A three-dimensional-simulation-assistant optimization of heat transfer and the influence of hot water treatment on postharvest quality, volatile flavor compounds and cuticular wax metabolisms of three cultivar mangoes.

A three-dimensional-simulation-assistant optimization of heat transfer in three cultivars ('Jinhuang', 'Guifei', and 'Tainong') of mango fruit with distinct sizes during postharvest hot water treatment (HWT) was investigated. Through temperature field simulation and experimental verification, the maximum temperature disparity between peel and core reached 26.66 °C. Maintenance of temperature field of peel at 52 °C during HWT significantly delayed the mango ripening. HWT enhanced the fresh and sweet flavor mainly by regulating dynamic changes of key volatile substances such as elevating 3-hexen-1-ol, 2-hexenal, benzene, 2.3-butanedione, and butanoates in 'Jinhuang', increasing retention of 3-hexen-1-ol, nonanal and α-gurjunene in 'Guifei', and enriching 3-hexen-1-ol, α-pinene and butanoates in 'Tainong'. HWT made wax ultrastructure smoother, reduced pores, and significantly increased aldehyde substances. Transcriptomic profiling revealed the up-regulated CYP77A3 and FAR1 associated with the wax biosynthesis pathway by HWT. The results provide a promising application of HWT as a green and eco-friendly postharvest fruit preservation technology.