Effect of Roasting on Oxidative Stability of Pistachio Nut

Abstract

Pistachio nut (Pistacia vera L.) is one of the most delicious and nutritious nuts in the world. Roasting process enhances the flavor, color, and texture of pistachio nuts and increases overall palatability of the valued products. Oxidative stability is also an important parameter for the quality assessment of pistachio nuts. The main objective of this study is to determine the effect of roasting on the oxidative stability of pistachio samples. For this purpose, pistachio kernels are roasted with two steps industrial roaster at different temperature; 110-120, 130-140, 150-160° C. Rancimat Method, which is one of the Accelerated Shelf – Life Test (ASLT) method, was used to determine the oxidative stability of raw and roasted pistachio nut kernel. The induction time (IT) of raw and roasted pistachio samples were automatically recorded at 100, 110, and 120°C. As the temperature increased induction time was significantly decreased during ASLT (p<0.05). The roasted pistachio sample was higher IT than IT of raw pistachio sample. Although increasing the oxidative stability with increasing roasting temperature, very high roasting temperature (150-160°C) decreased IT. As a result, roasting of pistachio nuts improved the oxidative stability of the nut.

Keywords: Pistachio nut, roasting, oxidative stability, Rancimat method

DOI: 10.7176/JSTR/5-5-14