Changes in the physicochemical composition of Auricularia auricula during growth stages and control of endogenous formaldehyde

•The critical period of formaldehyde generation was identified and controlled.•RAA had the highest comprehensive score and high endogenous formaldehyde.•Total sugar and flavonoid are negatively correlated with endogenous formaldehyde.•GGT and C-S lyase together promote endogenous formaldehyde production.•Cys and Glu inhibited the production of endogenous formaldehyde.