Vegetables Alliums Phytochemical data available 🇺🇸 USDA FDC 2025
✦ Quercetin ✦ Sulphur compounds ✦ Prebiotic fibre ✦ Low calorie

Yellow onions are the everyday cooking onion, with a stronger flavour than red or white types. They provide quercetin, sulphur compounds, prebiotic fibres and small amounts of vitamin C.

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Preparation note

Slow cooking develops sweetness but reduces vitamin C and some sulphur compounds; using both raw and cooked in a dish keeps a balance.

Sources: CoFID 2021

Macronutrients per 100g

159
kJ
Energy
0.83
g
Protein
6.71
g
Carbs
1.33
g
Fibre
0.05
g
Fat
5.82
g
Sugars
0.00
g
Salt

Vitamins & Minerals

Nutrient Per 100g % Daily Value* Level
Potassium 182 mg 9%
Phosphorus 34.0 mg 5%
Calcium 15.0 mg 2%
Magnesium 9.00 mg 2%
Vitamin C 8.20 mg 10%
Iron 0.280 mg 2%
Zinc 0.200 mg 2%
Manganese 0.144 mg 7%
Copper 0.035 mg 4%
Selenium 0.000 µg 0%
Iodine 0.000 µg 0%
Glucose (dextrose) 2.31 g —
Fructose 1.91 g —
Sucrose 1.60 g —
Biotin (Vitamin B7) 0.000 µg 0%

* % Daily Value based on EU Nutrient Reference Values (NRVs). — indicates no EU NRV established.

Primary data source for this entry: USDA FoodData Central (FDC 2025). Values adjusted to UK measurement conventions before import: fibre converted from AOAC to NSP (×0.7); carbohydrate reported as available carbs (fibre excluded). Source record tag: USDA FDC 2025. Phytochemical data: USDA Flavonoid Database Release 3.3 (2018) and published analytical literature as indicated on each compound. All values are per 100g fresh weight unless stated. % Daily Values based on EU Nutrient Reference Values (NRVs) per Regulation (EU) No 1169/2011. Nutriofia is a research and information resource — nothing on this page constitutes medical advice. Page generated from Nutriofia database · Argarth Collective Ltd · Company No. 16864945.