This research study investigates the substantial impact of utilizing biodegradable, eco-friendly, and even edible coating films derived from whey proteins on extending the overall shelf life and improving various quality attributes of Golden Delicious apples. The samples underwent meticulous evaluation through the utilization of a digital fruit sclerometer and a portable digital refractometer. The results obtained during cold storage conditions demonstrated a slight yet notable increase over a duration spanning from 2 to 5 months following treatment with whey proteins. Furthermore, the weight loss of the sample exhibited a significant variation, shifting from an initial figure of 6.8% to a lower value of 5.75%. Additionally, the acidity and firmness of the sample underwent considerable modifications, changing from 20 to 6.5% and from 0.5 to an impressive 0.005, respectively. The comprehensive findings of this study strongly indicated that whey proteins present a highly suitable source for coating various vegetables and fruits, thereby effectively enhancing the overall shelf life of the product.

Potato is a widely consumed staple crop prone to postharvest deterioration and quality loss. Biodegradable edible coatings offer an eco-friendly alternative to conventional packaging for extending shelf life. This study evaluated the effectiveness of whey protein concentrate (WPC) based coatings, with and without chitosan, in maintaining potato quality under different storage conditions and durations. Tubers were treated with WPC coating (WC1) or WPC–chitosan coating with additives (WC2) and stored at room temperature (RT, 24 °C), refrigeration (RF, 4 °C), or incubator (IC, 20 °C) for up to 48 days. Dry matter (DM), firmness (FR), and total soluble solids (TSS) were determined every 8 days. DM ranged between 17.3–20.7%, FR between 5.6–8.1 N, and TSS between 3.4–5.3 °Brix. Storage period (SP) had the strongest influence, with DM peaking after 16–24 days, FR gradually decreasing, and TSS dropping sharply after 32 days. Coating did not significantly affect DM, but WC2 improved FR retention while slightly lowering TSS. RF best preserved FR and TSS, whereas RT and IC accelerated quality loss. Overall, WPC-based coatings, particularly WC2, provide a biodegradable and effective strategy to reduce postharvest losses, maintain potato quality, and support sustainable food preservation.