Characterization of Millet Proteins and Making Lactic Acid Beverage

アワやキビなどの雑穀類は近年再評価されている｡本報告ではHDL (善玉コレステロール)上昇効果を有する雑穀タンパク質の解析と利用方法を検討した｡Landry-Moureaux の溶媒抽出法により得られた蛋白質5画分のうち､プロラミン画分は全タンパク質の60-80%を占めていた.SDS-PAGEによりアワ及びキビプロラミンを分画したところ､GIx､ALa､Leuがそれぞれ15%以上を占めるポリペプチドとMet､Pro含量の高いポリペプチドで構成されており､トウモロコシゼインと相似性を有することがわかった｡また､雑穀タンパク質の有効な利用方法として乳酸 菌で醗酵を誠みたところ､供試菌株中では､Streptococcus thermophilus(IFO 13957)をスター ターとした場合にpHが4以下まで低下し､風味も優れていた。We have previously reported that millet dietary protein elevated the plasma levels of HDL cholesterol in rats. In this study, We examined the composition of the polypeptides of millets protein to determine if the structure of millets protein may lead to an explanation of the efects of these grains. The proteins extracted from foxtail and proso millets were 64.1% and 80.0% prolamin, respectively. The polypeptides of the prolamins were classirled into two groups. The major polypeptides of 27-19 kDa were rich in leucine and alanine, whereas the 17-14 kDa polypeptides were rich in methionine and proline. These results showed that the major polypeptides of prolamin were homologous to zein. We also investigated making a lactic acid beverage by using millets protein in fermentation. Three lactic acid bacteria were used, Streptococcus thermophilus(IFO13957) was a suitable strain under our condition