Xanthan gum coating delays ripening and softening of Khalal-stage date palm (Phoenix dactylifera) fruit by modulating cell wall metabolism and antioxidant system activity

Date palm is a climacteric fruit, and its ripening is triggered by stimulated ethylene production when harvested at the khalal stage, resulting in cell wall polysaccharide degradation and prompt textural changes. In this study, the impact of xanthan gum [0, 0.1, 0.2, and 0.3% (XGC)] as an exogenous coating in regulating date palm fruit ripening and softening was studied for 12 d and 40 d during storage at 20 °C and 5 °C, respectively. Exogenous XGC suppressed fresh weight loss, ethylene production, respiration rate, and oxidative stress attributes, while preserving antioxidant system activities. The XGC-treated date palm fruit exhibited higher firmness and showed reduced pectin methylesterase (PME), cellulase (CX), β -galactosidase ( β -gal), and polygalacturonase (PG) activity. Additionally, exogenous XGC-treatment revealed lower accumulation of water-soluble pectin (WSP) and exhibited higher Na 2 CO 3 -soluble pectin (NCSP), protopectin (PrP), chelate-soluble pectin (CSP), hemicellulose (HLS), and cellulose (CLS) contents. The total soluble solids (TSS) remained persistently lower, along with substantially higher total flavonoids (TFC), total phenolics (TPC), ascorbic acid (AsA) content, and titratable acidity (TA) in XGC-coated date fruit. In conclusion, XGC coating could be considered an eco-friendly and effective postharvest treatment for delaying ripening and softening of date palm fruit harvested at the khalal stage.