Natural coatings and essential oils effects on postharvest quality and antioxidant system of organic avocado (Persea americana Mill. 'Hass')

Avocado (Persea americana Mill.) is a commodity highly consumed in America since the pre-Hispanic age. Mexico is the major producer globally with the highest share in the organic market of tree fruits. The most critical food losses in the supply chain take place between farm and fork, due to a lack of, or inadequate strategies oriented to preserve quality and prolong shelf life of vegetable products. Recent evidence support that the application of natural coatings or the use of essential oils (EO) could contribute significantly to preserve quality and extend shelf life of different crops during storage. The objective of this work was to evaluate the application of a commercial organic coating (Natural NDASH Shine 505-OR^®) in combination with oregano and thyme essential oils (3 and 5 mL L^‑1) on avocado postharvest quality (firmness, weight loss, internal and external color) along with total soluble phenols (TSP) and flavonoids (TSF) contents, and its relation with antioxidant capacity (DPPH and ABTS methods) during cold storage at 6°C for 21 days. The application of coatings, with or without EO, showed a 1.5% reduction of weight loss and results on 6 fold firmness values compared with control fruits (without natural coating). No positive correlations of secondary metabolites content like TSP and TSF with antioxidant activity were observed in treated fruits. Nevertheless, antioxidant capacity levels did not exhibited nominal reductions during storage at the reported conditions of this work. The application of natural coatings contributed positively to maintain quality parameters and antioxidant activity of organic avocado.