Integrated technological process of postharvest treatment of fruits for the control of rot, with no use of agrochemicals

Abstract

The present project proposes to provide an innovative technological process, alternative to the use of agrochemicals, and to validate a pilot fruit postharvest treatment equipment. The process combines physical methods (hydrothermal treatment by spraying and irradiation with UVC light) with ozonated water application to control postharvest diseases of mango, orange, melon, and papaya. In order to prolong the residual period of control, ozonized mineral oil and edible coatings based on carboxymethylcellulose and chitosan impregnated with mesoporous silica containing natural bioactive compounds, will, also, be evaluated. The motivation for the development of this technology lies in the demand of producers, exporters, and consumers of fruit, for effective treatments to control rot, which maintain the freshness and quality of the fruit, and that are safe and clean, without the use of fungicides and other chemical compounds that leave toxic residues harmful to health. The physical methods are proven to be effective to control microorganisms, besides acting positively on the physiology of the fruit, not only delaying biochemical processes of maturation and senescence, but also inducing mechanisms of resistance against the attack of phytopathogens, prolonging the shelf life of the fruit. Ozone is highly reactive and has high oxidative power with germicidal effect three thousand times higher than chlorine's. Two ways of ozone application will be evaluated, one by dipping the fruit in ozonated water and the other by spraying ozonated mineral oil, which allows the ozone to remain free and active on fruit surface for at least 40 days. Edible coatings based on carboxymethylcellulose and chitosan with mesoporous silica, besides prolonging the fruit shelf-life safely, allow the immobilization and release of essential-oil based bioactive compounds, in a controlled way, extending the period of control efficiently. (AU)