Red Delicious, Northern Spy and Ida Red, they say, pack a greater wallop of disease-fighting antioxidants than other apples studied. The researchers, led by Rong Tsao, Ph.D., of Agriculture and Agri-Food Canada in Guelph, Ontario, also pinpointed the individual chemical compounds responsible for antioxidant activity in apples. The findings could lead to the breeding of hybrid apples that pack a heftier antioxidant punch. The report appears in the June 29 issue of the American Chemical Societyâ€™s peer-reviewed Journal of Agricultural and Food Chemistry. ACS is the worldâ€™s largest scientific society. Researchers have long known that apples are a good source of antioxidants, a group of chemicals that scavenge and neutralize unstable molecules called free radicals. Free radicals, which can wreak havoc on cells and tissues, appear to play a role in the onset of heart disease and prostate, colon and other cancers.