Fortification of pomegranate juice with inulin extracted from Jerusalem artichoke for high shelf life prebiotic juice production

Inulin as a prebiotic, in addition to its health effects, can also have many applications in the food industry. One of the important sources of inulin is Jerusalem artichoke, which in this study inulin extraction from it was studied for the production of prebiotic juice. For this purpose, a suspension of Jerusalem artichoke was prepared and removed the impurities from it by the pH change and finally the inulin was bleached. The chemical characteristics and extraction percentage of inulin were calculated and added it to the pasteurized pomegranate juice in proportion of 1.5, 3 and 5%. Physicochemical, sensory, fungi count tests were carried out during one month of storage in the refrigerator. The result showed that inulin extraction was high (87.29%) and polymerization degree was appropriate (46.6%). The presence of inulin in pomegranate juice, in addition to the sweet taste which cause higher score than the control sample in the sensory test, significantly increased shelf-life of juice, so that the number of molds and yeast in the control sample and 5% inulin sample in the fourth week were 150, 50 cfu /ml (p <0.05) respectively. Also, the antioxidant activity reduction in the samples of inulin, especially in the 5% treatment, was less than the control sample during the storage of juice, which can be very significant for the health of the consumer. Increasing the turbidity during the 28 days of preserving prebiotic juice was lower than the control sample, which is important in appearance and marketable characteristics of the product. Finally, inulin can have appropriate antifungal and antioxidant properties in pomegranate juice, which is valuable in shelf life and the quality production of the product, and pomegranate juice containing 3% inulin, according to the best score of the sensory tests, can be selected as a good drink.