ORAC is the standard test, adopted by the US Department of Agriculture, to measure the potency of antioxidants in food. .

The test was developed by Dr. Guohua Cao, a physician and chemist who worked at the National Institute on Aging in Baltimore, Maryland.

The ORAC test, though not the be all and end all of antioxidant testing, gives a good idea of the free-radical-destroying potential of a given food. It does this by measuring the time an antioxidant takes to react as well as the capacity of antioxidants within the sample food.

It has been suggested that humans should consume about 5000 ORAC units a day for maximum benefits. Unfortunately, most people do not eat nearly enough vegetables and fruit, or the right type of vegetables and fruit, to achieve this.

For example, to get your daily ORAC dose from apples, you would need to eat 2,294 grams of apple (or about 22 apples). However, as you can see from the below chart, eating just 20 grams of goji berries will cover you.

Fruits ORAC Score Grams Needed to Reach DRI

Goji Berries 25,300 20
Black Raspberries 7,700 65
Prunes 5,770 87
Bilberry 4,460 112
Pomegranates 3,307 151
Raisins 2,830 177
Blueberries 2,400 208
Red Raspberries 2,400 208
Blackberries 2,036 246
Strawberries 1,540 325