Oxidative Stability of Pistachio (Pistacia vera L.) Paste and Spreads

In this study, pistachio (Pistacia vera L.) spread was prepared using pistachio paste, icing sugar, and red palm oil. Pistachio paste, pistachio spread without emulsifier, and pistachio spread with 1.5 % monoglycerides (Dimodan HP-M, Danisco, Malaysia) were investigated to determine their oxidative stability by subjecting them to accelerated autoxidation conditions (60 A degrees C). Pistachio paste and pistachio spread exhibit a great susceptibility to lipid oxidation due to their high-fat content. However, it was found that the high oleic and palmitic contents of the oil increase its stability. In all the pistachio products examined, Totox values were higher than 10 (the maximum permitted level) after 25 days of storage. In none of the products was (E,E)-2,4-decadienal detected on day 0. After 25 days of storage, however, the peak area percentages rose to 0.13, 0.19, and 0.18 in pistachio paste, pistachio spread without emulsifier, and pistachio spread with emulsifier, respectively. Based on color investigations, the a value (i.e., less greenish) was increased in all the pistachio samples at the end of the storage period. Based on the results obtained from sensory evaluations as well as GC-MS, free fatty acid (FFA), and color measurements, it may be concluded that the shelf life of pistachio products is 20 days at 60 A degrees C.