Food Technology Department, Federal Institute of Education, Science and Technology of Paraná, Colombo, Brazil.
Environmental and Food Interdisciplinary Studies Laboratory, Latin American Institute of Life and Nature Sciences (ILACVN), Federal University of Latin American Integration (UNILA), Foz do Iguaçú, Brazil.
Plant Foods Hum Nutr. 2023 Dec;78(4):704-709. doi: 10.1007/s11130-023-01110-5. Epub 2023 Oct 7.
The aim of this work was to study the effect of blanching and ultrasound pretreatments on drying and quality characteristics of apple peel. Blanching was conducted in boiling water, ultrasound in a water bath, and drying in a batch tray dryer. The product obtained was ground into a flour, and assessed for color, water activity, proximate composition, sugars, and bioactive compounds. Results showed that effective moisture diffusivity increases with a decrease in product moisture content, being such dependence well described by a second order polynomial model. Average drying rate was higher and product moisture content was lower for blanched and sonicated flour, especially for the former. Such result suggests that blanching and ultrasound enhance water removal during drying of apple peel. Physical properties were significantly affected by pretreatments, being more intense red color and lower water activity obtained for sonicated flour. Nutritional and bioactive properties were also significantly affected by pretreatments, being lower sugar, higher protein, fiber, catechin and epicatechin content observed for blanched flour. Summarizing, blanching and ultrasound pretreatments improve drying of apple peel, both regarding process efficiency and product quality.
本工作旨在研究烫漂和超声预处理对苹果皮干燥和品质特性的影响。烫漂在沸水中进行，超声在水浴中进行，干燥在批式托盘干燥器中进行。所得产物磨成粉末，评估其颜色、水分活度、近似成分、糖和生物活性化合物。结果表明，有效水分扩散系数随产品水分含量的降低而增加，这种依赖性可以很好地用二阶多项式模型来描述。与未经处理的苹果皮粉相比，烫漂和超声处理的苹果皮粉的平均干燥速率更高，产品水分含量更低，尤其是前者。这一结果表明，烫漂和超声处理可在苹果皮干燥过程中增强水分去除。物理性质受到预处理的显著影响，超声处理的苹果皮粉颜色更红，水分活度更低。营养和生物活性特性也受到预处理的显著影响，烫漂处理的苹果皮粉的糖、蛋白质、纤维、儿茶素和表儿茶素含量更高。综上所述，烫漂和超声预处理可改善苹果皮的干燥过程，无论是在工艺效率还是产品质量方面。
