Université de Tunis El Manar, Unité de recherche «Chimie des matériaux et de l'Environnement», Institut Supérieur des Sciences Biologiques Appliquées de Tunis (ISSBAT), 9, rue Zouhair Essafi, Tunis 1006, Tunisia.
Université de Tunis El Manar, Unité de recherche «Chimie des matériaux et de l'Environnement», Institut Supérieur des Sciences Biologiques Appliquées de Tunis (ISSBAT), 9, rue Zouhair Essafi, Tunis 1006, Tunisia.
Ultrason Sonochem. 2017 May;36:286-300. doi: 10.1016/j.ultsonch.2016.12.007. Epub 2016 Dec 7.
The work was planned to produce dietetic dehydrated strawberries with application of ultrasound osmotic dehydration (UOD) as pretreatment. A Box-Behnken design (BBD) were employed to characterize the UOD strawberry process, optimize and investigate the effect of independent variables like ultrasound time (10, 20 and 30min), concentration of osmotic solution (distilled water, 32.5 and 65 °Brix) and temperature (20, 30 and 40°C) on the water loss (WL), solid gain (SG) and weight reduction (WR). The same BBD were used to estimate the main effects of OD without ultrasound treatment. A multi-criteria optimization based on maximal possible values of WL and WR and minimal value of SG was achieved. This was 20.5min of ultrasound time, 47.5 °Brix osmotic solution concentration and 31°C medium temperature. The effects of UOD carried out under the optimized operating conditions on kinetics of convective air drying of strawberry at 40, 50 and 60°C, and velocity of 1m/s, using the phenomenological model of Coupled Washing/Diffusion (CWD). Starting accessibility, moisture effective diffusivity D value and activation energy (Ea) were calculated from similar-Fick's law and analogous Arrhenius equation, respectively with and without shrinkage correction. Color difference, Chroma and hue angle of fresh and UOD-air dried strawberries were evaluated. Quality attributes were estimated through the assessment of the phenolic content, antioxidant activity, rehydration capacity, and X-ray powder diffraction characteristics.
本工作旨在通过超声渗透脱水（UOD）预处理来生产脱水草莓。采用 Box-Behnken 设计（BBD）来表征 UOD 草莓工艺，优化并研究了独立变量如超声时间（10、20 和 30min）、渗透溶液浓度（蒸馏水、32.5 和 65°Brix）和温度（20、30 和 40°C）对水分损失（WL）、固形物增益（SG）和减重（WR）的影响。同样的 BBD 用于估计没有超声处理的 OD 的主要影响。基于 WL 和 WR 的最大值和 SG 的最小值进行了多准则优化。这是 20.5min 的超声时间、47.5°Brix 的渗透溶液浓度和 31°C 的中等温度。在优化的操作条件下进行的 UOD 对草莓在 40、50 和 60°C 下以 1m/s 的速度进行的对流空气干燥动力学的影响，使用耦合洗涤/扩散（CWD）的经验模型。根据相似的 Fick 定律和类似的 Arrhenius 方程，分别在有和没有收缩修正的情况下，从起始可及性、水分有效扩散系数 D 值和活化能（Ea）进行计算。评估了新鲜和 UOD-空气干燥草莓的色差、Chroma 和色调角。通过评估酚类含量、抗氧化活性、复水能力和 X 射线粉末衍射特性来估计质量属性。
