Matsui T, Matsufuji H, Seki E, Osajima K, Nakashima M, Osajima Y
Department of Food Science and Technology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Biosci Biotechnol Biochem. 1993 Jun;57(6):922-5. doi: 10.1271/bbb.57.922.
Hydrolyzates which inhibit the angiotensin I-converting enzyme (ACE) were prepared from sardine muscle by Bacillus licheniformis alkaline protease. Considering the practical application of preparations as a functional food material, the best proteolytic conditions with respect to taste, solubility and ACE inhibitory activity were a 0.3 wt% addition of the enzyme and 17-h proteolysis at 50 degrees C and pH 9.0. The preparations under these conditions had potent activity (IC50 = 0.26 mg protein/ml). Fractionation of the preparations on an ODS column with ethanol resulted in the production of more potent inhibitors. The most potent activity was obtained when eluting with 10% ethanol (IC50 = 0.015 mg protein/ml). This fraction was apparently rich in acidic amino acids, poor in hydrophobic ones, and effective for use as a physiologically functional food material by virtue of little bitterness, a fish odor and powerful ACE inhibitory activity.
