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Chemical and physical modification of dough by lipase addition. J. B. SOE (1), N. M. Barfod (1), and
C. H. Poulsen (1). (1) Danisco Cultor, Brabrand, DK 8220, Denmark.
Lipases (EC 3.1.1.3) can be defined as carboxyl-esterases which
catalyse the hydrolysis of long chain acylglycerols resulting in glycerol and free fatty acids. They are well
known enzymes, but have not until now been widely used in bakery applications. Recent studies, however,
have shown very interesting effects by using certain pure lipases in bakery products. The substrate for
lipases in wheat flour is 2-3% endogenous wheat lipids, which are a complex mixture of polar and
non-polar lipids. Previous studies of fractionating wheat lipids have shown that polar lipids have a positive
effect on baking performance, while the non-polar fraction is detrimental. The purpose of this study was to
follow the modification of wheat lipids by adding different types of lipases to dough. The effect of lipase on
non-polar lipids and polar lipids respectively was followed by extraction of lipids from dough. The
extracted lipids were then analysed by GLC, HPLC and spectrophotometric methods. The effect of lipase
on the lipid distribution in dough was followed by ultra centrifuge fractionation of the dough into a liquid
phase, a gel phase, a gluten phase and a starch phase followed by isolation and analysis of wheat lipid in
each fraction. The effect on physical properties by lipase modification of wheat lipids was evaluated by
surface tension measurements, rheological measurements and baking tests.
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