Assessing enzyme activity to obtain a new functional prebiotic jam

The aim of this study was to formulate a new prebiotic jam from citrus fruits by enzymatic treatment in order to propose a new functional food. A preliminary study was carried out with three commercial enzymes to evaluate the process conditions and prebiotic activity. In addition, the prebiotic effect on probiotic strains was evaluated before and after enzyme treatment. During the storage, physico-chemical properties, antioxidant activity, microbiological and sensory analyses were performed. The results showed that the enzyme treatment of the jam allowed the probiotic bacteria to increase their growth of two logarithmic units respect to the control. In addition, all the physico-chemical analyses highlighted that the antioxidant compounds were stabilised by the hydrolysed pectins. Regarding the sensory profile, only the odour and bitterness decreased statistically compared to the initial sample, while the results of the consumer test reached high evaluation values. The results confirmed how enzymatic treatment of the fruit pectin enables the production of a new low-cost- functional jam with high added value.