Influence of regulated deficit irrigation and rootstock on the functional, nutritional and sensory quality of pistachio nuts

Abstract

The aim of this study was to determine the influence of rootstock and regulated deficit irrigation (RDI) on pistachio nuts, by studying their size, weight, color, fatty acids (gas chromatography with mass spectrometer detector), minerals (atomic absorption), total polyphenol content (TPC), antioxidant activity (ABTS, FRAP, and DPPH), and sensory properties (trained panel). Three rootstocks (P. atlantica, P. integerrima, and P. terebinthus) and three irrigation treatments (T0: fully irrigation, 100 % ETc; T1: during phenological phase II the stem water potential, SWP, was maintained around −1.5 MPa; and T2: during phase II, SWP < −2.0 MPa) were used. Pistachios obtained from P. terebinthus had the highest size, weight and oleic acid content (main fatty acid), while P. integerrima nuts had the best sensory profile. The use of moderate RDI (T1) led to pistachio nuts with higher weight, smaller size, similar fatty acid profile, higher TPC (1284 and 1192 g GAE kg−1 dry weigh, respectively), and similar (no statistically differences) antioxidant activity (AA) and sensory profile than control samples. Thus, moderate RDI produces nuts with a good functional quality (high values of TPC and AA), without affecting their sensory quality, but being environmental friendly and having reduced economic cost due to a lower use of irrigation water.