Interventions to minimise postharvest losses, ensure the quality and safety of tropical and subtropical fruits: an overview

Fresh horticultural produce is highly perishable and global postharvest losses vary from 30 to 44%. Tropical and subtropical fruits are generally more perishable compared to temperate fruit crops. Reduction of postharvest losses will ensure food and nutritional security to the growing world population and mitigate climate change through reducing the usage of the land, water, and other natural resources. Amongst various causes of the postharvest losses in fresh horticultural produce, ethylene alone causes major postharvest losses. Ethylene triggers fruit ripening but also shortens storage life by promoting fruit softening, senescence, and deterioration of quality. Various approaches including storage atmosphere, removal of ethylene in the storage environment, inhibition of ethylene biosynthesis and action on tropical and subtropical fruits and their limitations will be discussed. The valuable effects of inhibiting ethylene biosynthesis in the fresh horticultural produce are nullified upon exposer of the produce to external ethylene during the postharvest phase. The beneficial role of inhibition of ethylene action and new ethylene antagonists to diminish the negative impact of ethylene on horticultural produce has been researched by my research group over two decades and will be discussed. Recently, we discovered that 1H-cyclopropabenzene (BC) and 1H cyclopropa[b]naphthalene (NC) antagonizes the ethylene action in horticultural produce in a similar mechanism to that of 1-methylcyclopropene (1-MCP). BC and NC are structurally different from 1-MCP and can be applied as fumigation, spray, coating, or waxing. Additionally, the safety of fresh horticultural produce including outbreaks, possible sources of horticultural produce contamination by human pathogens in preharvest, harvest and postharvest phases will be discussed. In conclusion, a holistic approach spanning from pre- and postharvest phases including effective management of ethylene, addressing issues of horticultural produce safety, minimising postharvest losses, and ensuring the quality have complementary roles to meet the requirements of domestic and international markets.