Phenolic Content and Radical Scavenging Capacity of Berries and Related Jams from Certificated Area in Serbia

Chemical composition and the effects of domestic processing and storage were studied in organically cultivated or wild growing berries, harvested in certificated area in Serbia. The total phenolics content in fresh berries ranged from 380 to 1660 mg GAE/100 g. The phenolic content decreased during the processing to jams, and storage in almost all samples, except in black currant. Among fresh berries, the highest amount of total anthocyanins was found in bilberry (0.61 +/- 0.03 %). Processing and storage caused decrease in anthocyanin content. The most ubiquitous anthocyanin aglycone was found to be cyanidin. Ellagic acid was detected in fresh and frozen black raspberries and related jams, and its content increases during thermal processing to jam. Among fresh berries, bilberry showed the strongest DPPH radical scavenging activity with an IC(50) value of 0.82 mg/ml. However, frozen as well as processed berries in our study still showed comparable high values of radical scavenging activity. After 9 months of storage all investigated jams were microbiologicaly correct. Regardless of the losses in the amount of total phenolics, total anthocyanins and radical scavenging activity, frozen berries and related jams are still excellent sources of nutritional substances with antioxidant potential.