Methyl jasmonate enabled maintained the postharvest flavor quality of ginger (Zingiber officinale roscoe) by reducing the loss of terpene volatile compounds

Ginger, as a globally vital medicinal and food homologous crop, plays an irreplaceable role in human diet and healthcare. However, during the storage of ginger, the decline of physical properties and degradation of volatile flavor quality have emerged as an industrial concern that severely restricts the market value of the product. MeJA plays an essential role in extending fruit shelf life and regulate the synthesis of volatiles in horticultural products, yet its application in ginger remains unreported. This study investigated whether MeJA could delay the deterioration of external quality and the loss of volatile compounds, thereby maintaining the flavor quality of ginger during storage. The results demonstrated that MeJA retarded weight loss, moisture reduction, texture softening, and color darkening in ginger rhizomes during storage. In addition, dynamic profiles of volatile compounds in the postharvest stage of ginger rhizomes were characterized via HS-SPME/GC-MS methodology. A total of 67 volatile components were identified and quantified precisely, which were divided into terpenes, alcohols, esters, aldehydes, ketones, and others. Terpenes represented by zingiberene, farnesene, β-sesquiphellandrene, α-curcumene, (E)-β-farnesene, and β-elemene, was the most abundant classification of compounds in ginger, comprising approximately 70 % of the total content. Compared with the control group, MeJA reduced the loss rate of total quantity and total content of volatiles, while effectively slowed the loss of various volatiles, especially after 35d of storage. Furthermore, 30 characteristic components with an odor activity values (OAVs) ≥ 1 were identified, predominantly exhibiting spicy, green, floral, fatty, and fruity fragrances. It is noteworthy that the most prominent scent of ginger is the spicy aroma, which can be significantly up-regulated by MeJA. Moreover, MeJA treatment was found to enhance the expression levels of terpene-related genes in ginger. This study clarified the patterns of variation in physical properties, volatile compounds, and aroma intensity during the storage of ginger, providing a theoretical basis for mitigating the deterioration of flavor quality in ginger rhizomes during postharvest storage. This research holds significant importance for promoting the comprehensive utilization and high-quality development of ginger.