In order to clarify the roll of the prime starch and starch tailing fraction of wheat flour on the physical properties of cookies, these two fractions were isolated from wheat flour and separately mixed with gluten, as so to get reconstituted flours. Cookies were prepared by using the reconstituted flours in place of wheat flour, and the physical properties of the cookies were evaluated.
Breaking test of the cookies showed that P (prime starch fraction) -cookie was soft but poor in shortness, while T (starch tailing fraction) -cookie was hard but good in shortness and crispness. P-cookie expanded crosswise. Its surface showed swelling shape and was uneven. Large voids were formed in its inside, resulting in a remarkably high expansion ratio. This rough porus structures causes the small fracturing stress and poor shortness of P-cookie. T-cookie expanded not in the horizontal direction but upward, and voids in its inside were small. As a result, both of spread factor and expansion ratio were low. S (starch fraction) -cookie had a proportional appearance, compared with the others. S-cookie was soft and possessed shortness. It was concluded that the favorable texture of cookie were given by coexistence of prime starch and starch tailing fractions.