Phenolic and triterpenoid composition and inhibition of α-amylase of pistachio kernels (Pistacia vera L.) as affected by rootstock and irrigation treatment

The current water scarcity forces farmers to adopt new irrigation strategies to save water without jeopardizing the fruit yield and quality. In this study, the influence of 3 regulated deficit irrigation (RDI) treatments and 3 rootstocks on the functional quality of pistachios were studied. The functional parameters studied included, polyphenols, triterpenoids, and inhibition of alpha-amylase. The results showed that P. terebinthus and P. atlantica rootstocks led to pistachio kernels with higher contents of polyphenols and triterpenoids (mainly betulinic acid with 111 and 102 mu g g(-1), respectively) than pistachios obtained using P. integerrima rootstock (81 mu g g(-1)). On the other hand, the use of moderate RDI (T1 treatment) increased the total content of polyphenols (similar to 10%), quercetin-O-galloyl-hexoside (similar to 15%), keampferol-3-O-glucoside (similar to 19%), and polymeric procyanidins (similar to 20%), as compared to the control trees, resulting in pistachios with a better functional profile, lower economic cost and with a lesser environmental impact.