Abstract
Effects of sodium chloride on the physical properties of cookie dough and cookie were examined. The two procedures (F-procedure and W-procedure) were used to preparing dough.
Sodium chloride softened dough, but made less adhesive so that there was a tendency to make it easier to extend and to form dough. Cookies were baked in a form of large spread and its expansion rate decreased markedly by the addition of sodium chloride. The addition of sodium chloride made cookies harder, but on the contrary, the increase in the sodium chloride concentration lowered the fracture resistance. The lipophilicity between lipids and gluten, and the amount of lipids extracted from cookies changed by the addition of sodium chloride, but it did not correlated with the change in the fracture resistance of cookies. The degree of the effects of sodium chloride on physical parameters of dough and cookie in W-procedure were larger than those in Fprocedure. This fact suggested that the effects of sodium chloride on protein contributed mainly to the changes in physical properties of dough and cookie. In the cookies with sodium chloride, the aggregates supposed to be mainly composed of proteins were observed from the electron microscope. Proteins aggregate by the action of sodium chloride, folding in starch particles together. Therefore we conclude that its structure becomes dense and it expands to less extent, and moreover, the fracture resistance increases. Because the more sodium chloride added, the larger the extent of protein aggregation becomes, the structure is made porous. Thus it becomes more easily broken at fracture.
