Study On The Application Of Ionized Air In The Fresh-Keeping Of Cucumber

This paper reviewed the technological development of the storage of cucumber (Cucumis sativus L.), and summarized the research results in experiments on application of ionized air to preservation of fruit and vegetables. In the 10-day research, Effect of using ozone or anion every day for cucumber storage in 19-25℃were compared. Total sensory quality, respiration, water, chlorophyll, weight loss, soluble solids, titratable acid and other physiological indicators of cucumber were studied when cucumbers were storaged at room temperature. Cucumbers were individual exposured to ozone or anion gas every other day at 12℃for 28 days. Quality-related attributes of cold-storage cucumbers through qualitative and quantitative evaluation including water loss, respiration rate, polyphenoloxidase (PPO), peroxidase (POD), MDA, firmness, brittleness, springness and scanning electron microscopy of cucumber skin during storage were examined. The main results were as follows:1. Effect of ozone gas in the preservation of cucumberWhile under normal temperature condition, the best effect of preservation was showed in the treatment of ozone gas to a 1.112mg/L of concentration every day. Such ozone treatment was considered a potential to extend storage life, inhibited the respiration rates, water loss and soluble solids decomposition of cucumber. High concentrations of ozone (1.668mg/L) damaged cucumber epidermis chlorophyll, resulted in the outflow of skin juice, accelerated the trend of weight loss increase and reducing suger significantly decrease. So, high concentration ozone treatment was not a good choice for cucumber preservation.2. Effect of anion gas in the preservation of cucumberCucumbers were preserved in room temperature storaged for 10 days with different concentrations of anion daily treatments. Results showed that 3-5 million units anion discharged for 2 minutes every day was the most favorable treatment to maintain the quality of cucumber. There was no mildew and corruption phenomenon found in the whole storge as results of anion treatment. Anion treatment significantly inhibited the respiration rate of cucumber, the decline of water content and soluable solids loss, and also maintained good skin color. High concentration of anion inhibited the decrease of titratable acid in cucumber, but got no significant impaction in reducing sugar.3. Effect of ionized air and low temperature in physiological charateristics of cucumberCucumbers were respectively exposed to appropriate concentrations of ionized air including ozone and anion every two days at the optimum storage temperature of 12℃. Effects of ozone and anion treatments in the chilling storage of cucumber were studied. The results showed that anion treatment maintained the fresh best, and cucumbers after 28-days storage still got the crispy texture and tasted delicious. Comparing with ozone and blank treatment, anion treatment significantly inhibited the trend of aging in cucumbers, the respiration rates, weight loss and the changes of MDA content. As it appeared to keep the integrity of skin, juices drain of cucumber was prevented. And also, the inhibition of POD and PPO activities in anion treatment were more efficient than ozone treatment.4. Effect of ionized air and low temperature in micro-texture parameters of cucumber skinCucumbers were treated seperately by appropriate concentrations of ozone and anion in the chilling storage of 12℃. Through the analysis of some texture parameters of cucumbers, it showed that anion could maintain the hardness,brittleness and springiness of the whole cucumber, while ozone treatment appeared unfavorable. Waxy substance seemed decreased obviously in ozone-treated cucumber skin comparing with anion-treated cucumber skin by scanning electron microscopy.