Comparison of the effect of inulin, fructooligosaccharide and polydextrose on physicochemical characteristics of clear apple juice during six month storage at 4˚C and 25˚C

Aim of this study was to produce prebiotic clear apple juice that in addition to having healthy effects for consumers could keep its quality properties. In this investigation Inulin, fructooligosaccharide and polydextrose, were added to clear apple juice as prebiotic components in three dosages: 1.5, 2.5 and 3.5 percent and one sample was prepared as a blank without adding any prebiotic. All samples were held in 4˚^C and 25˚^C for 6 month and some of their physicochemical characteristics including soluble solids (Brix), reduced sugar and total sugar were measured in the first day of production and at intervals of one month for the whole 6 months. The results showed that with adding prebiotic the amount of Brix, reduced sugar and total sugar was increased. For Brix it became of 14.1% in control sample to 17.6% in samples that contain prebiotic, reduced sugar was 9.45 g/100 ml in blank and after adding prebiotic it became up to 10, total sugar was near 12 in blank and after adding prebiotic it became 13 and 14 up to kind of prebiotic. The most amounts for reduced sugar was in samples containing poly dextrose and the least amount was in samples containing inulin. For total sugar the most amounts was in samples containing inulin and the least amount was in samples containing polydextrose. Increasing in dosage of prebiotic increases the variation amount in comparison to blank sample and samples contain less prebiotic. With increasing of the temperature and time of storage the rate of reduced sugar changing increased and total sugar changing decreased for each sample in comparison to the control sample and it doesn't any effect on Brix. Samples with prebiotic were sweeter than blank in result of their sugar content and inulin and fructooligosaccharide create sweetener product.