Potential application and mechanism of hexanal in extending shelf life and safety of tropical fruits: A systematic review

Post-harvest losses of tropical fruits have profound implications for food security and food safety. Hexanal has demonstrated high efficacy in reducing post-harvest losses, and extending the shelf life of temperate fruits. The protective effects of hexanal on tropical fruits are limited. The present review investigated the influence of hexanal treatment on the extension of shelf life in tropical fruits. A systematic review was conducted to collate existing data pertaining to hexanal treatment, its impact on the shelf life and safety of tropical fruits, and its potential mechanism of action. Literature was examined via electronic databases such as Google, Google Scholar, PubMed, and SCOPUS, spanning the period from 2012 to 2024. The findings revealed that hexanal application, at both pre- and post-harvest, had the potential to extend the shelf life, and enhance the safety of tropical fruits. Hexanal exhibits favourable effects on the physicochemical and microbial parameters during fruit storage. It was found that the effectiveness of hexanal treatment varies across species. To date, there is insufficient evidence that differentiates between tropical and temperate fruits in response to hexanal. It is suggested that the mode of action of hexanal in extending the shelf life is by affecting the calcium ion channel generating calcium signalling, subsequently inhibiting the expression of ripening-related genes such as phospholipase D. Hexanal implementation showed promising result for prolonging fruit shelf life. The transcriptomic and metabolomics studies provided information on how ripening is regulated, which is important for future shelf-life improvement through gene modification.