Studies on the lipids of flour. III Lipid binding in breadmaking

The proportions of easily extractable (free) lipid and residual bound lipid in dough and bread prepared by three different methods were determined and compared with the proportions of free and bound lipids present in the separate ingredients. Lipid binding increased during mixing to an extent dependent on the rate of dough development employed. The increase in bound lipid observed during dough mixing was due mainly to non‐selective binding of the available triglycerides. Diglycerides and free fatty acids were bound in preference to sterol esters and hydrocarbons, while the selective binding of polyunsaturated polar lipid represented only a small proportion of the observed lipid binding. After baking, the binding of polyunsaturated polar lipid accounted for half the observed increase in bound lipid, which may indicate that such lipids are of much greater significance in understanding the behaviour of bread in the oven than has been suspected hitherto. Nevertheless, this selectively bound polar lipid represents only a small proportion of the total bound lipid existing in dough and bread and is therefore not sufficient to affect significantly the overall fatty acid composition of either the total bound lipid or the remaining free lipid. It would appear that the presence of linoleic acid in a lipid is not sufficient in itself to ensure preferential binding during breadmaking.