<p>Pectin’s anionic heteropolysaccharide structure makes it suitable for coating metal nanoparticles (MPNs) by preventing their accumulation, and improves MPNs’ acceptability to formulate edible coatings. The present investigation explored the efficacy of guava-derived pectin-based zinc oxide (ZnO) and copper oxide (CuO) nanocomposite biopolymer coatings on the quality attributes and shelf-life extension of berries. The solvent casting and chemical reduction methods were used to synthesize guava-derived ZnO and CuO nanoparticles coatings, respectively. Simultaneously, berries were submerged in three different biopolymer coatings, viz., guava-derived pectin (GDP), GDP/ZnO, and GDP/CuO for three minutes and stored at refrigerated temperature (i.e., 7&#xa0;°C) along with uncoated samples. The samples were evaluated for physicochemical changes and sensorial parameters at an interval of 2 days for a 19-day storage period and FTIR spectroscopy. The nanocomposite coatings were effective in reducing the berries’ weight loss, water activity, and minimizing the reduction in pH and titratable acidity. Comparably, an increase in total soluble solids (TSS) was observed in all coated samples, but it was lower than uncoated ones. Furthermore, compared to controlled and other coated samples, only ZnO-coated berries retained their texture, odor, and were of acceptable quality to a lesser extent until 19 days of storage. The results of FTIR spectroscopy reveal the presence of alcohol and carboxylic acid groups in the GDP structure. Antibacterial assay showed that ZnO nanoparticles showed a stronger zone of inhibition than CuO nanoparticles, thereby aiding in improving the shelf life of grapes. Supposedly, nanocomposite coatings could be harnessed as an active biopolymer packaging material that can prolong the lifespan and maintain the quality of grapes for an adequate period (at least two weeks) under refrigerated conditions.</p>