中短波红外和热风干燥对番木瓜干燥特性及品质的比较

Drying Characteristics and Quality of Carica Papaya Linn under Med- and Short-wave Infrared Radiation and Hot Air Drying

摘要:

本文以干燥特性、色泽、复水性以及抗坏血酸保留率为评价指标，研究了不同干燥温度（60、70、80、90 ℃）下中短波红外辐射和热风干燥对番木瓜片品质的影响。结果表明：与热风干燥相比，相同温度条件下中短波红外干燥速率更快，所需干燥时间更短；随着干燥温度的升高，两种干燥方式下的水分有效扩散系数均呈升高趋势，番木瓜片中短波红外干燥和热风干燥水分有效扩散系数分别为0.58546×10-10~9.87313×10-10 m2/s、0.01179×10-10~4.88646×10-10 m2/s；番木瓜片中短波红外干燥的活化能32.13 kJ/mol低于热风干燥的活化能33.28 kJ/mol；此外，中短波红外干燥后番木瓜片的色泽和产品的复水性更好，而番木瓜片的中短波红外干燥抗坏血酸保留率低于热风干燥。综合考虑，试验范围内中短波红外干燥温度为70 ℃条件下所得产品的品质最好。

Abstract:

The effects of infrared and hot air drying at different temperatures (60, 70, 80, and 90 ℃) on the quality of Carica Papaya Linn (papaya) slices were discussed. Four indicators viz. drying properties, color, rehydration, and vitamin C retention were employed. The results showed that, at the same drying temperature, the speed of infrared drying was faster than that of hot air drying . The effective moisture diffusion coefficients (Deff) increased with increase in drying temperature for both drying methods. The Deff of infrared drying and hot air drying ranged from 0.58546×10-10~9.87313×10-10 m2/s and 0.01179×10-10~ 4.88646×10-10 m2/s, respectively. The activation energy was 32.13 kJ/mol and 33.28 kJ/mol for the infrared and hot air drying, respectively. The papaya slices dried by infrared showed better color and rehydration properties than those dried by hot air. However, the papaya slices dried by hot air had higher vitamin C retention. In summary, the best product was obtained with infrared drying at 70 ℃.