Characterization of the Norwegian autochthonous cheese Gamalost and its angiotensin I-converting enzyme (ACE) inhibitory activity during ripening

Gamalost, a mould-ripened semi-hard traditional Norwegian cheese, has previously been shown to have a very high angiotensin I-converting enzyme (ACE) inhibition potential compared to other cheeses. In this study the development of the ACE-inhibiting peptides in Gamalost was characterized during ripening. The maximum ACE inhibitory activity of the pH 4.6 soluble fraction of Gamalost was detected after 10 and 20 days of ripening and corresponded to the initial proteolytic activity. During further ripening, a decrease of the ACE inhibitory activity was observed which corresponded to a further increase in the content of free amino acids. From the pH 4.6 soluble fraction of the cheese, 41 different peptides were identified and were found to be derived mainly from beta-casein. The results presented in this paper confirm the ACE-inhibiting activity of Gamalost which peaked between 10 and 20 days of ripening. The ACE-inhibiting activities revealed may indicate that this cheese may have an in vitro antihypertensive effect.