Analogical cellular structure changes in solid-liquid contacting operations

Abstract

Mass transfer characteristics are closely related to the cell structures. When cellular material comes in contact with a solution of high concentration, changes in physical properties of cellular material occurred throughout the process at a different degree depending on the process conditions and material matrix characteristics. Six possible situations, Cases I-VI, of changes in cell structure immersed in solution of high concentration are proposed. In this study, the specific influence of red beet tissue shrinkage on mass transfer in 600 g/kg sucrose solution at 25°C is discussed. The changes of cell unit and an analogical cellular structure are discussed. In the solid-liquid contacting period, the situation of volume changes of cell unit of red beet material remained in the no cell volume change (Cases I and II) condition. In most cases, the volume of extracellular space of cellular material decreased with water transfer out of tissue, then material matrix began to collapse, resulting in the changes in porosity. The porosity changes in the no cell volume change cases (Cases I and II) were considered as special conditions without the consideration of cellular material tissue shrinkage. The tissue structure shrinkage cases (Cases III-VI) were considered to occur more often when a fresh, soft cellular material tissue such as fruits and vegetables was contacted with osmotic solution of high concentration.