It may be useful to some of you for food selection.
Table compiled from this systematic review: http://jn.nutrition.org/content/132/3/461.long
As a reminder, oxidative stress (what antioxidant are preventing) is implicated in most "modern" disease: Cancer, Parkinson's, Alzheimer's, Atherosclerosis, Diabetes, Heart failure, Myocardial infarction, Schizophrenia, Bipolar disorder, Erectile dysfunction and many more....
Food name [Food type] Amount of antioxidant in mmol/100g
Dog rose [berries] 39.46
Walnut [Nuts and seeds] 20.97
Pomegranate [Fruits] 11.33
Crowberry [berries] 9.17
Blueberry/ bilberry, wild [berries] 8.23
Blackcurrant [berries] 7.35
Strawberry, wild [berries] 6.88
Blackberry, wild [berries] 6.13
Sour cherry [berries] 5.53
Sunflower seed [Nuts and seeds] 5.39
Blackberry, cultivated [berries] 5.07
Cowberry/ cranberry [berries] 5.03
Elderberry [berries] 4.31
Raspberry, wild [berries] 3.97
Ginger [Roots and tubers] 3.76
Blueberry, cultivated [berries] 3.64
Apricot, dried [Dried fruits] 3.24
Raspberry [berries] 3.06
Cloudberry [berries] 2.83
Prune [Dried fruits] 2.6
Chilipepper [Vegetables] 2.46
Rowanberry [berries] 2.42
Kale/curly kale [Vegetables] 2.34
Strawberry, cultivated [berries] 2.17
Buck wheat, wholemeal flour [Cereals] 1.99
Red beet [Roots and tubers] 1.98
Red cabbage [Vegetables] 1.88
Broad bean/ fava bean [Pulses] 1.86
Orange/yellow pepper [Vegetables] 1.85
Redcurrant [berries] 1.78
Parsley [Vegetables] 1.7
Artichoke, leaves [Vegetables] 1.67
Red/green pepper [Vegetables] 1.64
Grape [Fruits] 1.45
Gooseberries [berries] 1.45
Buck wheat, white flour [Cereals] 1.23
Sesame seed [Nuts and seeds] 1.21
Brussels sprout [Vegetables] 1.14
Orange [Fruits] 1.14
Pinto bean/ black bean [Pulses] 1.14
Barley, wholemeal flour [Cereals] 1.09
Ground nut/ peanut [Pulses] 1.08
Plum [Fruits] 1.06
Pineapple [Fruits] 1.04
Lemon [Fruits] 1.02
Date [Fruits] 1.02
Sweet cherry [berries] 1.02
Spinach [Vegetables] 0.98
Kiwi fruit [Fruits] 0.91
Clementine [Fruits] 0.9
Asparagus [Vegetables] 0.85
Grapefruit [Fruits] 0.83
Common millet, wholemeal flour [Cereals] 0.82
Soya beans [Pulses] 0.82
Blue potato [Roots and tubers] 0.8
Celery [Vegetables] 0.8
Raisins [Dried fruits] 0.8
Fig, dried [Dried fruits] 0.76
Lime [Fruits] 0.73
Fig [Fruits] 0.73
Artichokes, heart [Vegetables] 0.69
Onion [Vegetables] 0.67
Black-eyed pea/ bean [Pulses] 0.65
Papaya [Fruits] 0.62
Maize, white flour [Cereals] 0.6
Oats, rough oatmeal [Cereals] 0.59
Barley, white flour [Cereals] 0.58
Broccoli [Vegetables] 0.58
Apricot [Fruits] 0.52
Lentils [Pulses] 0.49
Hazelnut [Nuts and seeds] 0.49
Rye, wholemeal flour [Cereals] 0.47
Leek [Vegetables] 0.47
Kaki/sharon [Fruits] 0.43
Okra [Vegetables] 0.41
Avocado [Vegetables] 0.41
Savoy cabbage [Vegetables] 0.41
Swede/rutabaga [Roots and tubers] 0.4
Radish [Vegetables] 0.4
Kidney beans [Pulses] 0.38
Mango [Fruits] 0.35
Mung bean [Pulses] 0.35
Lettuce [Vegetables] 0.34
Wheat, wholemeal flour [Cereals] 0.33
Oats, white flour [Cereals] 0.32
Bulgur wheat, wholemeal flour [Cereals] 0.31
Tomato [Vegetables] 0.31
Sorghum, wholemeal flour [Cereals] 0.3
Almond [Nuts and seeds] 0.3
Turnip [Roots and tubers] 0.29
Apple [Fruits] 0.29
Common millet, white flour [Cereals] 0.25
Sweet potato/batat [Roots and tubers] 0.24
Garlic, dried [Vegetables] 0.24
Rye, white flour [Cereals] 0.23
Cauliflower [Vegetables] 0.23
Chickpeas [Pulses] 0.23
Cashew nut [Nuts and seeds] 0.23
Yam [Roots and tubers] 0.22
Garlic [Vegetables] 0.21
Banana [Fruits] 0.2
Maize [Vegetables] 0.19
Pear [Fruits] 0.18
Cassava, manioc, yuka [Roots and tubers] 0.17
Rice, grains [Cereals] 0.17
Aubergines/ eggplant [Vegetables] 0.17
Plantain [Fruits] 0.17
Horned melon [Fruits] 0.16
Cantaloupe melon [Fruits] 0.15
Wheat, white flour [Cereals] 0.13
Garden pea [Pulses] 0.12
Endive [Vegetables] 0.1
Potato [Roots and tubers] 0.09
Parsnip [Roots and tubers] 0.09
Cabbage [Vegetables] 0.09
Squash [Vegetables] 0.08
Fennel [Vegetables] 0.07
Durum wheat, white flour [Cereals] 0.05
Cucumber [Vegetables] 0.05
Carrot [Roots and tubers] 0.04
Rice, white flour [Cereals] 0.04
Watermelon [Fruits] 0.04
Zucchini/ courgettes [Vegetables] 0.02