The effect of different technologies in Pomegranate jam preparation on the phenolic compounds, vitamin C and antioxidant activity

The effect of different gelling agents and processing for jam production from pomegranate juice was evaluated. In the last years, different gelling agents were tested for improving jam quality in terms of color and bioactive compounds. The unsonicated and sonicated pomegranate juices were processed for jam production by microwaves, under vacuum and cryoconcentration concentration methods using low and high methoxy pectins, and carob seed flour as gelling agents. The polyphenols content of sonicated jam was significantly lower than unsonicated samples and cryoconcentrated jams showed the significantly highest value among other methods. The results showed the highest anthocyanin content in the both sonicated and unsonicated jam including carob seed flour and antocyanins content of the cryoconcentrated samples was in the range of 156.6-186.2 mg/kg, and revealed higher content compared to the other processed samples.The findings showed that cryoconcentrated method is more effective in preserving the total polyphenols, anthocyanins, vitamin C and antioxidant activity. Moreover, also the colour of cryoconcentrated pomegranade jam was preserved. Cryoconcentration is a promising method for preserving organoleptic and functional properties of the jam produced from pomegranate juice.