Onions, raw
Whole food · Vegetables and Vegetable Products
Photo: Wikipedia
A raw onion is a pungent, crisp bulb with layered, translucent flesh that delivers a sharp, sulfuric bite and a surprising sweetness once chewed. Nutritionally, it's a low-calorie, high-fiber vegetable that provides a notable dose of vitamin C and antioxidants like quercetin.
💚 Why it's loved
People love raw onions for their powerful, sharp flavor and satisfying crunch that can instantly elevate a simple sandwich, salad, or salsa. Their versatility is unmatched, serving as a foundational aromatic in countless global cuisines.
⚠️ Watch-outs & how to enjoy it better
The strong compounds that give onions their flavor can cause digestive discomfort (like bloating or heartburn) for some and are notorious for causing bad breath. To counteract, try using milder varieties like sweet onions, finely dicing them, or pairing them with acidic ingredients like lemon juice or vinegar.
Key benefits
- Rich in antioxidants, particularly quercetin.
- Good source of prebiotic fiber to support gut health.
- Provides vitamin C for immune function.
- Low in calories and fat, adding volume and flavor to meals.
🍽️ Popular dishes
🌍 Where it's eaten
💡 Did you know?
Ancient Egyptian workers building the pyramids were reportedly given raw onions to eat daily, believing they provided stamina and warded off illnesses.
Full nutrition (scales with serving)
| Water | 89.1 g |
| Energy | 40.0 kcal |
| Energy | 166 kj |
| Protein | 1.1 g |
| Total lipid (fat) | 0.10 g |
| Ash | 0.35 g |
| Carbohydrate, by difference | 9.3 g |
| Fiber, total dietary | 1.7 g |
| Total Sugars | 4.2 g |
| Sucrose | 0.99 g |
| Glucose | 2.0 g |
| Fructose | 1.3 g |
| Lactose | 0.00 g |
| Maltose | 0.00 g |
| Galactose | 0.00 g |
| Starch | 0.00 g |
| Calcium, Ca | 23.0 mg |
| Iron, Fe | 0.21 mg |
| Magnesium, Mg | 10.0 mg |
| Phosphorus, P | 29.0 mg |
| Potassium, K | 146 mg |
| Sodium, Na | 4.0 mg |
| Zinc, Zn | 0.17 mg |
| Copper, Cu | 0.04 mg |
| Manganese, Mn | 0.13 mg |
| Selenium, Se | 0.50 ug |
| Fluoride, F | 1.1 ug |
| Vitamin C, total ascorbic acid | 7.4 mg |
| Thiamin | 0.05 mg |
| Riboflavin | 0.03 mg |
| Niacin | 0.12 mg |
| Pantothenic acid | 0.12 mg |
| Vitamin B-6 | 0.12 mg |
| Folate, total | 19.0 ug |
| Folic acid | 0.00 ug |
| Folate, food | 19.0 ug |
| Folate, DFE | 19.0 ug |
| Choline, total | 6.1 mg |
| Betaine | 0.10 mg |
| Vitamin B-12 | 0.00 ug |
| Vitamin B-12, added | 0.00 ug |
| Vitamin A, RAE | 0.00 ug |
| Retinol | 0.00 ug |
| Carotene, beta | 1.0 ug |
| Carotene, alpha | 0.00 ug |
| Cryptoxanthin, beta | 0.00 ug |
| Vitamin A, IU | 2.0 iu |
| Lycopene | 0.00 ug |
| Lutein + zeaxanthin | 4.0 ug |
| Vitamin E (alpha-tocopherol) | 0.02 mg |
| Vitamin E, added | 0.00 mg |
| Tocopherol, beta | 0.00 mg |
| Tocopherol, gamma | 0.00 mg |
| Tocopherol, delta | 0.00 mg |
| Tocotrienol, alpha | 0.04 mg |
| Tocotrienol, beta | 0.00 mg |
| Tocotrienol, gamma | 0.00 mg |
| Tocotrienol, delta | 0.00 mg |
| Vitamin D (D2 + D3), International Units | 0.00 iu |
| Vitamin D (D2 + D3) | 0.00 ug |
| Vitamin K (phylloquinone) | 0.40 ug |
| Vitamin K (Dihydrophylloquinone) | 0.00 ug |
| Fatty acids, total saturated | 0.04 g |
| SFA 4:0 | 0.00 g |
| SFA 6:0 | 0.00 g |
| SFA 8:0 | 0.00 g |
| SFA 10:0 | 0.00 g |
| SFA 12:0 | 0.00 g |
| SFA 14:0 | 0.00 g |
| SFA 15:0 | 0.00 g |
| SFA 16:0 | 0.03 g |
| SFA 17:0 | 0.00 g |
| SFA 18:0 | 0.00 g |
| SFA 20:0 | 0.00 g |
| SFA 22:0 | 0.00 g |
| SFA 24:0 | 0.00 g |
| Fatty acids, total monounsaturated | 0.01 g |
| MUFA 14:1 | 0.00 g |
| MUFA 15:1 | 0.00 g |
| MUFA 16:1 | 0.00 g |
| MUFA 17:1 | 0.00 g |
| MUFA 18:1 | 0.01 g |
| MUFA 20:1 | 0.00 g |
| MUFA 22:1 | 0.00 g |
| Fatty acids, total polyunsaturated | 0.02 g |
| PUFA 18:2 | 0.01 g |
| PUFA 18:3 | 0.00 g |
| PUFA 18:4 | 0.00 g |
| PUFA 20:2 n-6 c,c | 0.00 g |
| PUFA 20:3 | 0.00 g |
| PUFA 20:4 | 0.00 g |
| PUFA 20:5 n-3 (EPA) | 0.00 g |
| PUFA 22:5 n-3 (DPA) | 0.00 g |
| PUFA 22:6 n-3 (DHA) | 0.00 g |
| Fatty acids, total trans | 0.00 g |
| Cholesterol | 0.00 mg |
| Phytosterols | 15.0 mg |
| Tryptophan | 0.01 g |
| Threonine | 0.02 g |
| Isoleucine | 0.01 g |
| Leucine | 0.03 g |
| Lysine | 0.04 g |
| Methionine | 0.00 g |
| Cystine | 0.00 g |
| Phenylalanine | 0.03 g |
| Tyrosine | 0.01 g |
| Valine | 0.02 g |
| Arginine | 0.10 g |
| Histidine | 0.01 g |
| Alanine | 0.02 g |
| Aspartic acid | 0.09 g |
| Glutamic acid | 0.26 g |
| Glycine | 0.03 g |
| Proline | 0.01 g |
| Serine | 0.02 g |
| Alcohol, ethyl | 0.00 g |
| Caffeine | 0.00 mg |
| Theobromine | 0.00 mg |
FAQ
How can I reduce the eye-watering effect when cutting raw onions?
Chill the onion in the refrigerator for 30 minutes before cutting, or cut it under cold running water. Using a very sharp knife also helps by cleanly slicing the cells instead of crushing them, which releases fewer irritating compounds.
Are the green sprouts in an onion safe to eat?
Yes, the green sprouts are safe but may have a slightly more bitter or grassy flavor. They are not toxic, unlike sprouted potatoes.
What's the best way to store raw onions to make them last?
Store whole, unpeeled onions in a cool, dark, well-ventilated place like a pantry or cellar. Keep them away from potatoes, as they emit gases that can cause each other to spoil faster. Once cut, wrap the unused portion tightly and refrigerate for up to a week.