School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Dept. of Botany, Shah Abdul Latif University, Khairpur 66020, Sindh, Pakistan.
Ultrason Sonochem. 2020 Nov;68:105226. doi: 10.1016/j.ultsonch.2020.105226. Epub 2020 Jun 13.
The influence of ultrasonic frequency (20 kHz) and glucose pretreatments either alone or in combination on the drying of sweet potato slices (3 mm) using a hot-air dryer at 60 °C was tested to study the kinetics modeling, phytochemicals, antioxidant activities, and functional and textural changes of the final dried product. The results indicated that total phenolic content and total flavonoid content were significantly higher in glucose-pretreated samples while antioxidant activities were higher in ultrasound- and glucose-pretreated samples. For vitamin C, much degradation occurred in the glucose-pretreated samples when compared with the other pretreated samples apart from the control. Enzymatic browning made a minor contribution to the ultrasound/glucose-pretreated samples, while no significant differences were noted in the glucose-pretreated samples. A modified Henderson and Pabis (MHP) model, followed by the two-term and Hii models, fitted best among the 15 selected mathematical models. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed the presence of glucose, phenols, and flavonols in all samples. Microstructural analysis confirmed the hardness (N) in the final glucose-pretreated samples due to glucose layers and less cell damage.
研究了超声频率（20 kHz）和葡萄糖预处理（单独或组合）对 60°C 热空气干燥器中 3mm 厚红薯片干燥的影响，以研究动力学模型、植物化学物质、抗氧化活性以及最终干燥产品的功能和结构变化。结果表明，总酚含量和总黄酮含量在葡萄糖预处理样品中显著较高，而超声和葡萄糖预处理样品中的抗氧化活性较高。与其他预处理样品相比，葡萄糖预处理样品中的维生素 C 降解较多，而对照组则没有明显差异。与葡萄糖预处理样品相比，超声/葡萄糖预处理样品中的酶促褐变贡献较小。在 15 种选定的数学模型中，改进的亨德森和帕比斯（MHP）模型、双项和 Hii 模型拟合效果最好。傅里叶变换红外光谱（FTIR）分析表明，所有样品中均存在葡萄糖、酚类和类黄酮。微观结构分析证实，由于葡萄糖层和较少的细胞损伤，最终葡萄糖预处理样品的硬度（N）较高。
