Do Yellow Onions Have Quercetin? (EXPLAINED)

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Does yellow onions have Quercetin?

Yellow onions, also called brown onions, are high in sulfur and have a very strong, almost spicy flavor profile. Generally considered more of a cooking onion than one to be eaten, raw, yellow onions are a culinary staple and an excellent way to add nutrition to various dishes. Our question is, do yellow onions have quercetin?

Quick Answer: Yes – Yellow onions do contain quercetin. Compared to other similar foods, their quercetin content is high.

Quercetin Content of Yellow Onions

Yellow onions contain 15mg/100g of quercetin and are rich in 13 vitamins and minerals.

Are Yellow Onions High in Quercetin?

Compared to other foods, yellow onions are very high in quercetin.

Let’s take a look at how they compare to 5 similar foods.

  • Red onions outstrip yellow onions offering more than double the quercetin content with 31mg/100g.
  • Sweet onions contain no quercetin at all.
  • Garlic only provides 1.74mg/100g of quercetin, giving yellow onions a seven-fold advantage.
  • Fennel bulbs are no competition for yellow onions containing only 0.23mg/100g of quercetin.
  • Horseradish root provides 0.28mg/100g of quercetin, 14.72mg/100g less than yellow onions.


National Library of Medicine “Waste streams in onion production: Bioactive compounds, quercetin and use of antimicrobial and antioxidative properties”:,25%20mg%20Trolox%20equivalents%20g-1and%20high%20antimicrobial%20activity. 

USDA Database for the Flavonoid Content of Selected Foods: