Rudy Stanisław, Dziki Dariusz, Biernacka Beata, Polak Renata, Krzykowski Andrzej, Krajewska Anna, Stanisławczyk Renata, Rudy Mariusz, Żurek Jagoda, Rudzki Grzegorz
Department of Thermal Technology and Food Process Engineering, University of Life Sciences in Lublin, Głęboka St. 31, 20-612 Lublin, Poland.
Department of Agricultural Processing and Commodity Science, Institute of Food and Nutrition Technology, College of Natural Sciences, University of Rzeszow, Zelwerowicza St. 4, 35-601 Rzeszów, Poland.
Foods. 2024 Aug 18;13(16):2585. doi: 10.3390/foods13162585.
The objective of this study was to evaluate the impact of various drying methods: freeze drying, vacuum drying, convection drying, and convection-microwave drying at microwave powers of 50 W and 100 W, along with process temperatures (40 °C, 60 °C, and 80 °C), on the drying kinetics, selected physicochemical properties of dried celery stems, and their grindability. The Page model was employed to mathematically describe the drying kinetics across the entire measurement range. Convection-microwave drying significantly reduced the drying time compared to the other methods. The longest drying duration was observed with freeze drying at 40 °C. The product obtained through freeze drying at 40 °C exhibited the least alteration in color coordinates, the highest antioxidant capacity, and the greatest retention of chlorophylls and total carotenoids. At a specific temperature, the quality of the product obtained from vacuum drying was slightly lower compared to that from freeze drying. The most substantial changes in the physicochemical properties of the dried product were observed with convection-microwave drying at a microwave power of 100 W. The drying method selected had a significant impact on the energy consumption of grinding, average particle size, and the grinding energy index of the dried celery stems; these parameters worsened as the drying temperature increased. The product with the best quality characteristics and disintegration parameters was achieved using freeze drying at 40 °C.
冷冻干燥、真空干燥、对流干燥以及在50 W和100 W微波功率下的对流-微波干燥，同时考察工艺温度（40℃、60℃和80℃）对干燥动力学、干燥芹菜茎的选定理化性质及其可磨性的影响。采用Page模型对整个测量范围内的干燥动力学进行数学描述。与其他方法相比，对流-微波干燥显著缩短了干燥时间。在40℃下进行冷冻干燥时观察到最长的干燥持续时间。在40℃下通过冷冻干燥获得的产品在颜色坐标上的变化最小，具有最高的抗氧化能力，并且叶绿素和总类胡萝卜素的保留率最高。在特定温度下，真空干燥获得的产品质量与冷冻干燥获得的产品相比略低。在100 W微波功率下进行对流-微波干燥时，观察到干燥产品的理化性质发生了最显著的变化。所选的干燥方法对干燥芹菜茎的研磨能耗、平均粒径和研磨能量指数有显著影响；随着干燥温度的升高，这些参数变差。使用40℃下的冷冻干燥获得了具有最佳质量特性和崩解参数的产品。
