6% in A. parvisclerotigenus. Inhibition of the different types of aflatoxins correlated significantly (AFB1/AFG1: r = 0.87, p = 0.003; AFB1/AFM1: r = 0.94, p = 0.0001; AFG1/AFM1: r = 0.86, p = 0.005). However, there was no inhibition of fungal growth at all tested concentrations of the extract though the antioxidant levels of the spice were appreciably high. This study reveals the suppressive effect of P. guineense aqueous extract on aflatoxin biosynthesis.
Keywords: Aflatoxin; Aspergillus; metabolites; spices; toxigenicity.,