The present invention provides soy sauce that comprises significant amounts of peptides, and, in particular, hypotensive peptide Gly-Tyr and hypotensive peptide Ser-Tyr, exhibiting a high degree of angiotensin-I-converting enzyme-inhibitory activity and has hypotensive effects while containing no hypotensive agent. Target soy sauce is obtained by mixing soy sauce koji having protease activity of 20 to 300 U/g koji with an aqueous common salt solution and subjecting the mixture to heated digestion, followed by compression filtration. Target soy sauce with a good flavor is obtained by adding soy sauce lactic acid bacteria and soy sauce yeast cells to the moromi mash after heated digestion, and subjecting the resultant to fermentation and maturation, followed by compression filtration.
本发明提供了含有大量肽的酱油,特别是含有降压肽Gly-Tyr和降压肽Ser-Tyr,展现出高度的
血管紧张素转化酶抑制活性,并具有降压作用,同时不含降压剂。目标酱油是通过将具有20至300 U/g酱油麹菌的
蛋白酶活性与
水溶性普通盐溶液混合,并经过加热消化,然后进行压缩过滤而获得的。通过在加热消化后向酱油混糜中添加酱油
乳酸菌和酱油酵母细胞,并经过发酵和成熟,然后进行压缩过滤,可以获得口感好的目标酱油。