Lowering sodium with leaveners, part 3
July 20, 2012
by Laurie Gorton
Sodium, potassium or ammonium bicarbonate — which will work best for your formulation? Here’s advice from Rob Berube, manager of technical service for Church and Dwight Co., Inc., Princeton, NJ, in an exclusive Q&A session.
Baking & Snack: How do chemical leavening ingredients help the formulator reduce the sodium content of baked foods and snacks? How does their use change the finished product’s sodium content?
Rob Berube: Sodium bicarbonate contains about 27.4% sodium. If sodium bicarbonate is used at 1% in a formula, it can account for 2,740 ppm of sodium. Potassium and ammonium bicarbonate provide options to reduce or eliminate this sodium contribution.
Are there sodium-bearing leavening ingredients that the formulator should consider retaining? What impact do they have on the finished product’s sodium numbers?
Potassium bicarbonate provides a “drop in” replacement performance profile with few exceptions, but there is a significant upcharge for the potassium analogue. Ammonium bicarbonate is far more versatile than commonly thought, but it does have limits. For some applications partial replacement of sodium bicarbonate is the optimal answer.
What should a formulator know about these materials and their usage levels? Are there limits to their use? How must they be labeled in the ingredient listing on packages?
Because of its higher molecular weight, 19% more potassium bicarbonate (compared with the replaced sodium bicarbonate) is required to deliver an equivalent amount of carbon dioxide. In completely neutralized systems, essentially no difference is seen in the physical characteristics, texture and taste of the substituted baked good. In systems where there is an excess of soda, potassium bicarbonate will produce a relatively darker color due to the marginally higher pH of its residual carbonate salt. Taste is not an issue as might be expected with other potassium salts.
Ammonium bicarbonate can be used at 94% of the amount of sodium bicarbonate replaced. Because it completely volatilizes at temperatures above 60°C, it can be used without a leavening acid, leaving no residual salt. However, when used in this manner, its use is limited to products with no more than 3 to 5% finished moisture. Higher moisture levels will cause ammonia to be retained, negatively impacting taste and odor. Because of the ammonia odor, ammonium bicarbonate is not suitable for dry mixes or refrigerated dough products.
When completely neutralized, however, ammonium bicarbonate can be used in products with higher finished moisture without negatively impacting product aesthetics.
If changing leavening ingredients, what factors must the formulator consider to ensure success with the new leavener?
Following the above guidelines should ensure success in complete or partial elimination of the sodium contribution from sodium bicarbonate. We are always available to provide technical assistance.
What chemical leavening ingredients does Church and Dwight offer for bakery and snack applications?
Sodium Bicarbonate USP Grades 1 and 2 are the workhorse products. Grade 1 is also available in a Treated Free Flowing version (TFF), and a “timed release” Tortilla Blend has been developed for perfect tortillas. Flow K Potassium Bicarbonate is a sodium-free option that provides the nutritional benefits of potassium. Ammonium Bicarbonate is another interesting sodium-free option.