Dehydration of green beans using ultrasound-assisted vacuum drying as a novel technique: drying kinetics and quality parameters

Abstract

The ultrasound‐assisted vacuum (USV) drying technique is a novel method and ultrasonic treatment under vacuum causes to accelerate the dehydration rate of food materials. This study compared the drying kinetics and some quality parameters for green beans subjected to USV, oven, and vacuum drying at 55, 65, and 75°C. The drying time was shortened by around 1 hr using USV at each temperature. Effective moisture diffusivity values was found between 2.00 × 10−10 − 4.81 × 10−10 m2 s−1 and it was increased compared with control treatment between 8.9% and 24.5%. USV treatment resulted phenolic compounds compared with unsonicated control. However, USV caused more color change than the control, oven and vacuum. Lower the total color difference values were obtained for samples dehydrated by vacuum dryer. USV had greater advantages compared with the control and it can potentially be applied to green beans and other vegetables for faster drying processing. Practical applications This study exhibit the usability of ultrasound‐assisted vacuum dehydration to increase the drying rate, to improve the energy efficiency of the drying process and to develop quality of the final products. The results indicated that ultrasound treatment could be used as an assistant technique to accelerate drying rate and improve product quality. Besides mathematical models and drying kinetic, this study presents useful information about the different dehydration process for green bean. It was expected that this study will great contribution to literature, food science and technology.

The effect of microwave and convective dryer with ultrasound pre‐treatment on drying and quality properties of walnut kernel

“…In other words, higher temperature led to larger mass transfer and resulted in lower drying time and reduction in specific energy consumption (Filippin, Filho, Fadel, & Mauro, ). The values of SEC are in agreement with the documented values of 1.197–1.357 kWh for oven drying, 1.107–1.500 kWh for vacuum drying, 1.731–1.961 kWh for US‐vacuum, and 1.571–1.665 kWh for the control applied for green beans (Tekin, Başlar, Karasu, & Kilic, ), 0.17 kWh for CON drying assisted by US of mango Tommy (Mendez‐Calderon, Ocampo‐Castano, & Orrego, ), 20.03 to 56.15 MJ/kg for air‐borne US on fluidized bed drying at different frequencies (20 and 30 kHz) and air temperature (40 to 60°C) of corn kernels (Abdoli et al, ).…”

Application of High-Power Ultrasound in the Food Industry

“…In addition to improving convection drying processes, studies have also been carried out on the application of ultrasound in vacuum drying [78,79] or in freezedrying [80,81] obtaining higher drying rates than the traditional process.…”

An Analysis of Waste Heat Recovery from Wastewater on Livestock and Agriculture Farms

“…The removal of water from a wide range of materials (fruit and vegetables, cereals) is dictated by many beneficial drying effects. First of all, there is a decrease in water activity and the release of chemical reactions, as well as the practical elimination of enzymatic reactions and the development of microorganisms, as a result of which the product is much more durable [39]. In addition, in most cases, the weight and volume of the materials dried are reduced, which facilitates and reduces packaging, transport and storage costs.…”