ENZYME-RESISTANT STARCH .3. THE QUALITY OF STRAIGHT-DOUGH BREAD CONTAINING VARYING LEVELS OF ENZYME-RESISTANT STARCH

Breads with varying levels of enzyme-resistant starch (RS) were obtain ed by replacing 24% of wheat flour (RS content 14.5%) with 4% vital wh eat gluten and 20% of one of the following: corn starch (CS), high-amy lose corn starch (HA), or extruded retrograded high-amylose corn starc h (ERHA). RS levels were 44.1, 83.2, and 29.5%, respectively. Breads w ere produced by the Finney (1984) procedure (100.00 g of flour or 76.0 0g of flour, 4.00 g of gluten, and 20.00 g of starch). All had excelle nt taste and shelf life, except for the CS breads. RS levels of bread were lower than could be predicted from the analytical data of the sta rting materials, which shows that some RS destruction occurs in the br eadmaking process. Thus, one day after baking, the RS content of bread s containing wheat flour, CS, HA, and ERHA was 0.0, 0.4, 7.7, and 8.4% , respectively. The latter breads showed the presence of retrograded a mylose or resistant granules. After seven days of storage, the RS leve ls had increased to 4.0, 4.4, 10.2, and 11.0%, respectively. Different ial scanning calorimetry measurements confirmed that the increase can probably be ascribed at least in part, to increases in the levels of r etrograded amylopectin. Bread volumes were 663.9, 654.3, 655.9, and 62 1.5 ml, respectively. The softest breads were those produced with ERHA ; the least soft ones were those with CS; the breads with wheat flour and HA had intermediate levels of softness.