Lipid characterization of local pistachio germoplasm in central and southern Tunisia

Abstract

Pistachio germoplasm cultivated in traditional areas of Tunisia presented an interesting genetic diversity. The study was conducted to assess desirable biochemical characteristics from the rich local germoplasm in pistachio ecotypes. Kernel samples of the widely cultivated Mateur cultivar and 89 ecotypes from Sfax and El Guetar localities were collected during 2 years. Oil content and fatty acid composition were assessed. Fat content and fatty acid composition differed significantly among local ecotypes. The mean fat content of pistachio ecotypes ranged from 56 to 78%. Palmitic acid content varied between 7.1 and 12.9%. In addition, stearic acid was found as a minor saturated fatty acid in pistachio kernels; levels varied from 0.7 to 2.8%. Oleic acid content ranged from 56.1 to 80.7% with a significant difference over the different ecotypes. Linoleic acid varied between 8.2 and 29.7%. Mateur cultivar showed slight variations of fat content and fatty acid composition in the localities investigated. Certain ecotypes, such as Loby7 (fat content 78.5%), Sridique1 (80% Oleic, 9% linoleic), Ibala3 (76.8% oleic, 9.5% linoleic) from Sfax, and EPE2 (80% oleic, 8.2% linoleic), BMS3 (79.4% oleic, 9% linoleic), HAB3 (78.6% oleic, 9.9% linoleic), AMMS4 (78% oleic, 11.2% linoleic), and ABT2 (76.8% oleic, 12.1 linoleic) from El Guetar oasis, were distinguished by the interesting oil quality compared with Mateur and foreign cultivars. These results offer opportunities for further genetic improvement of pistachio oil quality.