Assessment of synergistic effects of ultrasonication, ozonation and their combination with aloe vera active edible coating containing spirulina and turmeric extracts on preservation of fresh-cut apples.

Fresh-cut apples (FCA) are widely consumed due to their convenience and high nutritional value; however, their quality declines rapidly during storage due to enzymatic browning, microbial proliferation, oxidative reactions, and moisture loss. While edible coatings and non-thermal processing approaches have been studied independently for postharvest preservation of fresh-cut produce, their combined use along with natural bioactive compounds has received limited attention. Therefore, this study evaluated the effectiveness of a novel aloe vera gel-based active edible coating enriched with Spirulina platensis and turmeric extracts, applied alone (CT) or in combination with ultrasonication (US), ozonation (OZ), and their combined treatment (US + OZ) for preserving FCA at 4 °C for 42 days. Multiple quality parameters including weight loss, firmness, color attributes, physicochemical properties, antioxidant compounds, oxidative stress markers, enzymatic activity, microbial load, and overall acceptability were assessed throughout the storage. The coating treatment alone (CT) showed the most effective preservation, limiting weight loss to 4.58% after 42 days and maintaining firmness at 12.75 N, while the untreated control deteriorated rapidly with 17.41% weight loss and severe texture loss by day 14. Microbial growth remained minimal in CT (2.91 log CFU/ g total plate count; <2.5 log CFU/g yeast and mold). CT also preserved bioactive compounds with total phenolics (4.41 mg GAE/g), flavonoids (1.43 mg QE/g), and antioxidant activity (44.37% DPPH). The combined US + OZ-assisted coating treatment also exhibited strong preservation performance, particularly in maintaining firmness, reducing oxidative stress accumulation, and suppressing enzymatic browning-related activities. The improved preservation efficacy was associated with enhanced barrier properties of the coating matrix, reduced oxidative degradation, inhibition of browning-associated enzymes, and improved microbial control induced by the integrated non-thermal treatments. Overall, the aloe vera-based active coating, either alone or combined with mild US + OZ treatment, effectively maintained quality attributes and extended the storage stability of FCA up to 42 days compared with the rapid deterioration observed in untreated samples within 14 days. These findings highlight the potential of integrating natural bioactive coatings with non-thermal technologies as a sustainable preservation strategy for fresh-cut fruit applications.