Hexanal: A plant-based volatile for sustainable postharvest preservation of fruits and vegetables

Hexanal (C₆H₁₂O), a naturally occurring six-carbon aldehyde, has emerged as an effective bioactive compound for postharvest management of horticultural crops, addressing the critical issue of 25-50% postharvest losses in developing regions caused by pathogenic infections and physiological deterioration. This comprehensive review evaluates research findings on hexanal's applications in fruit and vegetable preservation through systematic analysis of controlled studies examining antimicrobial properties, physiological effects, and practical implementation strategies. Controlled studies demonstrate that hexanal treatments achieve 25-75% reduction in postharvest decay, extend storage duration by 20-180 days, and maintain nutritional quality across diverse horticultural commodities including tree fruits, berries, and vegetables. The compound functions through multiple pathways including direct pathogen inhibition, plant defense response activation, and cellular membrane stabilization, with demonstrated efficacy against major postharvest pathogens such as Botrytis cinerea, Penicillium expansum, and Rhizopus stolonifer. Treatment methods encompass foliar applications, postharvest dips, vapor fumigation, and controlled-release systems, with optimal concentrations ranging from 0.5-5.0 mM for liquid applications and 10-100 ppm for gaseous treatments. Current evidence supports hexanal's classification as Generally Recognized as Safe (GRAS), facilitating regulatory approval for commercial adoption, while economic assessments indicate favorable cost-benefit ratios of 3:1 to 8:1, particularly for premium horticultural products. Research gaps include standardization of treatment protocols, development of stable formulations, and optimization of delivery systems for large-scale operations, representing priority areas for future investigation to enable widespread commercial implementation of this sustainable preservation technology.