Effect of Nanoencapsulated Pistachio Green Hull Extract in the Carboxymethyl Cellulose and Soy Protein Isolate Edible Coatings on Shelf-Life Quality of Fresh Pistachio

Abstract

This research was aimed at investigating the effect of edible coatings based on the combination of carboxymethyl cellulose (CMC) and soy protein isolate (SPI) containing 0.0%, 1.0%, 2.0%, and 3.0% w/v of nanoencapsulated pistachio green peel extract (PGPE) on the chemical and microbiological properties of raw pistachio of Kale Ghoochi variety during 18 weeks of storage at 27 ± 1°C. Moisture content (MC), acid value (AV), peroxide value (PV), total phenol content (TPC), total viable count (TVC), and total fungi count (TFC) were tested at 21-day intervals. PGPE contains phenolic compounds (48.73 mg GAE/g) with antioxidant activity (IC₅₀ = 10.83) which increased MC (19.51%) and TPC (75.62%) of coated samples with 3% PGPE compared with control, whereas AV (41.12%), PV (53.16%), TVC (44.64%), and TFC (35.01%) reduced (p < 0.05). The results of this research suggested that the edible coatings based on the combination of CMC and SPI containing nanoencapsulated PGPE have the ability to reduce the oil oxidation reactions and microbial growth in raw pistachio. Therefore, the concentration of 2.0% nanoencapsulated PGPE due to its better properties can be used to extend the shelf life of raw pistachio.