Comparison of sucrose and fructo-oligosaccharides as osmotic agents in apple

Abstract

Fructo-oligosaccharides and sucrose were compared as osmotic agents in the osmotic dehydration of apple cv. Idared. Dehydration process of apple cubes (10 ⁎ 10 ⁎ 10 mm) was performed to determine the weight reduction (WR), moisture content (MC), water loss (WL) and solid gain (SG) over a range of osmotic solutions (40–60% w/v), temperature (40–60 °C) and processing time (20–40 min) The effective diffusion coefficient of water and solute was calculated assuming the processes to be governed by Fick's unsteady state diffusion. The effective diffusion coefficients were found to be of the order of 10 − 9 m 2 s − 1 and were effected by the type of solute significantly. The WR, MC, WL and SG were predicted as weighted linear combinations of temperature, concentration of solute and time of OD. The use of fructo-oligosaccharides (FOS) in different fruit based products is an efficient way to enrich human diet with functional component, because of the well-known health benefits of FOS. The osmotic behaviour of fructo-oligosaccharides were studied and compared to the conventional used sucrose. In view of the changes of different osmotics regarding to unit parameters of osmotic dehydration the results give possibility to industrial technology planning of products containing FOS, which are available for consumption in every season of the year and are favourable also in processed form e.g. muesli, dairy products.