BULLETIN No. 240 - OCTOBER, 1997

THE USE OF POTASSIUM BROMATE
By Theresa Cogswell, Kansas City, MO
Copyright 1997 by the American Society of Bakery Engineers

Bakers who use potassium bromate can strive for a non detectable residual in the finished baked product. An industry study conducted in 1993 and 1994 provided some indicators for the complex process of oxidation and the role of potassium bromate in that process. This applied exercise showed trends in the relationships among some process parameters in baking. I reported on this material at the ASBE Annual Conference in March of this year.

Lower bromate residues were associated with:

lower levels of added bromate

when less than 30 ppm of potassium bromate was added to the flour and dough combined;

added ascorbic acid

when 40 to 100 ppm of ascorbic acid was added to the dough;

added ferrous sulfate

when ferrous sulfate was added for enrichment rather than reduced iron;

bleached flour

when bleached flour was used rather than unbleached flour;

lower dough pH

when the pH of the dough was at 5.2 rather than 5.7;

longer fermentation time

when potassium bromate was added to roll dough and the fermentation time was five hours rather than two or three hours; and when potassium bromate was added to bread dough and the fermentation time was at least three hours;

increased bake temperature

when bread was baked at 221 degrees centigrade (430 degrees Fahrenheit) rather than at 193 degrees centigrade (380 degrees Fahrenheit);

increased bake time

when bread was baked for longer than 22 minutes; and when rolls were baked for twelve minutes rather than eight minutes.

Quality control is critical when using potassium bromate. How much potassium bromate is used in a formulation will change for many reasons but one obvious example is a change in flour quality. If the flour quality changes and has a lower tolerance for the current formulation and machinability, then processing changes to accommodate that flour must be implemented. These changes may include fermentation time changes and the amount of potassium bromate used, as well as, changes to the amounts of other oxidizers or dough conditioners.

Residual potassium bromate in the finished product indicates that the potassium bromate did not function to improve the product and that the money spent on the ingredient was wasted. Some bakers have a particularly difficult time with potassium bromate in the form of tablets. Special attention is needed to make sure that the tablets are completely dissolved and mixed evenly through the dough.

The complex interaction of new enzyme mixtures and standard doughs using potassium bromate has not been studied but bakers who use potassium bromate may want to be cautious when adding these new products by having some understanding of what is in them and the purpose of the mixture.

A test methodology to measure potassium bromate residues in finished baked products will be published in the November/December issue of Food Additives and Contaminants. Bakers will be able to run this test in their own laboratory or through a commercial laboratory and maintain good quality control of their formulation.

The Food and Drug Administration requires that if potassium bromate is used, potassium bromate appear in the list of ingredients.