Effects of trans-2-hexenal and cis-3-hexenal on post-harvest strawberry

Abstract

Green leaf volatiles are emitted by green plants and induce defence responses. Those with antifungal activities in plants may replace chemicals as natural post-harvest treatments. We investigated the postharvest treatment of strawberry with trans -2-hexenal and cis -3-hexenal and observed a decrease in the mould infection rate. To determine the volatiles’ functions, we conducted a component analysis of the volatiles released from trans -2-hexenal-treated strawberry and analysed gene expression. Several acetates, which were expected to be metabolites of trans -2-hexenal in fruit, were released from treated strawberry; however, these acetates did not inhibit fungal growth. The gene expression analysis suggested that postharvest strawberries were not protected by jasmonic acid-mediated signalling but by another stress-related protein. Harvested strawberries experience stress induced by harvest-related injuries and are unable to perform photosynthesis, which might result in different responses than in normal plants.

Trans-2-Hexenal-Based Antifungal Packaging to Extend the Shelf Life of Strawberries

“…Likewise, HxAc and HxnAc increased by one order of magnitude in the active packages on day 2 and remained high until day 6. This agrees with the results of Wakai et al, who described the formation of these two acetates and the significant reduction of HXAL after treatment [15]. They also proved that the two acetates were less active against Botrytis cinerea than they were against HXAL.…”

“…The analysis of these samples using GC-MS revealed the formation of two by products, 2-hexen-1-ol acetate (HxnAc) and hexyl acetate (HxAc). Both are compounds identified in strawberries [15,23] and are responsible for the scents of strawberries and banana, respectively. Additionally, both are additives approved by the FDA as fragrant and flavoring agents that impart freshness to flavors with fruity nuances [24,25].…”

“…Strawberries are a source of bioactive compounds with antioxidant properties [11], but they also release substantial amounts of metabolites, including some with antimicrobial activity against Botrytis cinerea (trans-2-hexenal (HXAL), hexanal, 1-hexanol, (E)-2-hexen-1ol, hexanone, nonanal, (Z)-6-nonenal, (E)-3-nonen-2-one, 2-nonanone, methyl salicylate, and methyl benzoate) [12,13]. HXAL has been reported as an organic compound that berries release as a response and defense against the infection Botrytis cinerea [14,15]. Furthermore, C-6 aldehydes, at sub-lethal concentrations, affect the protein expression of the mold [16].…”

Identification of VOCs in essential oils extracted using ultrasound- and microwave-assisted methods from sweet cherry flower

“…Benzaldehyde was detected in four sweet cherry cultivar flowers and hyacinth, citronella, cinnamon, iris and rose. Moreover, (E)-2-hexenal has a fresh green leaf fragrance and can be used as a blending fragrance for essential oils and various floral fragrances 42 . Acetaldehyde is also present in the aroma of four sweet cherry cultivar flowers and naturally exists in round pomelo, pear, apple, raspberry, strawberry, pineapple, coffee, and orange juice 43 .…”

Plant volatile organic compound (E)‐2‐hexenal facilitates Botrytis cinerea infection of fruits by inducing sulfate assimilation

“…A low concentration of vapour concentration of 4.96 µg l −1 of ( E )‐2‐hexenal increased colony growth and spore germination of the fungus Botrytis cinerea , although the underlying mechanisms were unclear (Neri et al ., 2015). By contrast, a high concentration of ( E )‐2‐hexenal can inhibit fungal disease development (Wakai et al ., 2019), and it therefore has been developed as a fungicide to control fungal diseases in crops and fruits (Ma et al ., 2017; J. Zhang et al ., 2017). The sensitivity of different plant pathogenic fungi to ( E )‐2‐hexenal varies (Gardini et al ., 2001; Neri et al ., 2006; J. Zhang et al ., 2017).…”