نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Drying is an important method to preserve foodstuffs and agricultural products. Intermittent drying techniques are new methods that have been developed recently in which the heating source is turned off at certain cycles. In this research, the effect of the intermittent drying method and its cycles on the drying time, effective moisture diffusivity, and qualitative characteristics of carrot slices was studied. Three different cycles were investigated. In the first cycle, the infrared source was turned on for 5 min and then turned off for 10 min (HA IR (I:5 10)). In the second cycle, the infrared source was turned on for 10 min and then turned off for 10 min (HA IR (I:10 10)). In the last cycle, the infrared source was turned on for 10 min and then turned off for 5 min (HA IR (I:10 5)). To compare the results, the drying process was also studied using continuous hot air–infrared drying (HA IR), hot air drying (HA) and the IR drying. The results showed that the drying time of carrot slices using HA, IR, HA IR, HA IR (I:5 10), HA IR (I:10 5), and HA IR (I:10 10) drying methods was 257, 242, 166, 227, 219, and 203 min, respectively. The effective moisture diffusivity of carrot slices was in the range of 6.227×10⁻¹¹ to 9.226×10⁻¹¹ m²/s. The lowest values of true density and shrinkage were observed in the samples dried by the intermittent treatment HA IR (I:10 10), with values of 1.043 g/cm³ and 83.94%, respectively. The color change of the peripheral and central parts of the samples dried by HA IR (I:10 10) was the lowest, with values of 7.47 and 6.43, respectively. Intermittent hot air–infrared drying, HA IR (I:10 10), helped preserve the quality of the dried samples.
کلیدواژهها English