Abstract:
Drying is a widely recognized process that reduces the need for storage and shipping weight, keeps free water out of the product, and prolongs its shelf life. An infrared dryer was designed to dry apples under different drying conditions. Apple slices of 6-, 4-, and 2-mm thicknesses were dried at intensities 0.130, 0.225, and 0.341 W/cm2 and airflow 1.0, 0.5, and 1.5 m/s. The dehydrating period was prolonged with higher airflow and shortened with higher infrared intensity (IR). The shortest dehydrating period was verified by 190 min at 0.341 W/cm2, 0.5 m/s under 2 mm thickness. Increasing the sample thickness from 2 to 4 mm and then to 6 mm resulted in an 84% and 192% increase in drying time, respectively. Dehydrated apples had water activity values ranging from 0.30 to 0.40. The shrinkage ratio increased with an increase in infrared radiation intensity. However, it decreased with an increase in air velocity, while the rehydration ratio decreased with an increase in radiation intensity and increased with an increase in air velocity. Regarding total color change, apple slice thickness was a major factor. The effective diffusivities varied between 2.6 and 9.0 𝗑10-10 m2/s under different drying conditions. The dehydrating curves of apples were best described by the model developed by Midilli et al.
摘要:
干燥是一种广泛认可的过程,可减少存储和运输重量的需求,保持产品中的自由水,并延长其保质期。设计了一种红外干燥机,用于在不同干燥条件下干燥苹果。6-的苹果片,4-,和2mm厚度在强度0.130、0.225和0.341W/cm2和气流1.0、0.5和1.5m/s下干燥。气流增加,脱水时间延长,红外强度(IR)增加,脱水时间缩短。在2mm厚度下,在0.341W/cm2、0.5m/s下,通过190分钟验证最短脱水时间。将样品厚度从2毫米增加到4毫米,然后增加到6毫米,导致干燥时间增加84%和192%,分别。脱水苹果的水分活度值在0.30至0.40之间。收缩率随红外辐射强度的增加而增加。然而,它随着空气速度的增加而减少,而再水化率随着辐射强度的增加而降低,随着空气流速的增加而增加。关于总颜色变化,苹果切片厚度是一个主要因素。在不同的干燥条件下,有效扩散率在2.6和9.0之间变化?10-10m2/s。苹果的脱水曲线最好用米迪利等人开发的模型描述。