The Experimental Study Of Lentils Hot Air Drying Characteristic

Lentils are nutrient rich, taste fresh and delicious vegetable in summer and autumn. Because of its seasonal and short storage time, it will damage without further processing.This paper will take the single factor experiment as the foundation. The curve of the moisture content and drying rate curves are drawn out. And the sensory quality of dried products of lentils is considered. The paper discussed that different air velocity, air temperature and the segmentation effect on drying process of lentil in detail. Results showed that increasing air temperature and velocity could accelerate drying rates, shorten drying time and improve drying efficiency. But the higher hot air temperature is, the yellower the color of dried product is. The sooner hot air velocity is, the stronger the curly degree of dried product is. The smaller slitting width will increase the processing complexity. The more proper drying conditions were found to follow test. The second step, after single factor experiment, orthogonal designed experiment of three factors, three levels was adopted to optimize the drying processing. The drying rate and recovery ratio of water are used to be indexes to consider better drying parameters. The better drying parameters of lentil’s hot air dryig experiment are determined. Hot wind speed, hot wind temperature, and the slit width are 1.5 m/s,65℃,15 mm. Finally, the prediction regression equation is fitted with thin layer drying model. The exponential model and single diffusion model is not suitable for this test. Dry page equation fitting model has particularly good effects.