Kinetic Modeling and Mass Diffusivities during Osmotic Treatment of Red Abalone (H aliotis rufescens ) Slices

Abstract

Osmotic dehydration of abalone slices was carried out in order to look into the influence of osmotic concentration (15, 20 and 25% NaCl w/v) and solution temperature (25, 45 and 65C) on mass transfer kinetics and diffusion coefficients. Moisture and solid diffusivities values were 2.70–10.76 × 10−10 and 1.31–2.41 × 10−10 m2/s, respectively. Activation energy values from 23.56 to 80.24 kJ/mol for both diffusivities were estimated. Moisture and solid diffusion coefficients were influenced by both factors. A multiple linear regression test was performed on the combined effect of osmotic concentration and solution temperature during osmotic treatment. Modeling of mass transfer kinetics for moisture loss and solid gain were performed according to three mathematical models: Penetration, Magee and Azuara. Thus, based upon statistical tests (R2, sum squared error, root mean square error and χ2), the Azuara model was the most suitable to describe the mass transfer phenomena during osmotic process of abalone slices. Practical Applications The abalone has a great demand in international markets, even when it is pretty expensive, thus the need to increase its shelf life is relevant from an economic point of view as well as quality product. Therefore, osmotic dehydration is an excellent alternative, as the abalone is cooked and simultaneously preserved under a salt solution. Furthermore, this osmotic treatment could also act further on as a pretreatment for any other drying method either by convective, freeze-drying, microwave, etc. That is why, this work proposes to research the effects of osmotic concentration and solution temperature on the kinetics of mass transfer during osmotic dehydration of abalone slices samples by different mathematical models. Thereby, osmotic treatment modeling of abalone slices, under conditions stated earlier, could be very helpful in predicting moisture/salt final content and process times as well as anticipating and dealing any problem during processing.