Comparison of pistachio (Pistacia vera L.) kernel volatile compounds of “Siirt”, “Uzun” and “Kirmizi” grown in Turkey: Effect of traditional and industrial in‐shell roasting

Abstract

AbstractThe aim of this study was to compare pistachio (Pistacia vera L.) kernel volatile compounds (VCs) of “Siirt”, “Uzun” and “Kirmizi” cultivars grown in Turkey, and also to determine the effects of traditional and industrial in‐shell roasting. The VCs were analyzed by using solid phase microextraction and gas chromatography–mass spectrometry. Regardless of cultivar, a total of 36, 55, and 65 VCs were identified in raw, industrial and traditional roasted pistachios, respectively. Limonene was the major terpene and the most important volatile compound in “Siirt” and α‐pinene in raw “Kirmizi” and “Uzun” but α‐terpinolene in their roasted counterparts. The heterocyclic and phenolic compounds reached a maximum in all three cultivars in traditional roasting compared to industrial roasting. Discriminant analysis based on volatile compounds classified the pistachios according to the roasting methods rather than cultivars. “Kirmizi” may be the most promising cultivar for traditional roasting regarding its highest pyrazine content.Practical ApplicationsThe main object of the present study was to determine and compare volatile compounds (VCs) in three different pistachio (Pistacia vera L.) cultivars (“Siirt”, “Uzun” and “Kirmizi”) that are raw (not roasted), industrial and traditional roasted in‐shell. They are the main cultivars grown in Turkey. VCs from kernels were analyzed by using solid phase micro‐extraction and gas chromatography–mass spectrometry. VC profile and its abundance were dependent on both roasting methods and cultivar. Pyrrole, pyrazine and furan compounds were emerged by the roasting process. Pyrroles were higher than pyrazines in industrial roasting, with exception of “Kirmizi” but pyrazines were the highest heterocyclic compounds in traditional one, even being the dominant VC group in “Siirt” and “Kirmizi”. Roasting process was a crucial factor for pyrazines, pyrroles, furans, phenolic compounds and also terpenes in “Siirt,” “Uzun” and “Kirmizi” pistachios. “Kirmizi” may be the most promising cultivar for traditional roasting regarding its highest pyrazine content.