Post-harvest ultraviolet irradiation induces changes in physical-chemical properties and levels of polycyclic aromatic hydrocarbons and gene expression in mulberry fruit.

Abstract

Earlier studies reported that post-harvest ultraviolet (UV) irradiation could increase the health-promoting compounds in fruit but the effects of UV irradiation on the reduction of the polycyclic aromatic hydrocarbon (PAH) content in mulberries remain less known. Black mulberry fruit were exposed to two UV illumination dosages (3.5 and 7 kJ m-2 ) and were stored for 4, 8, and 12 days. Mulberries treated in this way displayed higher antioxidant enzyme activity and phenolic compound content in comparison with a control condition. The transcription factors (TFs) MdoMYB121, MdoMYB155, MdbZIP2, and MdbZIP48 were strongly expressed in two UV illumination dosages (about 45-95% higher than the control). The fluorine (Flu) and naphthalene (Nap) content in treated fruit decreased by 21-85% in comparison with the control condition. The findings of this study indicate that UV irradiation can be considered as a promising technique to remove some PAHs in black mulberries, to increase their health-promoting potential, and indirectly to improve their aesthetic quality due to the resulting desirable color parameters. © 2023 Society of Chemical Industry.