Osmotic Dehydration Kinetics of Plantain (Musa paradisiaca) using a Low-calorie Sugar

Abstract

Plantain is consumed as a stable food in most sub-Saharan countries and to some extent in southern America and Asia. To avoid deterioration of the plantain after harvest and to provide food variety, a reasonable quantity of plantain is now being transformed into flour. Osmotic dehydration (OD) is a critical step in the flour production process because it enhances the nutritional and sensory quality of the flour. There are concerns to use alternative osmotic agents to sucrose and salts to avoid their high content in the final product which have an adverse effect on the health of consumers. Suitable alternatives are low-calorie sugars (LCS) because they have low glycemic indices but which unfortunately have not been tested for the OD of plantain. The aim of this work was to study the osmotic dehydration of unripe plantain using a commonly consumed commercial LCS (Sussli) as an osmotic agent. The influence of process variables (thickness, concentration, sample/solution ratio and temperature) on mass transfer parameters; water loss (WL) and solute gain (SG) on osmotic dehydration of plantain (Musa paradisiaca) were evaluated. All parameters studied had a significant influence on weight loss and solid gain. The kinetics of the osmotic dehydration was modeled using the Azuara, Peleg and Page models. Plantain slice of thickness 5 mm, LCS solution concentration of 50% at ambient temperature (25 ± 2°C), and a sample/solution ratio of 1:10 (w/v) was judged best for osmotic treatment of plantains in LCS. Under these conditions the weight loss and solid gain were 20% and 1.73% respectively. The Peleg model best described the dehydration kinetics with the highest R2 (0.999) and the least RMSE.