Improving quality of greenhouse tomato (Solanum lycopersicum L.) by pre- and postharvest applications of hexanal-containing formulations

From harvest to consumption, tomato (Solanum lycopersicum L.) fruit are exposed to several exogenous factors that enhance product deterioration. Phospholipase D is a key enzyme involved in membrane deterioration that occurs during fruit ripening and senescence. Hexanal, an inhibitor of phospholipase D has been successfully used for pre- and postharvest treatment of fruit, vegetables and flowers. In this study, effectiveness of pre- and postharvest application of an aqueous hexanal formulation and an enhanced freshness formulation (EFF) containing hexanal and other ingredients were evaluated by monitoring changes in quality parameters during postharvest storage of greenhouse tomatoes. Tomatoes subjected to preharvest spray with EFF containing 1 mM hexanal twice a week had better colour, and firmness than untreated fruit and hexanal formulation treated fruit. EFF treated tomatoes also showed low hue angle values indicative of enhanced red colour. Preharvest spray with 1 mM hexanal twice a week resulted in higher levels of ascorbic acid and soluble solids in fruit than those subjected to EFF treatment, and the control. Postharvest dip application of harvested tomatoes in 2 mM hexanal as EFF resulted in enhanced brightness and hue angle values, reduced red colour, increased fruit firmness and ascorbic acid content after 21 days of storage, indicative of better quality. The results suggest that hexanal has the potential to enhance shelf-life and quality of greenhouse tomatoes. (C) 2014 Elsevier B.V. All rights reserved.