Spray‐drying of pomegranate juice with prebiotic dietary fibre

Abstract

SummaryThe 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 0.5 g gCPJ−1 of resistant dextrin was needed to avoid powder stickiness, compared with 1 g gCPJ−1 of maltodextrins and 1.5 g gCPJ−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 gNUTRIOSE gCPJ−1 and 0.10 gCPJ gsolution−1, a liquid feed rate of 1.08 L h−1 and an air temperature of 160 °C. Powders were easily solubilised in water, while storage at 25 °C maintained the pomegranate bioactive components, and there were no stickiness problems for at least 2 months. 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.