The effects of gamma irradiation (GR) on total phenol, anthocyanin
and antioxidant activity were investigated in three different Persian
pistachio nuts at doses of 0, 1, 2 and 4 kGy. The antioxidant activity,
as determined by FRAP and DPPH methods, revealed a significant
increase in the 1–2 kGy dose range. Total phenol content (TPC)
revealed a similar pattern or increase in this range. However, when
radiation was increased to 4 kGy, TPC in all genotypes decreased.
A radiation dose of 1 kGy had no significant effect on anthocyanin
content of Kale-Ghouchi (K) and Akbari (A) genotypes, while it
significantly increased the anthocyanin content in the Ghazvini (G)
genotype. In addition, increasing the radiation to 4 kGy significantly
increased the anthocyanin content of K and G genotypes. To conclude,
irradiation could increase the phenolic content, anthocyanin and
antioxidant activity of pistachio nuts.