View source for Pyruvate scale

{{Short description|Measure of pungency in onions and garlic}}
{{Refimprove|date=May 2017}}The '''pyruvate scale''' measures pungency in [[onions]] and [[garlic]] with units of [[Mole (unit)|μmol]]/g<sub>fw</sub> (micromoles per gram fresh weight).<ref>{{cite web|title=Spring 2001 Commercial Vegetable Variety Trials|url=http://aurora.auburn.edu/bitstream/handle/11200/963/0053REGI.pdf|accessdate=2011-06-21}}</ref> It is named after [[pyruvic acid]], the [[alpha-keto acid]] co-product created in the biochemical pathway that forms [[syn-Propanethial-S-oxide|''syn''-propanethial-''S''-oxide]], the main [[wikt:lachrymatory#Adjective|lachrymatory]] agent in onions.

== Examples ==
[[File:2022072802 Gemuesezwiebel nach links gekippt 2022.jpg|thumb|A brown onion]]
The standard onion{{which?|date=June 2025}} has an eight rating, while "[[sweet onion]]s" have a two or three rating on the scale. The lower the score or scale the more "sweet" the onions are rated. Anything less than five is considered a sweet onion. The [[Vidalia onion]] variety is considered sweet and must have a score of 5.0 μmol/g<sub>fw</sub> or less.{{Citation needed|date=February 2007}} The HoneySweet brand onion is claimed to consistently rate with a pungency level of 3.5 or less.<ref>{{cite news |title=HoneySweet key to J&D onion program success |url=https://theproducenews.com/honeysweet-key-jd-onion-program-success |access-date=26 May 2024 |date=March 14, 2018}}</ref>

The Supasweet onion (usually grown in [[Lincolnshire]], [[England]]) registers 1.5 to 2 on the scale. A standard brown onion is usually in the range of 6–7 out of 10.

== Influential factors ==
Soil type, rain, and sunlight affect the pungency in onions and garlic and, therefore, their score on the pyruvate scale.

== See also ==

* {{annotated link|Scoville scale}}

==References==
{{Reflist}}

== External links ==
{{Portal|Food}}
* [https://www.ams.usda.gov/about-ams/programs-offices/national-organic-program The National Organic Program] — by the [[USDA]]{{Failed verification|date=January 2011}}

[[Category:Scales]]


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