The influence of fig proteases on the inhibition of angiotensin I-converting and GABA formation in meat

Abstract

The purposes of this research were to use fig protease for texture tenderizing, and to inhibit angiotensin I-converting enzyme (ACE) action and gamma-aminobutyric acid (GABA) formation of meat. Liberated peptides by the enzymatic action of fig protease in processing meat and free amino acids were determined and ACE inhibitory activity was assayed. Meat treated with fig protease became tender as indicated by shear force value (SFV) which was half of those of non-fig treated meat during storage even at 5 degrees C. Liberated peptides, free amino acids and GABA increased while extremely low levels of Glu were detected after storage. The optimal temperature of fig protease against meat was 80 degrees C. However, the activity of fig protease decreased after pre-heating more than 40 degrees C. High ACE inhibitory activity of a mixture of fig and meat was found around 80 degrees C, and the value corresponded to the amount of liberated peptide. A lot of liberated peptides were found at 60-80 degrees C and pasterization of meat product becomes convenient to produce peptides. Production of ACE inhibitory peptides and GABA can be expected as the healthy functional meat product such as antihypertensive activity and improve brain function.