Physical Properties of Cookie Prepared with Different Solid Fat Index and Fatty Acid Composition (Part 2)

Properties of Oil Influencing on the Shortness of Cookies

Abstract

Properties of oil influencing on the shortness of cookies were examined. We prepared a series of cookies containing the oils with different physico-chemical properties, and examined the relationship between lipophilic properties of oil to flour components and the shortness of cookies. The state of oil in the structures of dough as well as in cookie were compared in a electron microscope observation at the same time.
(1) Starch oil-binding capacity did not vary with the kind of oil used.
(2) Gluten oil-binding capacity varied with the kind of oil and depended on the iodine value of oil.
(3) According to the multi-regression analysis between apparent fracture energy (Y), the solid fat index (SFI) (X₁), gluten oil-binding capacity (X₂) and saponification value (X₃) of oil, we obtained following equation : Y= 0.126X₁- 12.123X₂-0.018X₃+ 5.640. It's contribution ratio was 99.6%. So it became evident that cookie had a smaller apparent fracture energy with a lower SFI and a higher gluten oil-binding capacity of oil.
(4) In the dough and cookie, oil formed a continuous phase and covered over starch granules. But, the level of covering varied with the kind of oil, and were reflected well in the shortness of cookie.
(5) The use of oil in liquid state brought a lower fracture energy of cookie because of making a porus structure.
(6) The states of film network likely derived from gluten in the cookie related to the SFI of oil used.