Composite coating of xanthan gum with sodium nitroprusside alleviates the quality deterioration in strawberry fruit

Strawberry is an important and highly nutritious fruit crop that undergoes various postharvest qualitative losses. Therefore, the present study aimed to assess the synergistic effect of xanthan gum (XG) coatings with sodium nitroprusside (SNP) on the antioxidant defense system of strawberries during 16 days of storage by dipping method. The results on the 16th day of storage revealed that in comparison to control, the composite coating of XG 0.50 % + SNP reduced fruit weight loss (31.35 %) and spoilage incidence (87.22 %), along with effectively delayed respiration rates (16.44 %). Furthermore, the coatings maintained the biochemical properties of fruit including soluble solids content (7.05 %), titratable acidity (30.05 %), total flavonoid content (31.05 %), total anthocyanins content (17.59 %) and total phenols content(38.20 %) as compared to untreated fruit. The XG 0.50 % + SNP coated fruits also registered significantly (p < 0.05) higher total antioxidant activity (TAA) and antioxidant enzyme activities including catalase), peroxidase, and phenylalanine ammonia-lyase throughout the storage. Additionally, functionalized coating of XG with SNP suppressed the activity of polyphenol oxidase (PPO). This study proved that the application of coating of XG 0.50 % + SNP 2.0 mM is a potential treatment to preserve the postharvest quality of strawberries.