Method for non-sulfite color protection of Pleurotus eryngiu during drying process

In order to solve the problem of browning during the process of Pleurotus eryngiu drying, seven kinds of color protectors were adopted to treat Pleurotus eryngiu, which were sodium pyrosulfite, EDTA-2Na, zinc acetate, sodium chloride, calcium chloride, citric acid and vitamin C. Then the mushroom was dried by different methods. The results show that the method of drying at initial temperature of 35℃, and increasing temperature at a rate of 5℃/h to 60℃, keeping the temperature at 60℃ for one hour, then decreasing the temperature to 50℃, is favorable for the dehydration and color protection of Pleurotus eryngiu. Among the non-sulfite color protectors, citric acid and vitamin C have the best effects of color protection, the next are EDTA-2Na and sodium chloride. The effects of color protection of the above four protectors were better than that of sodium pyrosulfite. The optimum combination of color protectors was 0.2% citric acid, 0.3% vitamin C, 1% sodium chloride and 0.15% EDTA-2Na, and the effect of color protection of it was better than that of the single kind of color protectors.