Effect Of Air Discharge Combiniing With Coating On Lotus Root Preservation

Lotus root as a kind of medicine edible aquatic vegetables,the market demand is growing day by day,but browning and mildew easily happened during the process of storage,this phenomenon cause loses value of lotus root in market,some sort of preservation techniques are required.In order to develop an effective and safe preservation method for lotus root,in this study we effectively use air discharge preservation technique in combination with chitosan and carrageenan composite membrane to evaluate the quality of lotus root during storage process.The main findings of this study were as follows:1.Ozone was used on the basis of everyday,two days and three days interval.The result of everyday use of ozone caused in quality decline with promoted browning ratio of lotus root.The two interval ozone treatment for 25 minutes with concentration of 2.5 ppm showed an effectively inhibition of lotus root mildew as well as improved the quality of lotus root during storage period.While every three days interval ozone treatment on lotus root did not significantly affect it quality.2.Negative ions was used on the basis of everyday,two days and three days interval to study its effect on quality of lotus root during storage.The results revealed that the every two days treatment with negative ions for 15 minutes significantly inhibited browning,effectively reduced the rate of weight lose and suppressed the respiration of lotus root,but the microbial growth rate was still higher.3.The preservative results of use of ozone in combination with negative ions were not satisfactory as compared to individual treatments of ozone and negative ions for everyday interval treatment.Every two days interval treatment for 25 minutes with ozone and 15 minutes negative in combination significantly reduce the microbial growth rate and inhibit the browning,but epidermis of lotus root was relatively dry during storage.4.Different concentrations of chitosan were studied for their impacts on the rate of weightlessness,respiratory intensity and browning index changes of lotus root as well as also studied the chitosan composite membrane for its impact on the quality of lotus root.The quality of lotus root was found best during storage when the concentration of chitosan was 2%,with combination of carrageenan in an addition amount of 0.2%.5.Studied the impact of air discharge in combined with chitosan composite membrane on the quality of lotus root.The effect showed that: after use of chitosan composite membrane treatment(the concentration of chitosan was 2%,with combination of carrageenan in an addition amount of 0.2%)used air discharge(every two days interval treatment for 25 minutes with ozone and 15 minutes negative in combination)treatment on lotus root,significantly reduced the rate of weigh lose of lotus root,improved the lotus root skin moisture,reduced the occurrence of browning and mildew as well as effectively prolong the shelf life of lotus root to 17 days.