Capsicum

Food · Vegetable · Food, Typed Supps

Green capsicums are just unripe red ones — and ripening is what builds the vitamin C and colour.

Stage by stage

Intake (Cells ruptured): Chewing breaks the cell walls and releases ascorbate held in solution.
Digestion (No breakdown needed): Vitamin C needs no digestion; carotenoids stay bound in the pigment bodies until heat or fat releases them.
Absorption (Transported into blood): Vitamin C crosses by saturable transporters; beta-carotene needs bile and dietary fat to follow.
Tissues (Collagen and immune cells): Ascorbate is used in collagen synthesis and concentrated in immune cells; carotenoids are stored and partly converted to vitamin A.

Time to effect

Hours: Plasma vitamin C rises within a few hours of eating one.

Allergens

None of the fourteen major allergens. Derived from what this food is, not from a product label.

Eating patterns

Fits: Vegan, Vegetarian, Pescatarian, Halal, Kosher, Keto, Low-FODMAP, Gluten-free.

In season

July to October in the northern hemisphere, January to April in the southern.

Satiety

The satiety index is measured on 240 kcal servings. At 27 kcal per 100 g that is 889 g of this, which is not a serving anyone eats — so the index has nothing to say about it.

Environmental footprint

0.5 kg CO2e and 108 litres of freshwater per kg, matched to "Other vegetables" in Poore & Nemecek (2018), Science 360.

Cost band

Cheap — roughly £2.5 per kg, as a band midpoint rather than a price.

Key nutrients

Nutrition per 100g

Calories: 27
Protein: 1.1g
Carbohydrate: 4.4g
of which sugars: 4.4g
Fat: 0.4g
of which saturated: 0g
Fibre: 1.1g
Sodium: 3mg

Food vs. supplement

A red capsicum supplies several times a day's vitamin C alongside carotenoids, vitamin E and folate. Isolated ascorbate tablets match the number on one nutrient and nothing else, and absorbed fraction drops as the dose rises.

Kitchen tip

Cut close to serving and eat raw for vitamin C. If the goal is the orange-red carotenoids instead, cook briefly with a little oil — they are not usefully absorbed without fat.

Common myth

“Green, yellow and red capsicums are different vegetables with different uses.” In reality: They are the same fruit at different ripeness. Green is picked unripe, and carries roughly half the vitamin C and a fraction of the beta-carotene of the fully ripened red fruit.