A new household ultrasonic cleaning method for pyrethroids in cabbage

Individual and interactive effect of ultrasound pre-treatment on drying kinetics and biochemical qualities of food: A critical review

One of the earliest and most prevalent processing methods to increase the shelf-life of foods is drying. In recent years, there has been an increased demand to improve product quality while lowering processing times, expenses, and energy usage in the drying process. Pre-treatments are therefore effectively used before drying to enhance heat and mass transfer, increase drying efficiency, and lessen degradation of final product quality. When food is dried, changes are expected in its taste, color, texture, and physical, chemical, and microbial properties. This has led to the need for research and development into the creation of new and effective pre-treatment technologies including high-pressure processing, pulsed electric field, ultraviolet irradiation, and ultrasound. Sound waves that have a frequency >20 kHz, which is above the upper limit of the audible frequency range, are referred to as "ultrasound". Ultrasonication (US) is a non-thermal technology, that has mechanical, cavitational, and sponge effects on food materials. Ultrasound pre-treatment enhances the drying characteristics by producing microchannels in the food tissue, facilitating internal moisture diffusion in the finished product, and lowering the barrier to water migration. The goal of ultrasound pre-treatment is to save processing time, conserve energy, and enhance the quality, safety, and shelf-life of food products. This study presents a comprehensive overview of the fundamentals of ultrasound, its mechanism, and how the individual effects of ultrasonic pre-treatment and the interactive effects of ultrasound-assisted technologies affect the drying kinetics, bioactive components, color, textural, and sensory qualities of food. The difficulties that can arise when using ultrasound technology as a drying pretreatment approach, such as inadequate management of heat, the employment of ultrasound at a limited frequency, and the generation of free radicals, have also been explained.

Effect of ultrasound assisted cleaning on pesticide removal and quality characteristics of Vitis vinifera leaves

In this study, the pesticide (acetamiprid, deltamethrin, and pyridaben) removal and physicochemical quality improvement of vine (Vitis vinifera) leaf were examined using ultrasonic and traditional cleaning for 5, 10, and 15 min. After an ultrasonic cleaning procedure at 37 kHz for 10 min, acetamiprid, deltamethrin, and pyridaben in vine leaf were reduced by 54.76, 58.22, and 54.55 %, respectively. Furthermore, the total phenolic content (TPC) in vine leaf increased to 13.45 mg GAE/g DW compared to that in control samples using traditional cleaning (10.37 mg GAE/g DW), but there were no significant differences in DPPH radical scavenging activity. After 15 min of conventional cleaning, the total chlorophyll and total carotenoid content of leaves were found to be lowest among all samples, at 6.52 mg/kg and 0.48 mg/kg, respectively. In conclusion, when compared to conventional cleaning methods, ultrasonic cleaning with no chemicals or heat treatment has proven to be a successful and environmentally friendly application in reducing commonly used pesticides and improving the physicochemical qualities of leaves.

Study on heat pipe heat dissipation of high-power ultrasonic transducer

In order to solve the problems of frequency shift, efficiency decline and life shortening caused by temperature rise in the working process of high-power ultrasonic transducer, the technology of heat pipe is employed for enhancing heat dissipation of the ultrasonic transducer. A new type of high-power transducer with heat pipe heat dissipation (HPUT) is proposed in this study. The heat pipe radiator adopts the form of a copper-water-composite wick, and installs straight fins on the condensation section to enhance heat dissipation. Six heat pipe radiators are embedded in the front cover plate of the transducer close to the piezoelectric ceramic and evenly arranged along the circumference of the transducer. The vibration characteristics, radiated sound field characteristics and heat dissipation characteristics of the HPUT are compared with those of traditional Langevin ultrasonic transducer (TLUT) through simulations and experiments. Results manifest that compared with the TLUT, the HPUT has much lower operation temperature (reduced by 60% in this study), much smaller resonant frequency shift (reduced by 75% in this study) and the higher vibration amplitude (increased by 25% in this study). This study will contribute to the development of high-power ultrasonic transducer which has potential application value in many industrial fields.