EFFECTS OF CONVENTIONAL BAKING, MICROWAVE BAKING, AND STEAMING ON THE NUTRITIVE VALUE OF REGULAR AND FORTIFIED BREADS

摘要

ABSTRACTThe nutritive value of protein in regular and fortified breads was significantly affected by methods of baking. Rat‐feeding tests demonstrated that protein efficiency ratios (PERs) of breads were significantly improved and feed conversion ratios were reduced by substituting steaming or microwave baking for conventional baking. Lysine and other amino acids varied little among conventionally baked, microwave baked, and steamed breads. The significantly low PER of conventionally baked bread indicated that lysine became less available nutritionally with conventional baking than with either microwave baking or steaming. Lysine or soy fortification could effectively raise the PER of conventionally baked bread. Loaf volume and crumb qualities of conventionally baked bread were better than those of microwave‐baked or steamed bread. However, conventional baking produced a much darker brown crust and crumb than did microwave baking or steaming. The effect of heating, as shown by browning, on reducing the bread's nutritive value could be greatly minimized by replacing conventional baking with microwave baking or steam