Characterization of baking lipase substrate specificities for use in fine bakery goods

  • Contact:

    Prof. Dr. Katharina Scherf

  • Project Group:

    Charlotte Stemler, M.Sc.

  • Funding:

    BMWK, AiF 20771 N

  • Partner:


  • Startdate:

    01 October 2019

  • Enddate:

    31 December 2022

In Germany, fine bakery goods are defined as baked goods containing 90 parts of cereal flour products and at least 10 parts of fat and/or sugar. The use of flour improvers is common in bakery goods to enhance the baking quality of the flours and balance variabilities caused by environmental effects. Lipases belong to the carboxylesterhydrolases and may be subdivided into triacylglyceride (TAG) lipases, phospholipases and galactolipases. The use of exogenous lipases in baked goods yields doughs with lower stickiness and improved stability and elasticity. During baking, higher bread volumes are reached and the breads have lower staling rates caused by their softer and more homogeneous crumb texture. White wheat flour contains about 2 - 2.5% lipids, with TAG as major components (40%), followed by free fatty acids (FFA) and digalactosyldiglycerides with about 15% each and N-acyl-lysophosphatidylethanolamine with 8%. The aforementioned functional effects are primarily caused by partial hydrolysis of nonpolar TAG resulting in polar surface-active FFA and di- (DAG) and monoacylglycerides (MAG). In the presence of milk fat, e.g., butter in the recipe, short-chain fatty acids, such as butyric acid, can be released and cause a rancid off-flavor. While this contributes to the typical aroma of many cheeses, such an off-flavor is undesirable in fine bakery goods. The aim of this proposed project is the characterization of baking lipase substrate specificities for use in fine bakery goods. The project is based on the hypothesis that it is possible to identify lipases that have a favorable substrate specificity by releasing only minimal amounts of short-chain fatty acids responsible for the off-flavour, while ensuring the positive textural attributes during dough handling, baking and storage.