Optimization of Yam Semi Hard Biscuit Formula by Response Surface-principal Component Analysis

In order to broaden the application field of yam, the low gluten wheat flour and yam powder were used as raw materials to develop yam semi hard biscuit. Taking sensory score and texture as comprehensive evaluation indexes, the single factor experiment was carried out to study the effect of the amount of yam powder on the semi hard biscuit. On this basis, response surface and principal component analysis were used to optimize the formula of yam semi hard biscuit. The results showed that:according to flour (low gluten flour+yam powder) as 100%, the addition amount of yam was 28%, water 26.76%, olive oil 13.30%, phospholipid 0.76%, sugar 20%, salt 1.0%, sodium bicarbonate1.0% and ammonium bicarbonate 0.5%. The baking temperature:up was 170℃, down was 150℃ and the time was 12 min. Under this condition, the hardness of biscuit was (697.01±20.83) g, the flexibility was (0.292±0.018) mm, and the sensory score was 81.80±3.63.The texture of biscuits was better than that of blank biscuits, and biscuits had crispy tasty and uniform color with a unique yam flavor.