Developing a formulation decrease fat content of doughnuts

• Main Authors: Feng-Chen Yen, 顏鳳珍
• Other Authors: Chyi-Shen Lin
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/59102976001941976762

碩士 === 國立屏東科技大學 === 食品科學系 === 94 === Doughnut processed with various materials and methods can be classified into yeast fermented, cake, twist and French style puff crullers doughnuts. The frying stage caused significant amount of fat absorption made it a high calories food. The goal of this study is to develop a method of lowering dough fat content in yeast raised doughnut. The tested formulation is developed adding modified starch and food gum additives and water in oil-free dough to replace the 10% shortening in the traditional formulation. The dough is added with modified starch (PJ20, CH20, T4, G), food gum (carboxymethy1 cellulose, xanthan gum, pectin, guar gum). The tested dough with 5% modified starch and 5% water showed the softest texture and easy to handle. The formulation with 1% food gum and 9% water is also acceptable, the dough is soft and well-handled. Adding modified starch and food gum to replace the shortening in traditional formulation into the dough can lower oil uptake and increase water uptake. Without using shortening, the dough becomes less soft and with more viscosity, and doughnut showed less tender and with more surface shrinkage. Further adjusting the flour ratio, and 10-20% gluten-free tapioca starch, corn starch and protein-free wheat starch are added to replace medium flour. The flour ratio in the control sample is 70% bread flour and 30% medium flour. The acceptable dough formulation tested is 50% cake flour, 40% medium flour, and 10% protein-free wheat starch. It can improve doughnuts softness and reduced surface shrinkage. The oil available for frying doughnut are soybean oil, palm oil, mix vegetable oil. These frying oils did not significantly affect the doughnut qualities, including volume, color, fat, and moisture, oil absorptiveness of the paper, quality analysis, and sensory characteristics. The result showed that soybean oil is the best among them for the quality of doughnuts. Furthermore, the result of on the oil-free doughnut formulation showed that the carboxymethyl cellulose is the most acceptable for improving the quality of doughnuts.