山藥粉應用於煎鬆餅與杯蛋糕之製作與其烘焙性質

以台農二號塊莖經熱風乾燥處理之山藥粉為材料，探討山藥粉製作煎鬆餅和杯蛋糕之烘焙特性。熱風乾燥山藥經以1mm篩網孔徑之磨粉機磨粉後，其粒徑相較於低筋麵粉(蛋白質含量7.76%)小，而假密度則較高。在吸水性與吸附能力方面，山藥粉與小麥麵粉在相同的相對水蒸氣壓（水活性）下，山藥粉具有較高的水結合能力與水含量。在麵糊特性方面，山藥粉具有較高的麵糰和麵糊黏度，導致其麵糊延展性和膨脹率較低，因而以山藥粉替代低筋麵粉所製成的煎鬆餅，組織較為密實。在適當水含量下，山藥粉置換率從0 增加到100% 時，煎鬆餅假密度則由0.66 g/cm3 增加到0.72 g/cm3。當山藥粉置換量為40% 時，煎鬆餅的硬度由244g增加到354g，但是煎鬆餅假密度(0.66 - 0.69) 則未有顯著的增加。以多因子試驗設計，探討山藥粉、水、油與增稠劑在製作杯蛋糕的交互作用，由消費性的感官品評結果顯示，水、油和CMC (carboxymethyl cellulose)的比例為230、45和0.5% 時，搭配100 %的山藥粉所製作的杯蛋糕與低筋麵粉搭配水(135%)、油(35%) 和CMC (0.5%)的對照組最具有相似性，而山藥杯蛋糕假密度(0.50 g/cm)較高，硬度(122g)較低，口感有些微的乾燥與柔軟。

關鍵字

煎鬆餅；山藥；杯蛋糕

並列摘要

To understand the baking properties of hot-air dried yam flour, rhizomes of a popular yam cultivar Tai-Nong 2 were used as the ingredient to replace low-protein wheat flour for making pancake and cupcake. The hot-air dried yam flour ground by a disc mill with 1 mm screen opening had smaller particle size and higher bulk density than commercial low-protein (7.76%) wheat flour. Comparing to wheat flour, the yam flour was found to be more hydroscopic and absorbing more water than wheat flour which displayed in higher value of water-binding capacity and higher water content at same relative vapor pressure (or water activity). The yam flour also showed higher batter and paste viscosity values causing lower batter spreading and expansion. The replacing of yam flour caused a denser quality of pancake. The bulk density of pancake increased from 0.66 to 0.72 g/cm3, as yam flour replacing ratio from 0 to 100% at optimizing water content. For pancake making 40% replacing of yam flour was not significantly increased the bulk density (0.66 ~ 0.69) of pancake, although the hardness of pancake increased from 244 to 354g. The attempt was also made to make a cupcake with yam flour without blending with wheat flour or gluten using a factorial experimental design. Water, oil, and bulking agent (carboxymethyl cellulose, CMC) content were selected as major corresponding factors and were subjected to study their effects. The water, oil and CMC contents were optimized at 230, 45 and 0.5% of yam flour (as 100%) according to the acceptability of the sensory evaluation for cupcake, comparing to 135, 35 and 0.5% content for using wheat flour. The yam cupcake had similar acceptability score with the one made from wheat with higher bulk density (0.50 vs 0.45 g/cm3) and lower hardness (122 vs 139 g). Comparing to cupcakes made from wheat flour, the general mouth-feeling descriptions of those made from yam were slightly drier and softer.