Integrated approach on solar drying, pilot convective drying and microstructural changes

Abstract Solar drying of foods is an old technique, still used nowadays. Nevertheless, the mathematical approach of the complex phenomena involved is not completely integrated. Drawbacks appear in modelling heat transport, specially related to the huge variability of meteorological factors. The great dependence of the heat and mass transfer model parameters on water content is also frequently forgotten. Macroscopic changes (e.g. shrinkage) that occur during drying processes, are usually not considered in mass transfer equations, also affecting the predictive ability of the models. The objective of this work was to develop the mathematical basis and considerations for integrating heat and mass transfer phenomena, taking into consideration macroscopic changes and their correlation to changes at microscopic level (e.g. cellular shrinkage), that might occur during solar drying of grapes.

[1]  H. Ramaswamy,et al.  Processing fruits : science and technology , 2005 .

[2]  J. L. Woods,et al.  Moisture Diffusion and Desorption Isotherms for Banana , 2000 .

[3]  Antonio Mulet,et al.  Drying modelling and water diffusivity in carrots and potatoes , 1994 .

[4]  Jorge E. Lozano,et al.  Shrinkage, Porosity and Bulk Density of Foodstuffs at Changing Moisture Contents , 1983 .

[5]  S. Sablani,et al.  A Method of Determination of Concentration Dependent Effective Moisture Diffusivity , 1995 .

[6]  A. Crafts.  CELLULAR CHANGES IN CERTAIN FRUITS AND VEGETABLES DURING BLANCHING AND DEHYDRATION , 1944 .

[7]  Alberto M. Sereno,et al.  Modelling shrinkage during convective drying of food materials: a review , 2004 .

[8]  Hideaki Hosaka,et al.  SHRINKAGE IN DEHYDRATION OF ROOT VEGETABLES , 1976 .

[9]  W. Price,et al.  Factors influencing the drying of prunes 1. Effects of temperature upon the kinetics of moisture loss during drying , 1996 .

[10]  Zacharias B. Maroulis,et al.  Water sorption isotherms of raisins, currants, figs, prunes, and apricots , 1990 .

[11]  J. L. Woods,et al.  Solar Drying of Bananas: Mathematical Model, Laboratory Simulation, and Field Data Compared , 2000 .

[12]  R. M. Peart,et al.  CIGR handbook of agricultural engineering, Volume 5: Energy and biomass engineering. , 1999 .

[13]  D K Salunkhe,et al.  Food dehydration by solar energy. , 1982, Critical reviews in food science and nutrition.

[14]  S. Simal,et al.  Moving Boundary Model For Simulating Moisture Movement In Grapes , 1996 .

[15]  José Miguel Aguilera,et al.  Microstructural principles of food processing and engineering , 1999 .

[16]  J. G. Brennan.  Food dehydration : a dictionary and guide , 1994 .

[17]  M. J. Urbicain,et al.  Computer model of shrinkage and deformation of cellular tissue during dehydration , 1989 .

[18]  K. S. Jayaraman,et al.  DEHYDRATION OF FRUITS AND VEGETABLES - RECENT DEVELOPMENTS IN PRINCIPLES AND TECHNIQUES , 1992 .

[19]  Alan Shivers Foust,et al.  Principles of unit operations , 1960 .

[20]  S. Sahin,et al.  Physical properties of foods , 2006 .

[21]  Cristina L. M. Silva,et al.  Quantification of microstructural changes during first stage air drying of grape tissue , 2004 .

[22]  John Crank,et al.  The Mathematics Of Diffusion , 1956 .

[23]  Brian P. Hills,et al.  NMR studies of changes in subcellular water compartmentation in parenchyma apple tissue during drying and freezing , 1997 .

[24]  Robert H. Driscoll,et al.  The thin-layer drying characteristics of garlic slices , 1996 .

[25]  G. Mazza,et al.  Dehydration of onion: some theoretical and practical considerations , 2007 .

[26]  Antonio Mulet,et al.  DRYING OF CARROTS. I. DRYING MODELS. , 1989 .

[27]  G. Vázquez,et al.  EFFECTS OF VARIOUS TREATMENTS ON THE DRYING KINETICS OF Muscatel GRAPES , 2000 .

[28]  W. Muehlbauer,et al.  CIGR Handbook of Agricultural Engineering, Volume V Energy and Biomass Engineering, Chapter 2 Energy for Biological Systems, Part 2.3 Solar Energy , 1999 .

[29]  Arun S. Mujumdar,et al.  Drying of Fruits , 2004 .

[30]  Zhao Yusheng,et al.  Diffusion in potato drying , 1988 .

[31]  Chris T. Kiranoudis,et al.  Heat and mass transfer modeling in air drying of foods , 1995 .

[32]  R. Moreira,et al.  SHRINKAGE OF APPLE DISKS DURING DRYING BY WARM AIR CONVECTION AND FREEZE DRYING , 2000 .

[33]  Madeehah Prado,et al.  SHRINKAGE OF DATES (Phoenix Dactilyfera L.) DURING DRYING , 2000 .

[34]  C. S. Mccleskey,et al.  BACTERIOLOGICAL STUDIES OF FRESH CRABMEAT , 1941 .

[35]  Z. Maroulis,et al.  EFFECT OF DRYING METHOD ON SHRINKAGE AND POROSITY , 1997 .

[36]  J. Fohr,et al.  CRAPE DRYING : FROM SAMPLE BEHAVIOUR TO THE DRIER PROJECT , 1992 .

[37]  Vaios T. Karathanos,et al.  Comparison of Two Methods of Estimation of the Effective Moisture Diffusivity from Drying Data , 1990 .

[38]  B. K. Bala,et al.  Simulation of the indirect natural convection solar drying of rough rice , 1994 .

[39]  Servet Gulum Sumnu,et al.  Thermal Properties of Foods , 2006 .

[40]  J. M. Coulson,et al.  Heat Transfer , 2018, Finite Element Method for Solids and Structures.

[41]  E. Jorge,et al.  THERMAL PROPERTIES OF FOODS , 1997 .

[42]  Zacharias B. Maroulis,et al.  DENSITIES, SHRINKAGE AND POROSITY OF SOME VEGETABLES DURING AIR DRYING , 1994 .