Research on energy metabolism, lignification and veil opening in postharvest white mushroom (<i>Agaricus bisporus</i>) under high O₂/CO₂ controlled atmospheres (HOC-CA)

White mushroom is an abundant nutritional but perishable product; veil opening and stipe lignification are two of the obvious characte-ristics of senescence. In order to study the relationship between the energy charge, veil opening and lignification of the white mushroom, high O2/CO2 controlled atmospheres (HOC-CA) were utilized at 2±1 °C. The treatments comprised the following 100% O2, 80% O2 + 20% CO2, 60% O2 + 40% CO2, 40% O2 + 60% CO2 respectively, with air as the control. In this study, sensorial and physiological qualities, adenosine triphosphate (ATP) content, energy charge level, lignin content, phenylalanine ammonia-lyase (PAL), cinnamyl alcohol dehydrogenase (CAD) and peroxidase (POD) activity were studied. The optimal condition 80% O2 + 20% CO2 treatment inhibited both respiration rate and veil opening of the mushroom; suppressed PAL, POD and CAD activity. It also retarded the reduction of ATP level, energy charge level, and growth of lignin content. Exogenous ATP had an effect on inhibiting veil opening and lignification. These results indicated that there was a negative correlation between the ATP content, cap opening and stipe lignification. Appropriate HOC-CA maintained high energy, preserved the white mushroom well and extended the storage time to 24 days