Organic produce has been found to be higher in antioxidants than its conventional counterparts.
A 2002 Italian study (their National Institute of Food and Nutrition Research) has found organic pears, peaches and oranges had higher antioxidant levels than their conventional counterparts. Organic William's pears particularly, contain less fiber but more natural sugar, vitamin C and antioxidants compared to their conventional counterparts, and were more resistant to mildew and fungi.
Antioxidant levels in sustainably grown corn were 58.5 percent higher than conventionally grown corn, while organically and sustainably grown marionberries had approximately 50 percent more antioxidants than conventionally grown berries, according to a 2003 University of California at Davis study. Sustainably and organically grown strawberries had about 19 percent more antioxidants than their conventional counterparts.
Organic lemonade can have ten times more eriocitrin (an antioxidant) than a glass of lemonade from conventionally grown lemons, according to a 2007 study by Washington State University supported by The Organic Center. The study assessed of the bioavailability of three chiral flavonoids (hesperetin, naringenin, and eriocitrin) that are found in citrus fruits and juices. Organic lime juice had three times the level of eriocitrin compared to conventional lime juice.
Flavonoids increase over a ten year period in crops grown in organically farmed fields, according to research at the University of California-Davis. Organic tomatoes had 79 and 97 percent more quercetin and kaempferol aglycones (beneficial flavonoids) that their conventionally grown counterparts over a ten-year period
Organically-produced food had higher levels of antioxidants and lower mycotoxin levels than conventionally-grown samples in a Newcastle University study (2005). Grass-based organic cattle diets reduce the risk of E. coli contamination while grain-based conventional diets (often in high-density feedlots) increase the risk.