Chih-Hsien Wang, Ming-Jane Chen, Chin-Yin Tseng, Kuo-Min Wei and Wenlung Chen
The structure of functional compositions isolated from D. purpurea (Cultivar of Ming-Chien) was characterized by FT-Raman. After serial isolation and purification, functional compositions of D. purpurea including allantoin, anthocyanin, β-carotene, lecithin, and dioscorin were identified. The shiny crystalline of allantoin was stable enough to tolerate with dramatic change in pH as evidenced by the consistency of FT-Raman spectra. Spectroscopic results indicated that anthocyanin was responsible for the distinguished purple coloration in D. purpurea. A very small quantity of egg-yolklike compound extracted by hexane was identified as a mixture of β-carotene and lecithin Raman stretching of amide I at 1668 cm-1 and amide III at 1241 cm-1 indicated that the structure of dioscorin, the major storage protein in yams, was mostly in anti-parallel β−sheet. And a slightly conformational difference in the protein structure was detected when the protein was treated with acetone and alcohol, respectively