The protein profile of perch essence and its improvement of metabolic syndrome in vitro

The objective of this study was to analyze the protein profile and amino acid composition of perch essence processed by high-pressure extraction compared with mackerel, and milkfish. The inhibitory activities of three essences were determined against digestive enzymes relevant to the metabolic syndrome such as the angiotensin-converting enzyme (ACE), pancreatic lipase, α-amylase, and α-glucosidase. The results showed that perch essence exhibits the highest recovery by using the same extraction method for all three fish species. The amounts of all hydrolyzed amino acids, except histidine, were approximately double in perch compared with the other two fish. The perch essence contained the most abundant soluble protein and amino acids composition related to metabolic syndrome. In vitro anti-hypertensive, hypoglycemic, and anti-obesity potency of perch essence exhibited the highest among the three fishes. Although the amounts of free amino acids were similar in the three fish species, the molecular weight distribution from gel filtration chromatographic analysis indicated that perch essence contained 32.4% of peptides with a molecular weight of less than 2.3 kDa. This study suggested that naturally occurring bioactive peptides in perch essence might potentially serve as a good source of functional food supplements for metabolic syndrome.