Enhancement of Water Transport and Microstructural Changes Induced by High-Intensity Ultrasound Application on Orange Peel Drying

Abstract

Enhancement of water transport and microstructural changes induced by 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 2 Abstract 25The main aim of this work was to evaluate the effect of high intensity ultrasound 26 on drying kinetics of orange peel as well as its influence on the microstructural 27 changes induced during drying. Convective drying kinetics of orange peel slabs 28were carried out at 40 °C and 1 m/s with (AIR+US) and without (AIR) ultrasound 29 application. Drying kinetics analysis was addressed by considering diffusion 30 theory in order to identify the influence of ultrasound on water transport. Fresh, 31 AIR and AIR+US dried samples were analyzed using Cryo-Scanning Electron 32Microscopy. Results showed that drying kinetics of orange peel were 33 significantly improved by the ultrasonic application, which involved a significant 34 (p<0.05) improvement of both mass transfer coefficient and effective moisture 35 diffusivity. The effects on mass transfer properties were confirmed from 36 microstructural observations. In the cuticle surface of flavedo, the pores were 37 obstructed by the spread of the waxy components, this fact evidencing the 38 ultrasonic effects on the interfaces. The cells of the albedo were degraded by 39 application of ultrasound as it brought about large intercellular air spaces 40 facilitating water transfer through the tissue. 41

Effects of Ultrasound on Polyphenol Retention in Apples After the Application of Predrying Treatments in Liquid Medium

“…From a technological point of view, the ultrasound seemed to be very promising, but unfortunately, in some cases, especially when a liquid medium during sonication was applied, substantial losses of bioactive compounds were reported (Stojanovic and Silva 2007;Opalić et al 2009;Pingret et al 2013). Although the available literature presents many experiments with ultrasound application before and during fruit and vegetable dehydration process (Siucińska and Konopacka 2014), the majority of them focus on monitoring the dynamics of mass transfer or physical properties, such as sugar gain, water loss, or changes in color or microstructure of plant tissue (Cárcel et al 2007;Deng and Zhao 2008;Garcia-Perez et al 2012;Nowacka et al 2012;Schössler et al 2012). With regard to phenolic compound retention during ultrasound-assisted fruit tissue treatment, the reports on negative effect of sonication on phenolic compound content and antioxidant activity (Stojanovic and Silva 2007;Opalić et al 2009), more often than not, indicate a positive influence (Keenan et al 2012).…”

Effect of drying conditions on the physical properties of impregnated orange peel

“…The effect of air drying temperature on the functional properties of dietary fiber obtained from orange by-products was evaluated (Garau et al, 2007). The application of high-intensity ultrasound, high speed drying, and solar drying on the drying kinetics of orange peel and its antioxidant activity have been assessed (Garcia-Perez et al, 2012;Senevirathne et al, 2009;Slama and Combarnous, 2011). The increase in pectin yield was investigated as a result of microwave heating of fresh orange peels (Kratchanova et al, 2004).…”

Assessment of Changes in Structure of Dried Tissue of Sour Cherry Pretreated Using Ultrasound-Assisted Osmotic Dehydration

“…Modyfikacja struktury materiałów następuje na skutek mechanicznego oddziały-wania ultradźwięków na tkankę poprzez generowanie przez falę akustyczną zagęsz-czeń i rozrzedzeń ośrodka [9,18]. Wielu autorów dowiodło wpływu US na mikrostrukturę różnych owoców i warzyw [3,4,5,6,16], jednak wśród opracowań brak jest danych dotyczących możliwych skutków oddziaływania ultradźwięków na tkankę owoców pestkowych o kulistym kształcie i zróżnicowanej strukturze.…”

“…[17] oraz Deng i Zhao [2] -dłuższe traktowanie próbek jabłka ultradźwiękami skutkowało większą destrukcją struktury suszu. Zastosowanie US w procesie suszenia skórki pomarańczowej również wywołało podobne rezultaty [9,18]. Stopień deformacji komórek stanowił o ich zagęszczeniu, a tym samym o zwartości konsystencji miękiszu (fot.…”