富含黏質是山藥塊莖的特徵，在組成上為蛋白質、醣蛋白與多醣的混合物。台農二號山藥栽培種以乾重計算含有7.7%的黏質，經分離冷凍乾燥的黏質經復水可再產生具有黏稠性的液體，此黏質液體於濃度為0.1%即有乳化與起泡性質。其油水乳化屬於油滴在水中的型式，使用等量黃豆油與水溶液進行乳化，0.1與0.5%黏質溶液的乳化安定性分別為59.7與78.1%，而其黏質溶液乳化油滴的容積平均直徑分別為57.6與19.4μm。0.5%黏質的油水乳化物為軟質乳油質地的剪稀半固體。0.1與0.5%黏質溶液的蛋白質吸附量分別認5.1與6.9mg/m2。1%山藥凍乾粉懸浮液具有泡沫安定性，其泡沫消失半衰期間高於120分鐘。
Rich in mucilage is one of characteristics of yam (Dioscorea) rhizomes. The mucilage of yam is a mixture of proteins, glycoproteins and polysaccharides. Tubers of the cultivar Tai-Nung 2 contain about 7.7% of mucilage in its dry weight. Separated and freeze-dried mucilage could be re-hydrated, resulting in a viscous solution. The mucilage solution exhibits emulsion and foam-forming ability in a concentration as tow as 0.1%. The emulsion was an oil-in-water type. The values of emulsion stability of 0.1 and 0.5% mucilage solution with equal amount of soybean oil were 59.7 and 78.1%, respectively. The mean volume diameters of oil-droplets were 57.6 and 19.4 pm for 0.1 and 0.5% mucilage solution, respectively. The emulsion of 0.5% mucilage showed a soft creamy texture and was a thixotropic semisolid. The protein-loads of the emulsion were 5.1 and 6.9 mg/m2 for 0.1 and 0.5% mucilage solution, respectively. The 50% drain time for foam of 1% freeze-dried yam flour suspension was more than 120 mm indicating a stable foaming capability.
