Host: Japanese Sciety for Food Science and Technology
Name : The 72nd Annual Meeting of JSFST
Number : 72
Location : [in Japanese]
Date : August 27, 2025 - August 29, 2025
[Objective] The main use of azuki beans is to make bean paste, and it is said that bean paste made by with good ingredients and carefully processed by craftsmen will have a purple color. In recent years, Nagoya University has elucidated the structure and characteristics of the pigments contained in azuki beans1), and based on this knowledge, a new method for making bean paste that makes use of the purple pigment contained in azuki beans has been established2). In this study, we confirmed the purple coloring during the bean paste making process and confirmed the effectiveness of the new method by comparing it with commercially available sweetened bean paste.
[Method] The purple pigment contained in azuki beans is characterized by being poorly soluble in water and easily oxidized; a deaeration process was added during the new soaking to prevent oxidation of the pigment. To compare with commercially available sweetened bean paste under the same conditions, those were repeatedly washed with water to obtain unsweetened bean paste．
[Results] The new method produced bean paste with a characteristic purple colour with good reproducibility. A comparison of bean paste made using the new method with commercially available bean paste confirmed that the new method is an excellent method for producing azuki bean paste with a purple hue.
1) Yoshida et al., Abstracts of the 2022 Annual Meeting of the Agricultural Chemical Society of Japan, 4F04-06
2) Yoshida Kumi, Kawahara Mika: "Method of producing red bean paste", JP2022-41424
