Physical Preservation Technology Research And Application Of Typical Organic Vegetables

The use of synthetic, pesticide, fertilizer, growth regulators and GM varieties are prohibited in the cultivation of organic vegetables. Organic vegetable fresh preservation can only be done by controlling the temperature and the humidity and the packing material and no chemical was allowed to use as preservatives. Organic vegetables are considered to be the safest food among the pollution-free vegetables and green vegetables. There is an acute need for food preservation techniques.9typical leaf vegetable,a fruit vegetable and one kind of cauliflower which are widely organically grown in Yangtze River delta were chosen as the test subjects:swamp morning glory、 delectamentum acetabula、sweet potato leaves、Hangzhou cabbage、gynura Bicolor、amaranthi、 basella、flowering chinese cabbage、lactuca、organic peper and broccoli. The presentation of current development of preservation technology at home and abroad was made. Vacuum cooling physical preservation experiments of typical vegetables under high temperature with non-replenishment of water had been made. The study on organic horn pepper with PVC cling film packaging and organic broccoli with different packaging and handling had also carried out to find the impact of their quality.Results showed that:(1) The respective temperature difference of vegetables under high temperature with non-replenishment of water are as follows:swamp morning glory≤19.4±0.5℃;delectamentum acetabula<19.9±0.5℃;sweet potato leaves<16.2±0.5℃; Hangzhou cabbage<21.0±0.5℃; gynura Bicolor≤21±0.5℃; amaranthi≤21.5±0.5℃; basella<30.0±0.5℃; flowering chinese cabbage≤35.0±0.5℃.(2) Stored at9-11℃,rot rate of organic peper can be effectively controlled with PVC cling film packaging.(3) After pre-cooled with cold air and the vacuum respectively, organicum lctuca was kept in cold storage with temperature at0-4℃and relative humidity at90%～95%. Results indicate that the vacuum pre-cooling treatment had better effect than the cold air by measuring its senses, filtration rate, chlorophyll and ascorbic acid content.(4) With the rapid vacuum cooling to8℃,the time between harvesting to pre-cooling of organic Hangzhou cabbage can be shorten and it can be stored for long time to prevent from shrivelling up with non-replenishment of water. It was then kept in cold storage with temperature at0～4℃and relative humidity at90%～95%can stay fresh for27days. Considering the nutritional value with more vitamin C (ascorbic acid),it is recommended that the storage time should be less than17days.(5) After vacuum cooling, then using p-plus (imported high-density microporous film bag) or insulation foam box for packaging the organic broccoli,placed them into±0.5℃environment,or using insulation foam box for packaging the organic broccoli,then placed them into9～11℃environment has a significant effect on delaying the rise of water loss rate, soluble solids,chlorophyll,ascorbic acid decline.