Baked foods a focus of F.D.A. acrylamide guidance
Nov. 15, 2013
by Josh Sosland
WASHINGTON — Baked foods, together with potatoes and coffee, are a centerpiece of new Food and Drug Administration guidance aimed at reducing acrylamide in the food supply.
The draft document, which will not be binding on manufacturers even when finalized, was issued by the Center for Food Safety and Applied Nutrition on Nov. 14.
While it has been longer than 10 years since scientists announced the discovery of acrylamide in a number of heated foods, the F.D.A. said much still remains to be learned about the subject. They suggested their findings and recommendations could be subject to change in the years ahead.
“Acrylamide reduction is an area of ongoing research, and some approaches discussed may be at a research stage rather than in general use,” the guidance said. “We recommend that manufacturers evaluate approaches that may be relevant to their particular products and consider adopting approaches, if feasible, that reduce acrylamide in their products.”
The guidance features several pages addressing ways to reduce acrylamide in grain-based foods, including bread, crackers and breakfast cereal.
Acrylamide forms in food from a chemical reaction between asparagine, an amino acid, and reducing sugars, such as glucose and fructose, the F.D.A. said. Part of what is known as a Maillard reaction, the process leads to color, flavor and aroma changes in cooked foods and occurs when cooking, frying or baking are done at moderate to high temperatures.
In the case of grain-based foods, it is the presence of asparagine “in excess” rather than reducing sugars that is a driver of acrylamide formation, the F.D.A. said. Between different cereals, asparagine content is highest in rye, followed by wheat, corn and oats, and then rice.
Among approaches suggested in the guidance for reducing acrylamide is the replacement of ammonium bicarbonate as a leavening agent in cookies and crackers. Citing advice from the Snack Food Association, the F.D.A. said using alternative leavening agents “is one of the most effective mitigation techniques in cookies for smaller member companies, due to reasonable costs and limited impact on quality.”
Such a limited impact on quality is not the case with all or even most of the F.D.A. advice. For example, the F.D.A. suggests using “asparaginase treatment” to help with acrylamide reduction but warns “dose, contact time, dough water content, pH and water chlorination are important considerations.”
Fortification of flour with 0.3% to 1% calcium carbonate or calcium chloride may be effective for reducing acrylamide, the approach would not be practical for makers of crackers.
Even though laboratory trials have shown the addition will reduce acrylamide content, “product quality has been poor,” the F.D.A. said.
Yeast and fermentation modifications may be helpful, the F.D.A. said.
“Modification to baking time and temperatures can result in lower acrylamide levels in baked foods, breakfast cereals, crispbreads and other cereal-based foods,” the F.D.A. said. “Another approach is to lower baking temperature during the final stages of cooking, when moisture levels are low and acrylamide formation is more likely.”
The guidance goes on to identify several potential drawbacks to these approaches, including slower production lines, lighter color, shorter shelf life and the need for recipe changes.
Discussing treatment of bread with amino acids, the F.D.A. said trials have offered promising results, including the addition to dough of amino acids such as cysteine and glycine.
“However excess cysteine in doughs can negatively affect bread structure and flavor,” the guidance said. “Glycine also may mitigate acrylamide when added to bread dough or applied as a spray to the surface of the dough prior to baking. However glycine in large amounts may reduce fermentation. Also, a glycine spray needed repeated applications and reduced acrylamide levels only about 15%.”
The cautions continued, “Researchers have not been able to mitigate glycine’s effects on color and taste, while also meeting requirements for moisture, texture and shelf life. Added proline and lysine also caused unacceptably bitter flavors.”
In their advice to consumers, the F.D.A. urges the adoption of a healthy eating plan consistent with the Dietary Guidelines for Americans, including an emphasis on “fruits, vegetables, whole grains and fat-free or low-fat milk and milk products.”
The challenges of reconciling their acrylamide guidance with the D.G.A. was evident in the advice to eat whole grains since the F.D.A. cited evidence whole wheat bread tends to be higher in acrylamide than white bread. The paradox was acknowledged in the guidance.
“Reducing whole grain content may also reduce acrylamide, but F.D.A. does not recommend this approach given the benefits of whole grains,” the F.D.A. said.