PROBLEM TO BE SOLVED: To provide a method for producing useful five kinds of dipeptides and a peptide composition comprising the dipeptides, each having angiotensin converting enzyme-inhibitory activity, thereby exhibiting hypotensive effect.SOLUTION: The method for producing a composition as permeated fraction, or dipeptides having amino acid sequences of Trp-Leu, Leu-Trp, Trp-Ile, Val-Tyr and Trp-Asn, respectively, is provided, comprising the following steps: protein of fish meat origin is reacted at 40-60°C under an optimum condition of pH 5.0-9.0 in the presence of a protease for use in the food industry to conduct an enzymatic hydrolysis of the water-insoluble protein, and from the resultant hydrous hydrolytic reaction mixture, an adsorbed fraction is obtained by a hydrophobic resin column method, which is then subjected to ultrafiltration (molecular weight 1,000).COPYRIGHT: (C)2013,JPO&INPIT【課題】アンジオテンシン変換酵素を阻害する活性をもち、このことにより、血圧降下作用を示す有用な5種類のジペプチドおよびそれを含有するペプチド組成物の製造方法を提供する。【解決手段】魚肉性タンパク質を、食品工業用プロテアーゼをpH5.0~9.0の至適条件下に40~60℃の温度で反応させ、これにより該水不溶性タンパク質の酵素的加水分解を行い、得られた含水の加水分解反応混合物から疎水性樹脂カラム法により得られた吸着画分をさらに限外ろ過(分子量1000)に負荷することから成る、透過画分の組成物、又はTrp-Leu、Leu-Trp、Trp-Ile、Val-Tyr又はTrp-Asnのアミノ酸配列を有するジペプチドの製造方法。【選択図】なし
