RESISTANT STARCH FORMATION IN BREAD AS INFLUENCED BY CHOICE OF INGREDIENTS OR BAKING CONDITIONS

The formation of resistant starch (RS) in bread products was evaluated in vitro in relation to the processing conditions. The impact of the particular baking conditions applied to pumpernickel bread was investi gated as well as the presence of malt and sourdough acids, commonly pr esent in such bread. Also studied was the potential effect of includin g wholemeal barley from a high-amylose genotype. In some bread, the ra te of hydrolysis of the potentially available starch fraction was eval uated by an in vitro procedure. A low-temperature, long-time baked pro duct (20 h at 120 degrees C) contained significantly higher amounts of RS (5.4%, starch basis) than a corresponding ordinary baked bread (40 min at 200 degrees C) (3.0%, starch basis). Addition of lactic acid i ncreased RS recovery further (6.6% starch basis), whereas malt had no impact on RS yield. The highest level of RS was noted in a long-time b aked bread based on high-amylose barley flour (7.7%, starch basis). In contrast to all other products, this bread also displayed a lowered r ate of amylolysis of the non-RS fraction (hydrolysis rate index = 68). It is concluded that exchanging ordinary baking conditions for pumper nickel baking, particularly in the presence of certain organic acids, may substantially increase the RS content. Copyright (C) 1996 Elsevier Science Ltd