Abstract
Strawberry fruits have a very short shelf-life owing to their high degree of perishability. This study aimed to determine the efficacy of chitosan (CH) incorporated with olive oil residues (OOR) coatings on overall quality of cold-stored strawberry fruits compared to watery wax incorporated with thiabendazole. Strawberries were sprayed after infected with Rhizopus stolonifer with six different coating formulas and uncoated fruits. Indeed, all freshness and microbiological parameters were significantly increased in uncoated fruits compared to coated fruits. Amazingly, the coated strawberry using CH-OOR 2% was reduced significantly the gradual decline in their contents of total phenolics, flavonoids and their antioxidants. Likewise, it was the lowest fruits in decayed area, fungal count and malondialdehyde development. Then, fruits were coated with CH-OOR showed uniform coating distribution, since it was impossible to see any pores. Therefore, coating treatments with CH-OOR was improved the membrane integrity and increased the keeping quality.
PRACTICAL APPLICATIONS
Edible coatings could be an effective way for delaying the ripening process and extending the shelf-life stability of strawberry during postharvest. The effectiveness of chitosan (CH)-olive oil residue (OOR) as a novel edible coating, in comparison with watery wax-thiabendazole was approved. The applicability of those films to maintain microbiological and freshness quality in strawberry during postharvest was succeed. Incorporation of OOR into CH increased its antifungal property against R. stolonifer in vivo and in vitro. Coating by CH-OOR reduced phenolics, flavonoids and antioxidants decomposition in coated fruits compared to uncoated. CH-OOR was able to slow down the gas exchange by reducing the CO2 of coated strawberry, which reduced their malondialdehyde development. Commercially, CH-OOR could be explored as a novel and potential natural coating to substitute the synthetic agents in fruit packaging industries. The coating cost could increase the total cost about 6-8% where shelf-life and keeping quality was improved.