Ascorbic acid

Ascorbic acid, also known as vitamin C, is an essential nutrient found in citrus fruits and many vegetables. It plays a crucial role in flour standardization and improvement. Ascorbic acid enhances gas retention in doughs and increases the volume of baked products. In combination with naturally occurring enzymes in flour, it promotes the oxidative strengthening of gluten in the dough. To ensure optimal safety and reliability in the production process, ascorbic acid must have a precise particle size.

Ascorbic acid is commonly used as a wheat flour improver in bakery fermented products, helping to increase bread volume and improving tolerance to variable processing conditions, such as changes in dough temperature and flour modification. When used alongside dough-strengthening enzymes like lipase, amylase, and xylanase, it is also integral to formulations for chemical-free products. One of ascorbic acid’s key functions in bread dough is stabilizing the gluten network, which results in bread with larger volume, a finer texture, and more uniform crumb.

Unlike traditional oxidizing agents like potassium bromate, azodicarbonamide (ADA), and calcium peroxide, the action of ascorbic acid is dependent on external factors. To act as an oxidizing agent, ascorbic acid requires oxygen and the presence of naturally occurring enzymes in cereal grains. Although ascorbic acid is a strong antioxidant and reducing agent in food systems, it is converted to its dehydrogenated form in the presence of oxygen and ascorbic acid oxidase, an enzyme found in wheat flour. The oxidized form of ascorbic acid participates in oxidation reactions during flour and water mixing, such as the SS/SH exchange between cysteine residues of gluten-forming proteins.

This oxidation of thiol groups creates disulfide bonds between proteins, resulting in gluten cross-linking and polymerization, which strengthens the gluten network. As a result, the dough can retain more gas, has greater elasticity, and is more resistant during rolling and shaping. The flour absorbs more water, improving the dough’s rheological properties and reducing its stickiness.