Reducing Agents In Baking

Baking is now one of the most popular pastimes and attracts great attention – it is justifiably a culinary skill. Baked goods such as bread, tortillas, cookies, crackers and pizza dough rely on gluten protein from wheat to provide a typical texture but not too much otherwise the product is so chewy it is impossible to eat. To control this, bakers add reducing agents which damage the gluten structures that form so that they become more elastic, more extensible and less hard. The shape of the product is also better retained, being less prone to shrinkage and curling. Incidentally, to produce a harder dough structure, oxidising agents are needed.

Reducing agents are often  used along with a slow oxidiser to generate the right texture and it’s a practice in use for over 30 years. They are added to bread mixes or ones with high protein flour. Where automation and high-speed processes are employed, these agents are needed to reduce mixing times and improve machinability of the dough so that it can be handled by special dough pumps. To meet the increasing demands for such high speed throughputs, the wheat growers and millers are selecting wheat varieties that produce doughs with greater strength but are less extensible.

The type of reducing agents available include:

1. Sulfites (sulphites)—commonly used in cookie and cracker production, require special label declaration in the U.S. if used at a level above 10 ppm.
2. Protein-based agents especially amino-acids such as L-cysteine, and now the most commonly used ingredient in bread, glutathione, a peptide which also contains cysteine, and claimed to be more effective, and inactivated yeast which provides a natural source of glutathione.
3. Ascorbic acid—used only in certain closed continuous mix systems and without the presence of oxygen because it functions as an oxidizing agent in the presence of oxygen. It is sometimes needed in conjunction with glutathione.