Relationship between Aspergillus flavus growth and aflatoxin B1 and B2 production with phenolic and flavonoid compounds in green hull and kernels of pistachio cultivars

Contamination to Aspergillus flavus and aflatoxin is a significant and chronic threat of pistachio production, consumption and exportation in the world. The aims of the present study was evaluation of resistance of pistachio cultivars (Shahpasand, Abbasali,Kale-ghouchi, Khanjari, Akbari and Pesteh-garmeh) and relationship between total phenolic content (TPC) and total flavonoid content (TFC) of green hull and kernels, as antioxidant, to A. flavus growth and aflatoxin production. Inoculation of pistachio kernels was done by 2×106 spores of toxigenic A.flavus and aflatoxins (B1 and B2), TPC and TFC of the green hull and kernels were measured by HPLC, Folin-Ciocalteu and aluminum chloride method, respectively. Results showed that Pesteh-garmeh and Akbari cultivars and Shahpasand with the lowest and highest percent colonization of A. flavus and aflatoxin production in kernels were respectively resistant and susceptible and other cultivars were intermediate. TPC and TFC were higher significantly in resistant cultivars than susceptible. A negative correlation was observed between TPC, TFC and aflatoxin content in kernel and green hull of pistachio cultivars, as well as TPC, TFC and A. flavus growth. These findings show the role of TPC and TFC in resistance of pistachio cultivars with contamination to A. flavus growth and aflatoxin production.