Pistachio skin phenolics are destroyed by bleaching resulting in reduced antioxidative capacities.

Seeram NP, Zhang Y, Henning SM, et al. 

J Agric Food Chem. 2006;54:7036-40.

Raw nuts preserved phenolic levels and antioxidant capacity better than roasted nuts, suggesting contributing effects of other substances and/or matrix effects that are destroyed by the roasting process. The destruction of bioactive phenolics in pistachio skins may negatively impact the potential health benefits arising from pistachio consumption.

Read the Abstract