Abstract: In order to improve the quality of blueberry jam during its processing, changes in anthocyanin content, total phenol content and 1,1-dipheny1-2-picryl-hydrazyl (DPPH) and 2,2’-amino-di(3-ethyl-benzothiazoline sulphonic acid-6) ammonium salt (ABTS) radical scavenging activities of blueberry jam at different stages of processing such as pulping, formulation, filling and sterilization were detected. The effect of added sodium D-isoascorbate on the functional components of blueberry jam was studied as well as its inhibitory effect on the loss of antioxidant activity. Meanwhile, changes in anthocyanin content, total phenol content, and L*, a* and b* values were measured during storage. Anthocyanin content, total phenol content and antioxidant activity gradually decreased during the whole production process. This decrease was slowed down by addition of sodium D-isoascorbate. During incubation at constant temperature, the degree of fading was reduced by about 21.07% by adding sodium D-isoascorbate. Thus, addition of sodium D-isoascorbate can improve the nutritional quality and stability of blueberry jam and prolong its shelf life.

Key words: sodium D-isoascorbate, blueberry jam, quality, total phenol, anthocyanin