Modeling of Water Loss during Osmotic Dehydration of Apple Cubes in Sugar Beet Molasses

Abstract

Application of the Peleg model was investigated for predicting water loss (WL) during osmotic dehydration of apples in sugar beet molasses at different concentrations (40–80 °Bx) and temperatures (45–65C). Analyses of variance was used in order to find significant effects of temperature, dry matter content of solution and time on WL. All analyzed variables showed statistically significant influence on WL at α = 0.05 (F > Fα). The strongest impact on WL has dry matter content in molasses while the weakest has a temperature. High values of coefficient of determination, obtained for Peleg's constants k1 and k2, indicate that Peleg's model satisfactory fit experimental data. By defining the dependence of Peleg's constants on temperature and dry matter content, new mathematical model for WL was developed. High values of coefficient of determination (R2 = 0.933) and low standard deviation (SD = 0.043) show that new model describes well the experimental data. Practical Applications Osmotic dehydration is the method appropriated to reduce postharvest losses of fruits, and a common process for producing dried fruits, which can be directly consumed as snacks or used as an ingredient in cakes, pastries, yoghurts and many others food products. This study intends to investigate the effects of concentration, osmotic solution temperature and immersion duration on the kinetics of mass transfer. With Peleg's equation as initial model, we developed good and simplified mathematical model water loss (WL), during osmotic dehydration of apples in sugar beet molasses. With the model, the prediction of WL for apple cubes, under conditions stated above, could be very simple and fast.