Food-chemical studies on adzuki seed coat and color development of adzuki paste.

红小豆，Vigna angularis，是日本最受欢迎的豆类之一。然而，种皮的色素仍不清楚。此外，红木果皮和浆糊之间的颜色差异仍然不清楚，浆糊的颜色比种皮的颜色更略带紫色。本研究试图从红木种皮中分离出紫色色素，并对一种糊剂的紫色色泽变化进行了分析。通过对种子种皮提取液的分析，发现了两个新的紫色色素峰。经Amberlite XAD-7柱纯化，然后经Toyota opearl HW-40凝胶过滤柱纯化，得到紫色色素。在提取液中还鉴定出了槲皮素。提取糊剂生产过程中的几个样品，并用反相高效液相色谱对样品进行分析。在沙拉什-安中检测到两种紫色色素，这表明种皮中的色素在烘烤过程中必须转移到AN糊中。通过Shibu-kiri过程，从红色到深棕色的POW酚被去除，然后糊状物的颜色可能会变成紫色。

Red adzuki bean, Vigna angularis, is one of the most popular legumes in Japan. However the pigment of the seed coat is still unknown. Furthermore, the color difference between the adzuki peel and an paste; the color of an paste showed more purplish color than that of the seed coat, is still unclear. In this study we tried to isolate purple pigments from adzuki seed coat and analyzed the purple color development of an paste.We found two new peaks of purple pigments in the extract of seed coat by ODS-HPLC analysis. By purification with an Amberlite XAD-7 column, followed by a Toyopearl HW-40 gel filtration column the purple pigments were obtained. In the extract quercetin was also identified.Several samples in the manufacturing process of an paste were extracted and analyzed with ODS HPLC. In sarashi-an the two purple pigments were detected indicating that the pigments in seed coat must be transferred to the an paste during cocking process. By shibu-kiri process red to dark brown colored poWphenols were removed, then the color of an paste might be turned purple.