Ricce Cinthia, Rojas Meliza Lindsay, Miano Alberto Claudio, Siche Raul, Augusto Pedro Esteves Duarte
Department of Agri-food Industry, Food and Nutrition (LAN), Luiz de Queiroz College of Agriculture (ESALQ), University of São Paulo (USP), Piracicaba, SP, Brazil; Escuela de Ingeniería Agroindustrial, Facultad de Ciencias Agropecuarias, Universidad Nacional de Trujillo, Trujillo, LL, Perú.
Department of Agri-food Industry, Food and Nutrition (LAN), Luiz de Queiroz College of Agriculture (ESALQ), University of São Paulo (USP), Piracicaba, SP, Brazil.
Food Res Int. 2016 Nov;89(Pt 1):701-708. doi: 10.1016/j.foodres.2016.09.030. Epub 2016 Sep 28.
The present work aimed to describe the mechanisms involved in the enhancement of the drying and rehydration process of carrot slices caused by the pre-treatment using the ultrasound technology. For that, carrot slices of 4mm of thickness were pre-treated for 30 and 60min using an ultrasonic bath (41W/L; 25kHz). The convective drying process was performed at 40 and 60°C with 2.0m/s of air velocity, while the rehydration process was performed at 25°C. The Henderson & Pabis model was used to describe the drying kinetics and the Peleg model to describe the rehydration process of the carrots slices. As a result, the drying and rehydration kinetics were described, at the different conditions of process, correlating the results with the main effects that the ultrasound cause as a pre-treatment (cell bloating and micro-channels) and the air-drying temperature. Depending on the length of the pre-treatment, the effects caused by the ultrasound in the following processes were different. In addition, it was corroborated that when the drying temperature is increased, less evidenced is the ultrasound effect. The ultrasound, when is applied for long times, enhanced the drying and further rehydration rate at low temperatures, due to the tissue damage. Moreover, vacuum-packed samples were pre-treated with ultrasound in order to exclude the water gain and to evaluate only the micro-channels formation effect. It was concluded that the ultrasound pre-treatment enhances the drying and rehydration processes; however, future optimization studies are recommended.
本研究旨在描述超声技术预处理对胡萝卜片干燥和复水过程增强作用的相关机制。为此，将厚度为4mm的胡萝卜片置于超声浴（41W/L；25kHz）中分别预处理30分钟和60分钟。对流干燥过程在40℃和60℃、风速2.0m/s的条件下进行，而复水过程在25℃下进行。采用亨德森和帕比斯模型描述干燥动力学，用佩莱格模型描述胡萝卜片的复水过程。结果表明，在不同工艺条件下描述了干燥和复水动力学，将结果与超声预处理产生的主要影响（细胞膨胀和微通道）以及热风干燥温度相关联。根据预处理时间的长短，超声在后续过程中产生的影响有所不同。此外，证实了干燥温度升高时，超声效果不太明显。长时间施加超声，由于组织损伤，在低温下提高了干燥和进一步的复水速率。此外，对真空包装的样品进行超声预处理，以排除水分增加的影响，仅评估微通道形成的效果。得出的结论是，超声预处理增强了干燥和复水过程；然而，建议未来进行优化研究。
