Red onion

Red onions (Allium cepa var. aggregatum) are a variety of onion known for their purplish-red skin and flesh. They are a bulb vegetable grown from seed or sets and are cultivated worldwide, including in the UK. Red onions are typically harvested when mature and can be stored for several months.

Red onions are used as a flavouring ingredient in a wide variety of savoury dishes, both in home cooking and in manufactured foods. Their pungent, slightly sweet flavour adds depth and character to meals. They are commonly found in ready meals, sauces, marinades, and stuffing mixes.

Red onions are a whole food and not a food additive, so they do not have an E-number or require authorisation on the Register of Food Additive Authorisations. They are a source of fibre and various phytonutrients, including anthocyanins, which give them their red colour. While research suggests potential health benefits associated with diets rich in vegetables like red onions, no specific health claims are made by UK regulatory bodies for their consumption at typical dietary levels. Evidence on the specific health effects of compounds found in red onions is ongoing.