绿甜椒真空冷冻干燥工艺研究

Vacuum Freeze-Drying of Green Sweet Peppers

以绿甜椒为加工对象,进行真空冷冻干燥工艺研究,重点探索烫漂、浸护液的处理方案和冻干工艺参数选择。结果表明:95℃烫漂70s能完全灭酶、防止褐变,并能提高冻干甜椒的复原率;烫漂后浸入20℃的5%(m/m)NaCl+4%(m/m)葡萄糖+0.4%(m/m)CaCl2的浸泡液中,浸泡20min,能有效提高冻干产品中叶绿素的保留率和复原率;冻干工艺参数为-20℃条件下速冻、冻干过程的真空压力30Pa、升华温度5℃条件下保持3h,解析温度40℃条件下保持1.5h,冻干甜椒的含水率低于5%(m/m),产品品质较好。

The purpose of this study was to investigate the main factors affecting of the vacuum freeze-drying of green sweet peppers such as blanching, soaking solution and freeze-drying parameters. The results indicated that blanching at 95 ℃ for 70 s could inactivate enzymes completely to prevent green sweet peppers from browning and improve the recovery rate. In addition, soaking treatment with 20℃ solution containing 5% NaCl, 4% glucose and 0.4% CaCh for 20 min could effectively improve the retention rate of chlorophyll and recovery rate of green sweet peppers after blanching. Moreover, the optimal freeze-drying parameters were fast freezing at -- 20 ℃ and 30 Pa, sublimation at 5 ℃ for 3 h and resolution at 40 ℃ for 1.5 h. Under these treatment conditions, the quality of freeze-dried sweet peppers was significantly improved.