Question

the polar lipids have positive effects in baking whilst non-polar lipids distinctly deleterious effects (mac ritchie 1984)."

Answer 1

Wheat flour lipid was separated into five fractions by selective elution from silica gel. The two earlier eluted fractions, which contained mainly non-polar components, depressed loaf volume when added to defatted flour. The three other fractions contained polar components and these maintained or increased loaf volume. The effects of the fractions as foam stabilizers paralleled their effects on loaf volume, supporting the theory that flour lipids exert their action in baking through their role as surfactants in stabilizing or destabilizing the gas bubble structure during expansion of the loaf. Evidence points to a classification of flour lipids into three groups according to their effects in baking. The polar galactolipids and phospholipids increase loaf volume, compounds of intermediate polarity depress loaf volume while the more non-polar compounds such as triglycerides have little effect in the absence of other lipids but have beneficial effects when other lipids are present. Thin-layer chromatography showed clear differences in composition between lipid extracts from wheat, rye and maize flours and these could be correlated with effects on the baking behaviour of defatted wheat flour.

Answer 2

Wheat flour lipid was separated into five fractions by selective elution from silica gel.


The two earlier eluted fractions, which contained mainly non-polar components, depressed loaf volume when added to defatted flour.


The three other fractions contained polar components and these maintained or increased loaf volume.



The effects of the fractions as foam stabilizers paralleled their effects on loaf volume, supporting the theory that flour lipids exert their action in baking through their role as surfactants in stabilizing or destabilizing the gas bubble structure during expansion of the loaf. Evidence points to a classification of flour lipids into three groups according to their effects in baking.



The polar galactolipids and phospholipids increase loaf volume, compounds of intermediate polarity depress loaf volume.


while the more non-polar compounds such as triglycerides have little effect in the absence of other lipids but have beneficial effects when other lipids are present.


Thin-layer chromatography showed clear differences in composition between lipid extracts from wheat, rye and maize flours and these could be correlated with effects on the baking behaviour of defatted wheat flour.