Department of Food Science and Technology, Bu-Ali Sina University, Hamedan, Iran.
Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran.
Sci Rep. 2022 Sep 13;12(1):15392. doi: 10.1038/s41598-022-19826-w.
Ultrasound (sonication) treatment can be used directly for dehydration or pre-treatment before the osmotic dehydration (OD) procedure of fruit or vegetable particles. The combination of this technique with the OD technique can further improve the dehydration process efficiencies by increasing the mass transfer rates and enhancing final product quality. In this study, apple slices were osmotically dehydrated in different hypertonic sucrose solutions and assisted with or without ultrasound. Sucrose concentrations (in three levels of 30, 40, and 50° Brix), sonication power (in three levels of 0, 75, and 150 W), and treatment time (in six time intervals: 10, 20, 30, 40, 50, and 60 min) were the factors investigated concerning weight reduction, soluble solids gain, water loss and rehydration. Also, mass transfer kinetics were modelled according to Page, Newton, Midilli, Logarithmic, Verma, and Two terms equations. Increased sucrose solution concentration resulted in higher weight reduction, soluble solids gain and water loss. Also, increased sonication power levels resulted in higher weight reduction, soluble solids gain and water loss. The average rehydration ratio of apple slices decreased from 237.7 to 177.5%, by increasing osmotic solution concentration from 30 to 50%. The Page equation showed the best fitting for water loss data. The effective moisture diffusivity (D) of apple slices during OD calculated using Fick's second law applied to a slab geometry was found to be in the range of 1.48 × 10 and 4.62 × 10 ms for water loss.
超声（声处理）处理可直接用于水果或蔬菜颗粒的脱水或渗透脱水（OD）前预处理。将该技术与 OD 技术结合使用可以通过提高传质速率和提高最终产品质量来进一步提高脱水过程效率。在这项研究中，苹果片在不同的高渗蔗糖溶液中进行渗透脱水，并在有或没有超声的情况下进行辅助。蔗糖浓度（三个水平：30、40 和 50°Brix）、超声功率（三个水平：0、75 和 150 W）和处理时间（六个时间间隔：10、20、30、40、50 和 60 分钟）是研究减轻重量、可溶性固形物增加、水分损失和再水化的因素。此外，还根据 Page、Newton、Midilli、对数、Verma 和两项方程对质量传递动力学进行了建模。增加蔗糖溶液浓度会导致更高的减重、可溶性固形物增加和水分损失。此外，增加超声功率水平会导致更高的减重、可溶性固形物增加和水分损失。通过将渗透溶液浓度从 30 增加到 50%，苹果片的平均复水比从 237.7%降低到 177.5%。Page 方程最适合于水分损失数据的拟合。使用 Fick 第二定律应用于平板几何形状计算的苹果片有效水分扩散系数（D）在水分损失时的范围为 1.48×10 和 4.62×10 ms。
