<p>A&#xa0;novel guar gum hydrocolloid (GG-HC) coating formulation was prepared with glycerol including other additives (ascorbic acid and calcium chloride) to enhance the postharvest quality of mangoes. The guar gum coating formulation was optimized with the response surface methodology (RSM) using glycerol as a&#xa0;plasticizer, ascorbic acid as an anti-browning agent, and CaCl₂ as a&#xa0;cross-linking agent for improved postharvest quality of ‘Chaunsa’ mangoes. The effects of the main coating component concentrations— GG-HC (1–2%, w/v), glycerol (0.3–0.9%, v/v), ascorbic acid (1–1.5%, v/v), and CaCl₂ (1–2%, v/v)—were investigated for quality parameters, i.e., percent weight loss (PWL), pH, firmness, and total soluble solids (TSS) across 7&#xa0;days of storage at 35 ± 2 °C. The results showed that guar gum (1.5%), glycerol (0.6%), ascorbic acid (1%), and CaCl₂ (1.5%) were the best formulation. In addition, FTIR characterization of the fruit coating revealed major constituents of guar gum (galactose, mannose) with aliphatic C‑H stretching, hydroxyl OH stretching vibrations, and iteration of C‑OH stretching vibrations. Furthermore, SEM analysis displayed the surface micrograph transformed into a&#xa0;sheet-like structure with a&#xa0;spongy morphology. Through RSM, it was shown that the experimental data could be adequately fitted into a&#xa0;quadratic second-order polynomial model with a&#xa0;coefficient of determination (<i>R</i>²) ranging from 0.999 to 1&#xa0;for all the variables except TSS. In general, guar gum, glycerol, ascorbic acid interactions appeared to be the most significant factor influencing PWL, pH, and firmness, while no significant change was observed in TSS. Statistical analysis showed a nonsignificant difference between experimental and predicted values. Hence, the GG-HC coating formulation has the potential to extend the shelf-life and to maintain the quality of ‘Chaunsa’ mangoes during storage.</p> Graphic abstract <p></p>