Relationships between lipase-treated wheat lipid classes and their functional effects in wheat breadmaking

Fractionation of lipase-treated wheat lipids showed that polar lipase-reaction products were responsible for their positive functional effects in breadmaking. The results allowed the conclusion that an optimal baking lipase preferably hydrolyzes monogalactosyl diglycerides and N-acyl phosphatidyl ethanolamine, but has only moderate activity towards digalactosyl diglycerides. Synergistic effects of digalactosyl diglycerides and their products digalactosyl monoglycerides (molar proportion 1:1) provide even a greater bread volume increase. Reconstitution baking (defatted flour plus lipid or lipid fraction added) partly provided contradictory results. 100% polar lipase-treated lipids were less active than untreated polar dough lipids plus polar flour lipids. Combinations of non-polar and polar lipase-treated lipids were even more active than the polar ones alone. It appears that the polar reaction products of baking lipases need the presence of unmodified lipids or non-polar lipids to provide optimal functional effects. The present data suggests that synergistic effects between different lipid classes might play a key role in the mechanism of action of baking lipases.