Active Edible Coating to Preserve Fresh Figs

Abstract

The present study aimed to evaluate the effects of active edible coating (AEC) on fresh fruits to extend the shelf life (15 days) and maintain their nutraceutical content by minimizing the rate of respiration and reducing the water loss. The coating efficacy was enhanced with the addition of active compounds extracted from agriculture by-products, such as pomegranate peel, olive leaf, and chestnut bark. In particular, a high efficiency in preserve the nutraceutical characteristics was obtained when figs were coated with the following active polysaccharide edible mixture: 70/30 Alginic acid sodium salt (viscosity 20-40 cps, 1% in H2O)/ Pectin from the citrus peel (low degree of esterification), added with 0.5% Olive Leaf Extract (OLE), prepared as described (Volpe et al., 2014). The safeguard of nutraceutical content was monitored in the two weeks following the fruit harvest by measuring total phenols and flavonoids amounts and specific bioactive phenolic compounds. For comparison, figs in polypropylene containers, wrapped in the micro-perforated film (UN-FIG), as normally marketed, and figs treated with an edible coating (EC) without biomolecules were prepared and analyzed. The results showed a decrease of about 15% of phenols and flavonoids content in UN-FIG after 15 days to time 0, while AEC induced a slight but significant increase compared to UN-FIG and EC-FIG samples after 15 days. The results obtained regarding the biochemical characterization demonstrated the ability of the active coating, particularly OLE, to contain the decay of the quality and functional characteristics of figs during storage.