Purification and identification of Ace-inhibitory peptides from poultry viscera protein hydrolysate

Three novel Angiotensin I-converting enzyme (ACE) inhibitory peptides were isolated from poultry viscera protein hydrolysate (PVPH). The purification steps involved ultrafiltration of PVPH to eliminate the high molecular weight peptides and RP-HPLC. The ACE inhibitory activity was resolved into three peaks on C18 column with retention times of 15.0, 18.9 and 20.9 min and amino acid sequences of the three peptides were determined to be ARIYH, LRKGNLE and RVWCP, respectively. The peptides exhibited resistance to hydrolysis by gastrointestinal proteases and extreme temperature (100C) and pH (1–12) at least for 2 h. Two of these peptides were competitive inhibitors, while the third was noncompetitive. The in vitro ACE inhibitory activity of PVPH revealed it could be a promising economic source for nutraceutical applications. Practical Applications Poultry viscera is a protein-rich by-product of poultry processing industry. The tissue protein and its hydrolysate offer huge potential for different bioactive peptides. In the present study three novel ACE inhibitory peptides were identified and characterized from poultry viscera protein hydrolysate (PVPH). These peptides could be tested further for their in vivo antihypertensive effect and as functional ingredient in foods.