红外干燥方式对紫甘蓝干燥特性的影响

Effects of Infrared Drying Technology on Drying Characteristics of Purple Cabbage

采用干燥方式可延长紫甘蓝货架期,红外干燥具有较强的穿透能力,适合叶片型蔬菜的干燥。但是红外干燥时,干燥参数设置不合理,反而会带来一些副作用,对干制品品质产生一定的影响。因此,研究了不同干燥温度(40℃、50℃、60℃、70℃和80℃)、红外辐射距离(5 cm、11 cm和16 cm),红外辐射功率(225 W、450 W、675 W、900 W和1125 W)以及风速(10 m/s、20 m/s和26 m/s)对紫甘蓝干燥速率、复水率和褐变程度的影响。干燥温度越高,紫甘蓝干燥速率越快。不同红外辐射距离、辐射功率和风速对样品干燥速率影响不太明显。另外,干燥温度和辐射功率对样品复水率影响较大,随着温度升高,复水率增加;当辐射功率为675 W时,复水率最大。鉴于温度和能耗的关系,选择60℃作为干燥温度、11 cm为红外辐射距离、675 W作为红外辐射功率以及20 m/s为干燥风速,该研究为红外干燥技术的广泛应用提供了借鉴标准。

The shelf life of purple cabbage could be prolonged by using drying technology. The infrared drying technology had a stronger penetrating capacity, which was suitable for drying of leaf vegetables. Effects of different drying temperature（40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃）, infrared radiation distance（5 cm, 11 cm, 16 cm）, infrared radiation power（225 W, 450 W, 675 W, 900 W, 1125 W） and air speed（10 m/s, 20 m/s, 26 m/s） on the drying rate, rehydration rate and browning degree of purple cabbage were investigated in this study. Results showed that the drying rate of purple cabbage increased with the increase of temperature, and the radiation distance, infrared radiation power and air speed had little effects on the drying characteristics of purple cabbage. The rehydration rate of samples was greatly affected by drying temperature and infrared radiation power and increased with the increase of temperature, and the highest peak of rehydration rate appeared at 675 W. The drying conditions, based on temperature and energy consumption, were as follows： temperature, 60 oC, radiation distance, 11 cm, radiation power, 675 W, air speed, 20 m/s. This research provided reference for the widespread application of infrared drying technology.