To improve the vacuum freeze drying rate and to reduce the energy consumption of apple slice, apple slice were treated with different ultrasonic frequency, time and temperature. The vacuum freeze drying rate of treated apple slice was determined and, meanwhile, the rehydration ratio of samples with pre-treatment were determined to compare with those of untreated samples. The results indicated that ultrasonic pre-treatment can significantly improve the drying rate of apple slice, and increase the rehydration rate of the dried apple slice. Under a 100 kHz for 5 min at 25°C, the drying rate of pre-treatments is 1.25 times higher compared with that of the control group.
Abstract. In order to study the mechanism of high voltage pulsed electric field pretreatment on the food drying technology. In this paper, water was treated with high pulse electric field (HPEF) in different frequency, and different voltage, then, the viscosity coefficient and the surface tension coefficient of the water were measured. The results showed that indicated that the viscosity coefficient and the surface tension coefficient of the treated water can be decreased, and while HPEF pre-treatment was applied for 22.5kV at a frequency of 50Hz and 70 Hz, the surface tension and the viscosity coefficient of the pre-treatment treatment were reduced 13.1% and 7.5%, respectively. IntroductionFresh fruits and vegetables have a moisture content ranging from 75 to 90%. They are highly heat sensitive and are apt to be highly perishable. Drying is defined as the reduction of moisture from the products and is an efficient and cheap method for the preservation of fruits and vegetables. Hot air drying is one of the most commonly used procedures in dried food with main disadvantages being prolonged duration and high energy consumption. Therefore it is necessary to explore low power consumption processing for hot air drying.Dry pretreatment technology is utilized to treat food through some physical methods before drying it. Pretreatment can not only improve the quality of dried food but also increase drying rate and thus reduce energy consumption. For example, during the process of drying and dehydration for fruits and vegetables, ultrasound pretreatment certain intensity will enhance their drying rate and thus reduce the drying energy consumption [1][2][3].In recent years, a novel pretreatment technique, high voltage pulsed electric field drying pretreatment technology has been developed only recently, Angers Bach et al. showed an increase in permeability of potato tissue by high intensity electrical field pulse treatment, which resulted in improved mass transfer during fluidized bed drying [4]. Ade-Omowaye et al. found that high voltage pulsed electric field pretreatment could increase the cell membrane permeability and improve the drying rate [5]. Gachovska found that pulsed electric field treatment could increase the drying rate of carrots and enhance the quality of dried carrots [6]. Electrically assisted drying would reduce the processing time, operating temperature, and energy consumption [7]. Other papers reported similar results that pulsed electric field pretreated samples could significantly improve the drying rate [8][9].But, it is not a profoundly explored method of drying pretreatment, and, its mechanism has not been accurately determined, therefore, study the mechanisms of high voltage pulsed electric field pretreatment is one of the important theoretical basis for the technology industrialization application use.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.