Önal Begüm, Adiletta Giuseppina, Di Matteo Marisa, Russo Paola, Ramos Inês N, Silva Cristina L M
Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, Italy.
Department of Chemical Engineering Materials Environment, Sapienza University of Rome, via Eudossiana, 18, 00184 Rome, Italy.
Foods. 2021 Apr 14;10(4):853. doi: 10.3390/foods10040853.
The objective of this research was to evaluate the effect of drying temperature and innovative pre-treatments (i.e., microwave and ultrasound) on "Rocha" pear drying behavior and quality characteristics, such as color, total phenolic content and antioxidant activity. Experiments were carried out with pear slabs subjected to microwaves (2450 MHz, 539 W, 4 min, microwave oven) and ultrasounds (35 kHz, 10 min, in an ultrasonic bath) as well as control samples. The drying process was conducted in a tray dryer at three different temperatures (50, 55 and 60 °C) and a fixed air velocity of 0.75 m/s. Microwave technology resulted in a higher quality deterioration in dried pear samples compared to those of controls and ultrasound pre-treated samples. The combined application of ultrasound pre-treatment and the higher drying temperature of 60 °C was characterized by the lowest color changes (ΔE = 3.86 ± 0.23) and higher preservation of nutritional parameters (total phenolic content, TPC = 345.60 ± 8.99; and antioxidant activity, EC = 8.80 ± 0.34). The drying characteristics of pear fruits were also analyzed by taking into account empirical models, with the Page model presenting the best prediction of the drying behavior. In conclusion, ultrasound application is a promising technology to obtain healthy/nutritious dried "Rocha" pear snacks as dietary sources for consumers.
本研究的目的是评估干燥温度和创新预处理方法（即微波和超声）对“罗查”梨干燥行为和品质特性（如颜色、总酚含量和抗氧化活性）的影响。对梨片进行了实验，实验对象包括经微波处理（2450兆赫，539瓦，4分钟，微波炉）、超声处理（35千赫，10分钟，超声浴）的梨片以及对照样品。干燥过程在托盘干燥器中进行，温度设置为三个不同水平（50、55和60°C），空气流速固定为0.75米/秒。与对照样品和超声预处理样品相比，微波技术导致干燥梨样品的品质劣化程度更高。超声预处理与60°C的较高干燥温度相结合的特点是颜色变化最小（ΔE = 3.86 ± 0.23），营养参数（总酚含量，TPC = 345.60 ± 8.99；抗氧化活性，EC = 8.80 ± 0.34）的保留率更高。还通过考虑经验模型分析了梨果实的干燥特性，其中Page模型对干燥行为的预测效果最佳。总之，应用超声技术是一种很有前景的方法，可为消费者获取健康/营养的干燥“罗查”梨零食作为膳食来源。
