Changes in Total Phenolics and Anthocyanins during Blackberry, Raspberry and Cherry Jam Processing and Storage

Berries from the Rosaceae family plants are known for their high content in antioxidant compounds, in particular anthocyanins, which proved human health benefits. Blackberry, red raspberry, sweet cherry and wild cherry were processed in jams by a traditional method, without addition of pectin. The influence of jam processing and storage at 18 degrees C for 5 months on the content of total phenolics (TP) and total anthocyanins (TA) was investigated here. Fresh red raspberries showed the highest content of TP, while blackberries showed the highest content of TA. Jam processing diminished the level of the investigated compounds of all fruits - by 66-84% of TA, followed by 61-78% of TP. During jam storage, TP showed better retention compared to TA. Red raspberry jam retained the highest amounts of TP during storage, while wild cherry jam showed better retention of TA during storage compared to the other investigated fruits. Despite the decrease of the level of such antioxidant compounds in jams, this type of processing might be considered a good preservation method as it retained such compounds during 5 months of storage.