Review of fruits flavor deterioration in postharvest storage: Odorants, formation mechanism and quality control

Comprehensive Evaluation of the ‘Shixia’ Longan Quality under Postharvest Ambient Storage: The Volatile Compounds Played a Critical Part

“…Fruit is a kind of popular food product appreciated for its appealing color, fragrance, and taste, as well as its unique nutritional properties and high flavor quality [14]. Recently, due to the augmentation of consumer awareness in all aspects associated with fruit quality, quality control of preharvest or postharvest fruit has become an issue of major importance.…”

“…Moreover, it has been found that the increase in esters may lead to 'overripe' odor, among which ethyl acetate has been studied as an off-flavor indicator of fruit anaerobic metabolism [38]. Alternatively, acids can emit a powerful sour-rancid odor that has a negative impact on the quality of fruit flavor, especially acetic acid that has the characteristics of 'sharp, pungent, sour' odor [14]. Hence, the significant change in odor profile during longan fruit spoilage suggests a joint influence by the decrease in aromatic substance (β-ocimene) and the increase in specific off-odor components (alcohol, acid, and esters).…”

“…Changes in the proportion of the composition and categories of volatiles during postharvest handlings will profoundly alter the fruit odor. The onset of pronounced off-flavor generally indicated a significant deterioration of fruit flavor [14]. For a better understanding of the volatile profile in longan during storage, an e-nose equipped with several electronic gas sensors was applied to test the complex chemical constituents, and the results were presented with an LDA (Figure 4a).…”

“…As one of the major quality aspects, flavor consists of taste and odor that have a direct impact on the individual purchase preferences of consumers [13]. However, the flavor quality of fruits may generally decline rapidly and undergo the processes of flavor loss as well as the production of off-flavor during the postharvest period [14]. Longan fruit, one of the typical non-climacteric fruits, is prone to rot and deteriorate in the postharvest stage manifested by pericarp browning and aril breakdown, along with the production of an unpleasant and strong off-odor, especially during storage under an ambient environment [7].…”

“…It is easily perceived by humans, which makes it an important indicator for consumers to evaluate the quality and freshness of fruit [13,20]. Those volatiles emitted by fruits may undergo transformation during postharvest storage by reflecting in the degradation of the original characteristic aroma of the fruit or leading to an increase in the content of off-odor substances [14]. Longan fruit, usually eaten fresh, bears a succulent, sweet, and aromatic flavor but without apparent aroma, which makes people pay far too little attention to the volatile compounds to ignore the severe off-odor produced by the fruit during postharvest storage.…”