Volatile organic compounds (VOCs): Biomarkers for quality management of horticultural commodities during storage through e-sensing

Plants emit various volatile organic compounds (VOCs) during the developmental stages of growth, and as responses to the various abiotic and biotic stresses. During postharvest storage, horticultural commodities can undergo its natural metabolisms like senescence, sprouting, ripening, and may be infected with various groups of microorganisms. These commodities may undergo various temperatures, relative humidity, water, and other abiotic stress conditions during preharvest and post-harvest conditions, and will behave differently than the normal crop, and follow a separate biochemical pathway, leading to change in the VOC profile. These VOCs can act as the signature of a particular state of storage material; therefore classified as the biomarkers in postharvest storage management. The biotic or abiotic stresses are completely responsible for the stimulation of specific VOC emission and are the attributing factors for the uncertainty in the case of VOC release during storage. This review focused mainly on the grouping of VOCs emanating from horticultural commodities during post-harvest storage, their classification linked to various abiotic and biotic factors, and their application in e-sensing for nondestructive quality monitoring. This will justify the implementation of the VOC-biomarker method as a technique to detect the quality of horticulture crops in commercial storage.