February 26/Science Letter -- "The effect of rye flour extraction rates and baking on thiamine and riboflavin content, and antioxidant capacity of traditional rye bread were studied and compared with white wheat flour. The content of thiamine was higher (10.9%) in rye dough formulated with dark rye flour (F-100%; extraction rate of 100%) than in rye dough formulated with brown rye flour (F-92%; extraction rate of 92%) that was similar to dough made with wheat flour," scientists in Olsztyn, Poland report.
"The riboflavin content in rye dough made from flour F-100% was also higher (16%) than in dough formulated with flour F-92%, and both provided larger riboflavin content than wheat dough. Baking led to reductions in thiamine of 56% for wheat bread and of 20% for both rye breads; however, this process caused only a 10% decrease in riboflavin for wheat bread and a 30% decrease for rye breads. Trolox equivalent antioxidant capacity, peroxyl radical scavenging capacity, DPPH radical scavenging activity, and Folin-Ciocalteu reducing capacity were higher in rye than in wheat dough and bread. Baking process produced slight changes in antioxidant activity, except for Superoxide Dismutase-like activity where a sharp decrease was observed. Our findings showed that rye breads are an important source of B vitamins and rye breads formulated with dark and brown flours showed better antioxidant properties than wheat bread," wrote C. Martinezvillaluenga and colleagues.
The researchers concluded, "Therefore, rye breads should be more widely recommended in human nutrition."
Martinezvillaluenga and colleagues published their study in the Journal of Food Science ("Effect of Flour Extraction Rate and Baking on Thiamine and Riboflavin Content and Antioxidant Capacity of Traditional Rye Bread." Journal of Food Science, 2009;74(1):C49-C55).
For more information, contact H. Zielinski, Polish Academy Science, Institute Animal Reproductive & Food Research, Division Food Science, Tuwima 10, POB 55, PL-10747 Olsztyn 5, Poland.
From the February 16, 2009, Prepared Foods E-dition