ABSTRACT
Objective: Traditional fermented meat products can be considered a source of bioactive peptides. Cangkuk, a traditional Indonesian fermented beef product is one source of ACE inhibitory peptides. This study aimed to identify ACE-inhibitory peptides from Cangkuk and analyze their antihypertensive effects. Methods: The water-soluble fraction of Cangkuk was fractionated to obtain ACE-inhibitory peptides using an ethanol solvent at several concentrations and solid-phase extraction with an OASIS HLB cartridge followed by purification with RP-HPLC. HPLC-MS was used to identify target peptides, followed by automatic protein sequencer analysis to detect peptide sequences. Antihypertensive effects were analyzed on the water-soluble fraction and synthesized peptides. The animal model was comprised of 14-16-week-old male spontaneously hypertensive rats (SHRs) [~320 g average body weight] with mean systolic blood pressures (SBPs) higher than 190 mm Hg. All oral doses of peptides were 1 mL in volume. Distilled water was used as a control. The antihypertensive activities of the sample and control were observed by measuring the SBP at 0, 2, 4, 6, 8 and 24 h after oral administration. Results: Two sequences of ACE inhibitory peptides were found, EAPLNPKANR (IC50 value of 44.6 µmol L-1) and IVG (IC50 value of 97.3 µmol L-1). The water-soluble fraction demonstrated an antihypertensive effect on SHRs after oral administration at 100 mg kg-1 body weight, maximally lowering the SBP by 14.9 mm Hg 8 h after administration. The tripeptide IVG showed the highest reduction of SBP, 24.76±2.1 mm Hg 8 h after administration. The decapeptide EAPLNPKANR showed the highest reduction of SBP, 21.0 ±1.9 mm Hg, 8 h after administration. All the samples differed significantly from the control (p<0.01). Conclusion: Cangkuk has potential as a functional food ingredient acting as an antihypertensive agent.
ABSTRACT
BACKGROUND: The meat of Kacang goat has potential for production of a protein hydrolysate. Functional ingredients from protein hydrolysate of Kacang goat meat were determined by the consistency of angiotensin-converting enzyme (ACE) inhibitory activity and antihypertensive effect. This study examined the potency of Kacang goat protein hydrolysate in ACE inhibition and antihypertensive activity. RESULT: Protein hydrolysates of Kacang goat meat were prepared using sequential digestion of endo-proteinase and protease complex at several concentrations and hydrolysis times. The highest ACE inhibitory activity resulted from a hydrolysate that was digested for 4 h with 5 g kg(-1) of both enzymes. An ACE inhibitory peptide was purified and a novel peptide found with a sequence of Phe-Gln-Pro-Ser (IC50 value of 27.0 µmol L(-1) ). Both protein hydrolysates and a synthesised peptide (Phe-Gln-Pro-Ser) demonstrated potent antihypertensive activities in spontaneously hypertensive rats. CONCLUSION: Protein hydrolysate of Kacang goat meat produced by sequential digestion with endo-proteinase and protease complex has great potential as a functional ingredient, particularly as an antihypertensive agent. © 2015 Society of Chemical Industry.
