The Effect of Antioxidants on Flaxseed Stability in Yeast Bread

Abstract

The antioxidants BHA, BHT, and ascorbic acid were added to flaxmeal breads to prevent rancidity. Six types of yeast leavened breads were evaluated: control (100% bread flour), flaxmeal (15%) bread, and flaxmeal (15%) bread that contained 0.01% respectively of BHA, BHT, BHA and BHT, and ascorbic acid. Vital wheat gluten was added in all the flaxmeal breads. Chemical, objective and sensory tests were used to evaluate the breads. The crumb texture of all the experimental breads was significantly softer (p¡à 0.05) than the control breads, but the control breads were significantly moister (p¡à 0.05) than the flaxmeal breads that contained BHA and BHT, separately. No significant differences (p>0.05) were found in loaf volume of the control bread and the experimental breads. The crumb color of the experimental breads was significantly darker (p<0.0001) due to the incorporation of flaxmeal. The acid value of the flaxmeal breads was significantly higher (p¡à 0.05) than the control breads. No significant differences (p>0.05) were found in peroxide values between the control breads and experimental breads after eight weeks. The QDA sensory tests showed that breads containing BHA or in combination with BHT were moister, chewier and had the least noticeable stale taste when compared to the control breads. Ascorbic acid was not as effective as BHA or a combination of BHA and BHT in preventing lipid oxidation, but produced the softest bread. This study showed that flaxmeal breads made with BHA and BHT provided the best protection against lipid oxidation and produced a moist and chewy bread.