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

The main aim of this work was to evaluate the effect of high-intensity ultrasound (US) on the drying kinetics of orange peel as well as its influence on the microstructural changes induced during drying. Convective drying kinetics of orange peel slabs were carried out at a relative humidity of 26.5±0.9%, 40 °C and 1 m/s with (AIR+US) and without (AIR) ultrasound application. In order to identify the US effect on water transport, drying kinetics were analyzed by taking the diffusion theory into account. Fresh, AIR and AIR+US dried samples were analyzed using Cryo-Scanning Electron Microscopy. Results showed that the drying kinetics of orange peel were significantly improved by US application, which involved a significant (p<0.05) improvement of mass transfer coefficient and effective moisture diffusivity. The effects on mass transfer properties were confirmed with microstructural observations. In the cuticle surface of flavedo, the pores were obstructed by the spread of the waxy components, this fact evidencing US effects on the air solid interfaces. Furthermore, the cells of the albedo were disrupted by US, as it created large intercellular air spaces facilitating water transfer through the tissue.The authors would like to acknowledge the financial support of MICINN and CEE (European Regional Development Fund) from projects Ref. DPI2009-14549-C04-04, PSE-060000-2009-003, and FP6-2004-FOOD-23140 HIGHQ RTE.García Pérez, JV.; Ortuño Cases, C.; Puig Gómez, CA.; Cárcel Carrión, JA.; Pérez Munuera, IM. (2012). Enhancement of Water Transport and Microstructural Changes Induced by High-Intesity Ultrasound Application on Orange Peel Drying. Food and Bioprocess Technology. 5(6):2256-2265. https://doi.org/10.1007/s11947-011-0645-0S2256226556Alandes, L., Perez-Munuera, I., Llorca, E., Quiles, A., & Hernando, I. (2009). 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Accessed 15 January 2010.Fernandes, F. A. N., Gallao, M. I., & Rodrigues, S. (2008a). Effect of osmotic dehydration and ultrasound pre-treatment on cell structure: Melon dehydration. Food Science and Technology, 41(4), 604–610.Fernandes, F. A. N., Oliveira, F. I. P., & Rodrigues, S. (2008b). Use of ultrasound for dehydration of papayas. Food and Bioprocess Technology, 1(4), 339–345.Gabaldon-Leyva, C. A., Quintero-Ramos, A., Barnard, J., Balandrán-Quintana, R., Talamás-Abbud, R., & Jiménez-Castro, J. (2007). Effect of ultrasound on the mass transfer and physical changes in brine bell pepper at different temperatures. Journal of Food Engineering, 81(2), 374–379.Gallego-Juárez, J. A. (1998). Some applications of air-borne power ultrasound to food processing. In M. J. W., Povey, T. J. Mason (Eds.), Ultrasound in Food Processing. UK: London, Chapman & Hall.Gallego-Juárez, J. A., Rodríguez-Corral, G., Gálvez-Moraleda, J. C., & Yang, T. S. (1999). A new high intensity ultrasonic technology for food dehydration. Drying Technology, 17(3), 597–608.Garau, M. C., Simal, S., Femenia, A., & Rosselló, C. (2006). Drying of orange skin: drying kinetics modelling and functional properties. Journal of Food Engineering, 75(2), 288–295.Garau, M. C., Simal, S., Rossello, C., & Femenia, A. (2007). Effect of air-drying temperature on physico-chemical properties of dietary fibre and antioxidant capacity of orange (Citrus aurantium v. Canoneta) by-products. Food Chemistry, 104(3), 1014–1024.Garcia-Perez, J. V., Cárcel, J. A., De la Fuente, S., & Riera, E. (2006). Ultrasonic drying of foodstuff in a fluidized bed. Parametric study. Ultrasonics, 44, 539–543.Garcia-Perez, J. V., Cárcel, J. A., Benedito, J., & Mulet, A. (2007). Power ultrasound mass transfer enhancement in food drying. Food and Bioproducts Proccessing, 85(3), 247–254.Guiné, R. P. F., Henrriques, F., Barroca, M. J. (2010). Mass transfer coefficients for the drying of pumpkin (Cucurbita moschata) and dried product quality. Food and Bioprocess Technology. doi: 10.1007/s11947-009-0275 , in press.Khalloufi, S., Almeida-Rivera, C., & Bongers, P. (2009). A theoretical model and its experimental validation to predict the porosity as a function of shrinkage and collapse phenomena during drying. Food Research International, 42(8), 1122–1130.Larrauri, J. A., Rupérez, P., Bravo, L., & Saura-Calixto, F. (1996). High dietary fibre powders from orange and lime peels: associated polyphenols and antioxidant capacity. Food Research International, 29(8), 757–762.Mujumdar, A. S., & Law, C. L. (2010). Drying technology: trends and applications in postharvest processing. Food and Bioprocess Technology, 3(6), 843–852.Mulet, A., Blasco, M., García-Reverter, J., & Garcia-Perez, J. V. (2005). Drying kinetics of Curcuma longa rhizomes. Journal of Food Science, 7(5), 318–323.Oliveira, F. I. P., Gallao, M. 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Effect of Ultrasonic-Assisted Blanching on Size Variation, Heat Transfer, and Quality Parameters of Mushrooms

The main aim of this work was to assess the influence of the application of power ultrasound during blanching of mushrooms (60 90 °C) on the shrinkage, heat transfer, and quality parameters. Kinetics of mushroom shrinkage was modeled and coupled to a heat transfer model for conventional (CB) and ultrasonic-assisted blanching (UB). Cooking value and the integrated residual enzymatic activity were obtained through predicted temperatures and related to the hardness and color variations of mushrooms, respectively. The application of ultrasound led to an increase of shrinkage and heat transfer rates, being this increase more intense at low process temperatures. Consequently, processing time was decreased (30.7 46.0 %) and a reduction in hardness (25.2 40.8 %) and lightness (13.8 16.8 %) losses were obtained. The best retention of hardness was obtained by the UB at 60 °C, while to maintain the lightness it was the CB and UB at 90 °C. For enhancing both quality parameters simultaneously, a combined treatment (CT), which consisted of a CB 0.5 min at 90 °C and then an UB 19.9min at 60 °C, was designed. In this manner, compared with the conventional treatment at 60 °C, reductions of 39.1, 27.2, and 65.5 % for the process time, hardness and lightness losses were achieved, respectively. These results suggest that the CT could be considered as an interesting alternative to CB in order to reduce the processing time and improve the overall quality of blanched mushrooms.The authors acknowledge the financial support of Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional de La Plata from Argentina, Erasmus Mundus Action 2-Strand 1 and EuroTango II Researcher Training Program and Ministerio de Economia y Competitividad (SPAIN) and the FEDER (project DPI2012-37466-CO3-03).Lespinard, A.; Bon Corbín, J.; Cárcel Carrión, JA.; Benedito Fort, JJ.; Mascheroni, RH. (2015). 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Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field