lemon and lime slices

Ascorbic acid, or vitamin C, is an essential nutrient found in citrus fruits.

Ascorbic Acid

Also Known as Vitamin C


What is Ascorbic Acid?

Ascorbic acid, also known as vitamin C, is an essential nutrient found in citrus fruits. It used as a bread improver and its addition to dough causes an increase in loaf volume and an improvement in crumb structure.1

In baking, it is used as an oxidizing agent for dough mixing.  Frequently used in clean label systems, it helps replace ADA and other dough conditioners.


Ascorbic acid was discovered in the late 1920s by Albert Von Szent Györgyi.2 He was awarded the Nobel Prize in 1937 for his discovery.2 At that time it was a cure for scurvy, which was caused by a dietary deficiency in fresh fruit and vegetables. In 1935 the use of ascorbic acid as a dough improver was observed by Jorgensen.1 The use of this acid in bread dough in the range of 20-30 mg/ kg of flour increased bread volume by 20%.1  It may be from natural or synthetic sources.

Chemical structure, ascorbic acid, vitamin C, baking ingredient, acid

Chemical structure of ascorbic acid.


Ascorbic acid is required for the biosynthesis of collagen, L-carnitine, and certain neurotransmitters; vitamin C is also involved in protein metabolism.3 The RDA for adults is 75-90 milligrams a day. When used in baking, it bakes out fully so there is no ascorbic acid retained in the finished baked good.


In breads, ascorbic acid improves the ability of the dough to retain gas and yields bread with a finer crumb cell structure.4 This results in bread crumb that is softer to touch yet has the resilience to recover much of its original shape after compression.4

It performs the following functions in baking:4

  • Improved product volume
  • Improved cell structure
  • Improved crumb softness
  • Extended product shelf life
  • Increased mold-free shelf life


Ascorbic acid works best in short-fermented products up to 2 hours. Its use in the sponge part of a sponge and dough process is not recommended. Levels used in bulk fermentation should be low and limited to not more than 15-20 ppm flour weight (0.15-0.20 g to 10 kg flour).4  

FDA Regulations

Ascorbic acid is generally regarded as safe (GRAS) by the FDA when used in accordance with good manufacturing practices.5


  1. Grosch W., Wieser H. Redox reactions in wheat dough as affected by ascorbic acid. Journal of Cereal Science 29.1 (1999):1-16.
  2. Arrigoni O., De Tullio M.C. Ascorbic acid: much more than just an antioxidant. Biochimica et Biophysica Acta (BBA) – General Subjects 1569.1 (2002):1-9.
  3. US Department of Health and Human Services Office of Dietary Supplements – Vitamin C. NIH Office of Dietary Supplements, https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/.  Accessed 08 August 2017.
  4. Cauvain S.P. What are the functions of ascorbic acid in breadmaking? Baking Problems Solved, 1st ed., Woodhead, 2001, pp. 136–137.
  5. US Food and Drug Administration. CFR – Code of Federal Regulations Title 21. Accessdata.fda.gov, www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfCFR/CFRSearch.cfm?fr=182.3013. Accessed 08 August 2017.