Cumquat

Food · Fruit · Food, Typed Supps

A citrus small enough to eat whole, peel included — and the peel is the sweet part.

Stage by stage

Intake (Whole fruit chewed): Peel, pith and pulp are chewed together — the sweetness is in the peel, the acid in the flesh.
Digestion (Sugar within a fibre matrix): A 9.4g sugar to 6.5g fibre ratio, held in intact cell walls, moderates the glycaemic response.
Absorption (Vitamin C taken up): Ascorbate absorbs via saturable transporters, so food-level doses are used efficiently.
Colon (Pectin fermented): Peel pectin reaches the colon and is fermented into short-chain fatty acids.

Time to effect

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

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, Gluten-free. Depends on the product: Keto, Low-FODMAP.

Satiety

240 on the satiety index, where white bread is 100 — very high. Modelled from the Holt et al. (1995) measurements.

Environmental footprint

1.1 kg CO2e and 199 litres of freshwater per kg, matched to "Other fruit" in Poore & Nemecek (2018), Science 360.

Cost band

Cheap — roughly £3 per kg, as a band midpoint rather than a price.

Key nutrients

Vitamin C
Dietary fibre
Vitamin A activity

Nutrition per 100g

Calories: 64
Protein: 1.9g
Carbohydrate: 9.4g
of which sugars: 9.4g
Fat: 0.9g
of which saturated: 0.2g
Fibre: 6.5g
Sodium: 10mg

Food vs. supplement

A vitamin C tablet supplies far more ascorbate than the fruit, but absorption is saturable so most of the excess is excreted. The fruit's real advantage is the pectin, flavonoids and peel oils that come with it.

Kitchen tip

Eat it whole and unpeeled. Peeling a cumquat leaves the sour pulp and discards the sweet part, which is the reverse of every other citrus.

Common myth

"A cumquat is just a miniature orange." In reality: The sweetness is in the peel and the acid in the flesh, the opposite arrangement to an orange. Because the peel is eaten, a cumquat carries roughly two to three times the fibre of an orange for similar energy.