title: Precipitation of sword bean proteins by heating and addition of magnesium chloride in a crude extract.
abstract: Sword bean (Canavalia gladiata) seeds are a traditional food in Asian countries. In this study, we aimed to determine the optimal methods for the precipitation of sword bean proteins useful for the food development. The soaking time for sword beans was determined by comparing it with that for soybeans. Sword bean proteins were extracted from dried seeds in distilled water using novel methods. We found that most proteins could be precipitated by heating the extract at more than 90 °C. Interestingly, adding magnesium chloride to the extract at lower temperatures induced specific precipitation of a single protein with a molecular weight of approximately 48 kDa. The molecular weight and N-terminal sequence of the precipitated protein was identical to that of canavalin. These data suggested that canavalin was precipitated by the addition of magnesium chloride to the extract. Our results provide important insights into the production of processed foods from sword bean.
authors.affiliation: a Department of Food Science and Nutrition , School of Human Environmental Sciences, Mukogawa Women's University , Nishinomiya , Japan.
authors.forename: Kaho
authors.initials: K
authors.lastname: Nishizawa
authors.affiliation: b Division of Food Science and Biotechnology , Graduate School of Agriculture, Kyoto University , Uji , Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Masuda
authors.affiliation: c Department of Lifestyle Studies , Kobe Shoin Women's University , Kobe , Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Takenaka
authors.affiliation: a Department of Food Science and Nutrition , School of Human Environmental Sciences, Mukogawa Women's University , Nishinomiya , Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Masui
authors.affiliation: b Division of Food Science and Biotechnology , Graduate School of Agriculture, Kyoto University , Uji , Japan.
authors.forename: Fumito
authors.initials: F
authors.lastname: Tani
authors.affiliation: a Department of Food Science and Nutrition , School of Human Environmental Sciences, Mukogawa Women's University , Nishinomiya , Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Arii
mesh_terms: D032449:Canavalia / Q000737:chemistry*; D011232:Chemical Precipitation / Q000187:drug effects; D005524:Food Technology / Q000379:methods*; D006358:Hot Temperature; D006801:Humans; D007700:Kinetics; D015636:Magnesium Chloride / Q000737:chemistry*; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*; D013025:Glycine max / Q000737:chemistry
chemical_list: D010940:Plant Proteins; D015636:Magnesium Chloride
keywords: canavalin; heating; magnesium chloride; protein precipitation; sword bean