Anthocyanin-based natural colorants: A new source of antiradical activity for foodstuff

The antiradical capacity (radical scavenger capacity, RSC) of anthocyanin-b ased fruit extracts prepared in the laboratory (black chokeberry, black-tho rn, and strawberry) was studied by using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH.). To determine their RSC, the second-order rate constant (k( 2)) for the oxidation of these extracts by DPPH. was calculated. The value of k(2) was compared to that used in the food industry as natural (alpha-to copherol) or synthetic (butylated hydroxytoluene (BHT) and butylated hydrox yanisole (BHA)) antioxidants, as well as for a commercial elderberry concen trate and a synthetic colorant (Ponceau 4R). The k(2) values ((mg/mL)(-1) s (-1)), in methanol at 25 degrees C, were 1.87, 0.7, 0.42, 0.2, 0.05, 0.03, and 0.008 for alpha-tocopherol, black chokeberry, BHA, black-thorn, BHT, st rawberry, and elderberry, respectively. Ponceau 4R lacked RSC. Therefore, t hese natural colorants proved to be a combined source of color and RSC for food material.