Onion
Overview
Onion ‘Allium Cepa’ is a perennial herb with stem & leaves above soil, and the bulb, which is widely consumed, under the soil. Onions were first domesticated in Near-East Asia and Central Asia around 7,000 years ago and its use rapidly spread around Eurasia. Onions played a major role in the culinary life of Ancient Egypt, Greece, and China, and the scientific taxon or name ‘Allium’ is likely derived from the Celtic word for ‘pungent’ [Block, 1985] 🔗. The use of Onion in present day cuisine is now widespread across the world, including in Australia [Australian Onions - The Onion Report, 2024]🔗.
The four major varieties of fresh-produce onions sold and consumed in the Australian marketplace are the ‘Brown’ (or ‘Yellow’) Onion (79%), the ‘Red’ Onion (19%), the ‘White’ Onion (1%), and ‘Shallots’ (or ‘Scallions’) (1%). ‘Sweet’ Onion, a type of Brown Onion is also produced in Australia [Horticulture Innovation Australia, 2020] 🔗.
CHOOSING YOUR ONION
Onion growth, harvest, storage & cooking are known to have significant effects on its bioactive profile. On a cursory inspection, the way an onion smells (‘pungency’), and…
FOOD SAFETY & ALLERGEN INFORMATION
Onions are generally safe to consume, unless contaminated. Please consult an expert clinician or certified dietitian if you require specific health information tailored to your …
SEASONALITY IN AUSTRALIA
Brown onion, white onions & shallots are in season during Oct, Nov, Dec & Jan (Spring & Summer). Red onions are in season during Feb, Mar &…
NUTRITIONAL INFORMATION
The nutrient reference values (NRV) for the major types of onions, both raw and fried (with no added fat), listed in the following table are sourced from the…
STORAGE AND COOKING
After fresh harvest, the bioactive content of onion, including Quercetin steadily rises as onion cell walls slowly breakdown [Sharma & Lee, 2016]🔗. When stored at room temperature…
HEALTH CLAIMS FOR MAJOR BIOACTIVES
There is a great deal of variation in the presence, concentration, and bioavailability of these bioactives among the different types of onions [Slimestad, Fossen & Vågen,…
BIOACTIVES IN ONION
Onion is a known ‘super food’ with a multitude of beneficial health claims attached to it [Chakraborty et al., 2022]🔗. Specific and high-quality information including verifiable concentrations…
BIOACTIVE FOCUS: Cycloalliin & Ajoene (Organosulphurs)
Cycloalliin and Ajoene are bioactive organosulphur compounds found in onions and shallots. The bioactive potency of organosulphurs are broad, with a range of anti-cancer, cardioprotective, neuroprotective activities reported…
BIOACTIVE FOCUS: Quercetin (Polyphenol)
Quercetin aglycone (i.e., ‘glucose-free’) and its glycosides (i.e., ‘glucose-attached’) polyphenol plant-metabolite compounds are a very powerful family of antioxidants that occur in onion in large concentrations.…
BIOACTIVE FOCUS: Cyanidin (Anthocyanin)
Cyanidin (i.e., ‘glucose-free’) and its glycosides (i.e., ‘glucose-attached’) are bioactive anthocyanins. While anthocyanins are most abundantly found in berries of different types, anthocyanins including cyanidin are…
INTERESTING FACTS
CITATIONS
Adeyemo, A. E., Omoba, O. S., Olagunju, A. I., & Josiah, S. S. (2023). Assessment of nutritional values, phytochemical content, and antioxidant properties of Shallot (Allium ascalonicum L.) leaf…