Amelioration of sodium alginate- CNC edible coating with thyme and/ or clove essential oil for post-harvest quality of guava

The effect of sodium alginate- crystalline nanocellulose based pickering emulsion containing different concentrations of thyme and clove essential oils on post-harvest storage life and quality of guava fruits under ambient condition was assessed. The guavas were coated by dipping in respective emulsions and evaluated at 3 days interval upto 12 days ambient storage period. The emulsion and films were evaluated for physical and chemical properties, whereas coated and uncoated guavas were evaluated for the physiological properties. The average droplet diameters of nanoemulsions were in the range of 342.4–476.8 nm, increasing with concentration of essential oil in the formulation, whereas the emulsions remained stable without phase separation till 28 days. Higher antioxidant and antifungal activity was observed in coating emulsions of clove essential oil as compared to thyme essential oil. Highest retention of ascorbic acid and firmness of 86.2% and 44% was obtained in formulations TC_0.05 as compared to 68.4% and 23% in uncoated fruits during the 12 days storage period.