Preservation mechanism and flavor variation of postharvest button mushroom (Agaricus Bisporus) coated compounds of protocatechuic acid-CaCl2-NaCl-pullulan

To clarify preservation mechanism and flavor variation of postharvest button mushroom (Agaricus Bisporus) coated compounds of protocatechuic acid-CaCl2-NaCl-pullulan, the protocatechuic acid (118 mg/L)-CaCl2 (0.83%)-NaCl (0.55%)-pullulan (0.30%) composite preservative (CP) at the spray rate of 13:1 was used to coating on button mushroom and storage at 4 ± 1 °C. Compared to the negative control (NC) group, the respiration rate, browning degree, malondialdehyde (MDA) content, polyphenol oxidase (PPO), and total phenolic content of CP treatment decreased 26%, 27%, 25%, 26% and 37% respectively after 12days. On the contrary, the peroxidase (POD), catalase (CAT), phenylalanine ammonia-lyase (PAL) and total superoxide dismutase (T-SOD) of CP treatment increased 57%, 40%, 39% and 30% respectively. Further, button mushroom coated with CP maintained a higher content of soluble protein and nucleic acid, but lower content of free amino acid (FAA) than NC group. Characteristic flavor substance of button mushroom coated by CP, 3-octanone was higher than that in the NC group, but lower alkanes. Moreover, there was no significant difference in 3-octanone between the CP and fresh button mushroom. Hence, the CP treatment had improved postharvest button mushroom texture and flavors, and storage at 4 ± 1 °C, its shelf life is prolonged to 12 days after coated compounds of protocatechuic acid (118 mg/L)-CaCl2 (0.83%)-NaCl (0.55%)-pullulan (0.30%).