摘要: 葉菜類採收後在25℃高溫時,呼吸率高,小白菜達103 mg CO2/kg.hr,韭菜達471.4 mg CO2/kg.hr;以不同預冷方法使降溫到5℃,水冷需5~6分鐘,強風壓差預冷需20~25分鐘,真空預冷需4-5分鐘;預冷後以塑膠袋包裝,貯藏於5℃可以保存良好品質,且可時藏約6天,若貯於20℃,貯藏壽命則仍短,品質則下降快。預冷葉菜之葉色、全糖含量,纖維含量顯示比不做預冷的品質保存效果好。 蔬菜採收後應盡量減少受傷,再做預冷處理,對品質及保鮮期會有好的效果;主菜適合以強風壓差預冷或真空預冷,不適以水冷。小白菜以三種預冷方法均可,視運輸距離及設備費用而定,近郊葉菜類,以水冷及強風壓差預冷較經濟。The respiratory rate of leafy vegetable were strong under high temperature (25℃). The rate was 103 mg CO2/kg.hr for Pak-choi, while 471.4 g CO2/kg.hr for leek. By using different cooling methods to cool down to 5℃, it needed 5-6 minutes by hydrocooling, 20-25 minutes by forced air cooling and 4-5 minutes by vacuum cooling. After precooling, the vegetables were packaged with plastic film and stored under 5℃. They could keep good quality for 6 days, but shorten the storage period and changed quality if they were stored in 20℃. In comparing non-precooling, the precooling treament could keep better qaulity, higher total sugar content and lower fiber content. Vegetables treated with precooling could keep good quality and prolong the storage period. Leek was suitable to use vacuum cooling and forced air cooling, but not suitable for hydrocooling. Pak-choi was suitable for the above three methods depended on transportation distance and the cost of feasility. Hydrocooling and forced air cooling were suitable for suburb leafy vegetables. |