The reducing activity and radical scavenging activity of hydrosoluble antioxidants in food compositions from plums during the storage were evaluated. The speeds of changing the reducing activity and radical scavenging activity were different. It was observed that the reducing activity diminished by 63.2% after 62...105 days of storage. The same modification of radical scavenging activity determined in vitro was discovered after 110...254 days of storage. Shelf-life of plum foods was calculated using Weibull distribution. The functional relationship of failure probabilities between the reducing and radical scavenging capacities have been detected (r2= 0. 94-0.98).