Spray-drying of pomegranate juice with prebiotic dietary fibre

The prebiotic fibres, resistant dextrin and fructooligosaccharides (FOS), were studied for use as drying-aid agents for the spray-drying of concentrated pomegranate juice, a low-caloric juice containing interesting health-related compounds. Resistant dextrin was the best drying-aid agent as only 0.5gg(CPJ)(-1) of resistant dextrin was needed to avoid powder stickiness, compared with 1gg(CPJ)(-1) of maltodextrins and 1.5gg(CPJ)(-1) of fructooligosaccharides. The best conditions for spray-drying a concentrated pomegranate juice (62.6% dry matter) using the resistant dextrin (NUTRIOSE) were 1.25 g(NUTRIOSE)g(CPJ)(-1) and 0.10 g(CPJ)g(solution)(-1), a liquid feed rate of 1.08Lh(-1) and an air temperature of 160 degrees C. Powders were easily solubilised in water, while storage at 25 degrees C maintained the pomegranate bioactive components, and there were no stickiness problems for at least 2months. Resistant dextrin could be used with all kind of fruit juices in substitution of maltodextrins, and the resulting prebiotic powders could be employed for formulating novel functional foods.