Effect of light on quality of preharvest and postharvest edible mushrooms and its action mechanism: A review

Edible mushrooms are favored by people for their rich nutrition, medicinal value and unique flavor. However, the improvement of the yield and quality of preharvest edible mushrooms and preservation of postharvest edible mushrooms are one of the major challenges in the development of the industry. Light exerts direct beneficial effects in edible mushrooms and has become a promising new field for improving their quality. This review described four common light treatment techniques used on preharvest and postharvest edible mushrooms, namely visible light (VL), γ-irradiation, ultraviolet (UV) and pulsed light (PL). General effects, mechanisms and regulations around the use of light in preharvest and postharvest edible mushrooms was discussed. Different wavelengths of VL (especially blue light) mainly focus on improving the growth characteristics and nutritional value of preharvest edible mushrooms by regulating physiological metabolism, and their effects on flavor are worth exploring. For postharvest edible mushrooms, γ-irradiation, UV, PL and VL can improve the quality and prolong their shelf life by regulating the physiological and energy metabolism, inducing photochemical reactions, and inhibiting microbial activity. The effects of γ-irradiation on their nutritional and flavor quality are controversial. UV has a good effect on improving their nutrients and bioactive components. PL and VL are effective in improving their flavor quality. The combination of different light treatments and the combination of light and other preservation techniques can be the focus of the following research. Next, it is necessary to find out the specific photoreceptors and light response networks corresponding to different light sources by modern analysis and multi-omics technology combined with the research theories and means of stoichiometry and bioinformatics, so as to fully reveal the regulatory pathways of light on the physiology and energy metabolism, chemical reaction and light microbial degradation of mushrooms.