Investigation Of High Humidity Storage On Quality Maintenance Of Three Ftuits

Fruit are very beneficial to human health.They are not only rich in nutritive properties including vitamins and minerals.Some types of fruit also contain a variety of natural antioxidants such as anthocyanins and phenolic antioxidants which have strong ability to scavenge free radicals.Postharvest fruit and vegetables are susceptible to mass loss,wilting and quality of deterioration during cryogenic storage and transportation.Therefore,controlling the humidity in the fruit storage environment is the key to maintain the moisture content,freshness,appearance quality,nutrition quality and commodity value.This dissertation took "qingzhong" loquat,"huangjingaun" yellow peach,"xiahei"grape as experimental materials.The storage temperature of loquat is 2 ±0.5 ?,The storage temperature of yellow peach and grapeis is1±0.5?.In order to provide theoretical basis for the development and application of high humidity storage technology,the present study was designed to compare the quality of fruit after the storage of 45 d in the relative humidity of 70-75%and 90-95%,respectively.The results were as follows:1.The effect of different relative humidity(70-75%and 90-95%)on quality and antioxidant activity of the loquat fruit were investigated.The results indicated that higher relative humidity can effectively reduce the respiration intensity and weight loss rate of loquat fruit,reduce the degree of lignification,maintain the juice rate,keep the sugar-acid ratio,delay the decrease of Vc content,maintain cell membrane permeability,loquat fruit had a better quality under the high humidity storage conditions.Under high humidity storage condition,the concent of total phenolics and PAL of loquat fruit was higher,the activity of antioxidase was higher and the content of reactive oxygen species was lower,which indicated that high humidity storage of loquat fruit could maintain the balance of active oxygen metabolism of loquat fruit,thus delaying fruit aging.2.The effect of different relative humidity(70-75%and 90-95%)on quality and antioxidant activity of the yellow peach fruit were investigated.The results indicated that higher relative humidity can effectively reduce the respiration rate and weight loss rate of yellow peach fruit,maintain sugar-acid ratio and hardness,delay the decline in Vc content,maintain cell membrane permeability,indicating yellow peach fruit had a better quality under the high humidity storage conditions.Under high humidity storage condition,The concent of total phenolics and the activity of PAL were higher,the activity of antioxidase was higher and the content of reactive oxygen species was lower,which indicated that the fruit of the yellow peach under high humidity storage condition could maintain the balance of active oxygen metabolism of yellow peach fruit,thus delaying fruit aging.3.The effect of different relative humidity(70-75%and 90-95%)on quality and antioxidant activity of the grape fruit were investigated.The results indicated that the rot rate of grape fruit had increased under higher relative humidity storage conditions.However,high humidity storage can effectively reduce the grape grain rate and weight loss rate,maintain the sugar-acid ratio and hardness,delay the decline in Vc content,maintain cell membrane permeability.The concent of total phenolics and the activity of PAL were higher,the activity of antioxidase was higher and the content of reactive oxygen species was lower,which indicated that the grape fruit could maintain the balance of active oxygen metabolism of grape fruit,thus delaying fruit aging.