The Effects of Solar Drying Systems and Packaging Types on the Quality Indicators of Dried Pistachio Nuts

Pistachio nuts are among the most popular nuts in the world. Some postharvest operations, such as drying and packaging could affect the final quality of the product. Therefore, the main objective of this study is to determine the most suitable packaging materials and drying methods for the safe storage of pistachios.

The effects of solar drying systems (methods I & II) and various types of packaging (Cellophane & Nylon) on the oxidative stability of pistachio oil were investigated. For this purpose, the peroxide value was evaluated at a 45-day interval at 25oC.

It was shown that solar drying systems and packaging types had meaningful and significant effects (p<0.05) on the hydro-peroxide forming of pistachio oil. According to the results obtained, the peroxide value was higher in pistachios dried using method I and packaged in cellophane films under atmospheric conditions (containing 21% O2+79% N2). In addition, the lowest peroxide value was observed in the samples dried using method I and packaged in nylon under vacuum conditions (containing 0% O2 + N2).

According to the results, the drying of pistachios using method II and packaging them in nylon under vacuum conditions maintained the quality of pistachios better and extended their shelf life