Physical treatments to control postharvest diseases of fresh fruits and vegetables

Physical treatments have gained great interest in recent years to control many postharvest diseases in fruits and vegetables because the total absence of residues in the treated product and minimal environmental impact. The present review shows the extensive research work conducted during many years and increased in the last 10 years, developing physical means for consistent disease control. The review include the use of cold storage as the main physical method for delaying or reducing biotic and abiotic diseases. Physical treatments, like heat, including hot water and hot air treatments, radio frequency and microwave, hypobaric and hyperbaric pressure and far ultraviolet radiation (UV-C light), are treated as promising control means, and controlled and modified atmospheres as complementary physical tools essential to reduce or delay the development of postharvest pathogens. A particular emphasis is given to the mode of action, which involve direct effect to the pathogen (lethal or sub-lethal) of spore germination and mycelial growth of fungi and the resistance induction in the host which is not well known but nowadays, with the new tools available in molecular biology will be easy to highlight other physiological and biochemical pathways on which the phenomenon are based. Besides benefits of treatment in different commodities, also limitations of use, including low persistence, risk of adverse effects and technological problems for commercial application are discussed.