Abstract

Introduction: Pistachio butter is one of the products of pistachio processing industry that has a high nutritional value as well as high added value. Materials and Methods: In this original study, pistachio butter produced under different conditions of temperature, grinding time, and sugar-to-honey ratio was evaluated in terms of oxidation (acidity, peroxide value and anisidine value). Pistachio butter samples were stored in a refrigerator (4 °C) for 6 months. Sampling time was in the time period of zero to six and with an interval of two months. Results: In investigating the optimal points, the acid value of four treatments (containing 10% honey) confirmed the mutual intensification property existing between temperature and grinding time and sugar-to-honey ratio. The use of low temperatures and grinding times as well as the usage of honey instead of sugar in the composition of pistachio butter reduced the acid value in the treatments. With increasing the time and temperature of grinding, the peroxide value increased and the highest peroxide value was observed in 6 hours and a temperature of 45 °C. The anisidine value increased with increasing temperature and grinding time in all samples of pistachio butter. Moreover, the anisidine value increased significantly with increasing the sugar-to-honey ratio in all samples. Conclusion: Pistachio butter containing honey has less oxidation than pistachio butter containing sugar.