Production, in continuous enzymatic membrane reactor, of an anti-hypertensive hydrolysate from an industrial alfalfa white protein concentrate exhibiting ACE inhibitory and opioid activities

A few hydrolysates of food proteins were reported to exert an antihypertensive effect in vivo due to angiotensin I converting enzyme (ACE) inhibitory peptides or opioid peptides. An industrial alfalfa white protein concentrate (AWPC) hydrolysate, produced on a pilot plant scale, strongly inhibited ACE with an IC50 value of 8.8 μg/ml. Furthermore, the AWPC hydrolysate inhibited the spontaneous contraction of rabbit ileum in a dose-dependent and naloxone-blocked manner, indicating the presence of opioid peptides. The AWPC hydrolysate significantly lowered blood pressure of spontaneously hypertensive rats (SHR) more than 6 h after a single oral administration. The maximum reduction of systolic blood pressure (−29.9 ± 2.0 mmHg) was observed 4 h after an oral administration of 0.5 g/kg hydrolysate dosage. The minimal anti-hypertensive effect was observed for 0.1 g/kg dosage. The AWPC hydrolysate may then be particularly suitable as nutraceutical for functional food useful in the prevention of hypertension.