Processing and storage impact on the antioxidant properties and color quality of some low sugar fruit jams

Abstract

The aim of the present study was to assess the effect of thermal processing and storage period on the antioxidant properties and color quality of strawberry, sweet and sour cherry low sugar jam. It was observed that thermal processing of fruits led to statistical significant alterations for all monitored parameters. Most important losses due to thermal processing were recorded for monomeric anthocyanins (92-93% from the value recorded in frozen fruits), followed by vitamin C content (54-78%), FRAP values (30-41%) and total phenolics content (25-43%). Additional, alterations of measured parameters occur during storage. Jams storage for a period of 3 months at 20°C led to a decrease in vitamin C content of 22-33% from the value recorded one day after processing and a loss of anthocyanins content, ranging from 22% in sour cherries jam to 33% in strawberry jam related to the value recorded one day after processing. The FRAP values showed not statistical significant alterations after 3 months of storage. Also, there was an increase in polymeric color in the range of 39-63% from the value recorded one day after processing while for the color density there were no statistically significant alterations. The practical implications of this work are that the derived knowledge could be very useful to optimize jam processing technology and storage conditions in order to improve the quality of these products.