Study of Ahmad aghaei pistachio storage with citric acid, ascorbic acid, polyethylene and polystyrene pack

Pistachio is one of the most popular nuts in the world because of its taste and nutritional properties. Mostly, its consumed dry in harvest period. Major factors limiting for shelf life of pistachios are browning and water accumulation. In this study, the effects of citric acid (1, 1.5 and 2%) and ascorbic acid (15, 25 and 35 ppm) and two types of plastic packs (polyethylene and polystyrene) on storage life (days 0, 25 and 45), Ahmad aghaie pistachio was studied. According to panelists, the use of acid treatments for 25 day of storage was able to maintain the appearance and taste characteristics of pistachio and since then there was no significant difference between treatment and the control sample. Pistachios treated with 15 ppm ascorbic acid in polystyrene pack were more favorable in appearance and browning than polyethylene pack. The maximum of phenol was related to ascorbic acid treatments (15 ppm) in polyethylene pack. Anthocyanin and chlorophyll amount decreased during storage, but carotenoids first increased and then decreased. Pistachio pigments such as chlorophyll, anthocyanin and carotenoids were preserved in polyethylene packages than polystyrene. Citric acid treatment (1.5%) had the maximum percentage of fat. Overall, the polyethylene pack and ascorbic acid 15 and 25 ppm and citric acid 1.5% concentration maintained the qualitative and quantitative properties of pistachio.