Effect of viscosity and rheological behavior on selective mass transfer during osmotic dehydration of mango slices in natural syrups

摘要

Osmotic dehydration of mangoes was investigated for the reduction of solids gain (SG) and potential use of natural syrups as osmotic solutions. Different osmotic solutions at 60 degrees Brix were used (made with sucrose, glucose, fructose, corn syrup solids (CSS), and agave syrup (AS) with or without added xanthan gum [XG] or inulin) during osmotic dehydration at 40 degrees C of mango slices (0.4 and 1.5 cm thickness). Rheological behavior and viscosity of the different osmotic solutions were determined at 22 and 40 degrees C. According to the results, increasing the viscosity and the sample thickness helped to reduce the sugar gain while maintaining an adequate water loss. The highest sugar gain was found for sucrose, glucose, fructose, AS solutions, and the lowest, for CSS solutions and XG added to AS. The impact of increasing apparent viscosity on SG was more pronounced for thin samples, indicating the importance of the Biot number on selective mass transfer during osmotic dehydration.Practical Applications This research aims to obtain osmotically dehydrated mangoes with low sugar content by using a natural multicomponent solution such as an AS with added ingredients. In this study, the role of solution viscosity combined to sample thickness in lowering SG during osmotic dehydration was elucidated. As well, AS used in this research as a model, is particularly interesting due to its rich content in vitamins and prebiotic (inulin) which levels up the mango nutritious values. This study would help industrials to offer healthier snacks, in particular for consumers who wish to reduce their sugar intake.