Physical, compositional and sensory differences in nuts among pistachio (Pistachia vera L.) varieties

Differences in some physical, compositional and sensory characteristics among eight varieties of pistachio nuts (Aegina, Pontikis, Bronte, Cerasola, Joley, Kerman, Mumtaz and Sirora) from different origins were studied. The evaluated varieties were cultivated under the same field conditions and the dried nuts were utilised. The percentage of split nuts ranged from 93.8% (Sirora) to 80.2% (Aegina), the 10-nut weight from 15.23 g (Kerman) to 9.7 g (Cerasola), the kernel/nut percentage from 57.24% (w/w) (Pontikis) to 47.08% (w/w) (Kerman) and the ratio of length/width of nut from 1.81 (Aegina and Joley) to 1.56 (Mumtaz). Colour measurements showed the highest shell L* (80.26) for Kerman, the lowest shell h° (81.19) for Mumtaz, the lowest kernel membrane h° (24.43) for Cerasola, and the highest h° (107.23) on the inner kernel of Aegina. Crude protein content varied between 21.87 (Cerasola) and 18.99% d.w. (Joley), and the fat between 57.62 (Joley) and 49.79% d.w. (Cerasola). Among the major fatty acids in kernel oil, oleic ranged from 67.86% in Cerasola to 51.6% in Kerman, linoleic from 27.03% in Kerman to 11.56% in Pontikis and palmitic from 10.24% in Kerman to 8.54% in Cerasola. Linolenic acid was highest in Kerman (0.5%). Myristic, palmitoleic, stearic, vaccenic, arachidic and gondoic acids were also found in all samples. Negative and significant linear correlations were found between oleic and linoleic, and between mono- and poly-unsaturated fatty acids. Most of the physical and compositional characteristics measured were affected significantly by variety. Panelists preferred nuts of big size with a naturally yellowish shell colour. Visual differences in kernels were not significant, whereas Kerman, Sirora and Cerasola gained the panelists’ overall flavour preference among the varieties evaluated.