Effect of carboxymethyl cellulose edible coating enriched with Zataria multiflora essential oil on the quality and shelf-life of fresh pistachio (Pistacia vera L.) fruit

Background: Fresh pistachio can be affected by physiological and biochemical changes both during harvest and after harvest, and its optimum duration of storage cannot therefore be prolonged. Materials and methods: In order to maintain the quality of fresh pistachio fruits (Pistacia vera L. Ahmad-Aghaei), carboxymethyl cellulose at different concentrations accompanied by different concentrations of Zataria multiflora essential oil was used to produce an edible coating. The effects of these combinations were examined on the quality, shelf life, and sensory properties of the fresh fruitduring a storage period of 32 days (3±1°C, 85±5% RH). Results: The results of sensory and instrumental tests during storage on days 8, 16, 24, and 32 showed that coated samples with 1.5% (w/v) carboxymethyl cellulose used in combination with Zataria multiflora essential oil had the longest shelf life compared to the other treatments. Among the treatments containing 1.5% (w/v) carboxymethyl cellulose, the lowest weight loss and the highest kernel carbohydrate, total soluble solid, phenolic compounds, and antioxidant activity were observed in the treatments containing 1.5% (w/v) carboxymethyl cellulose accompanied by 0.4% (w/v) and 0.2% (w/v) Zataria multiflora essential oil. Conclusion: Application of 1.5% (w/v) carboxymethyl cellulose in combination with 0.4% (w/v) and 0.2% (w/v) Zataria multiflora essential oil effectively maintained the quality of fresh pistachio during the 32 days of storage.