Currently, a major trend in the food industry presents the production of food with sweet taste with reduced saccharose added. Jams low in sucrose differ from traditional jams by an increased content of biologically active compounds, in particular, compounds from the family of polyphenols. The validity of the quality of jam with low sucrose content depends on the oxido-reductive state of antioxidants. The study of stability duration of active antioxidants in those jams composition was examined using Weibull distribution. It has been shown that changing the oxido-reductive state of jam takes place involving chemical compounds of flavonoids class. The stability duration of flavonoids and validity of jam quality is 90 – 160 days depending on the content of antioxidants in fruits.