Physico-chemical properties, antioxidant activities and antihypertensive effects of walnut protein and its hydrolysate.
BACKGROUND
Some food proteins hydrolysates are found to possess multiple health effects. In this study, walnut protein (WP) was enzymatically hydrolysed by alcalase and trypsin under optimal conditions. The physico-chemical properties, antioxidant and angiotensin-converting enzyme (ACE) inhibitory activities of WP, alcalase-generated walnut protein hydrolysate (AWPH) and trypsin-generated walnut protein hydrolysate (TWPH) were comparatively studied. Stability properties of the walnut protein hydrolysate (WPH) and the antihypertensive activity in spontaneously hypertensive rats (SHRs) were also investigated.


RESULTS
The WPH showed higher physico-chemical properties, antioxidant activities, ACE inhibitory activity and stability against thermal treatment and gastrointestinal digestion than WP. The results of antihypertensive effects in SHRs showed that the most potent decrease of AWPH and TWPH in the systolic blood pressure occurred at 4 h (-26 mmHg) and 6 h (-30 mmHg) after administration. The study indicated that the WPH could significantly decrease the systolic blood pressure (P < 0.05).


CONCLUSIONS
The WPH exhibited high physico-chemical properties, potent inhibitory activities and high stability. TWPH was more effective than AWPH in the detected properties. The results would be helpful for the comprehensive utilisation of the walnut resources. © 2015 Society of Chemical Industry.
Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, P. R. China.
Xiuming
X
Wang
Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, P. R. China.
Haixia
H
Chen
Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, P. R. China.
Shuqin
S
Li
Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, P. R. China.
Jiangchao
J
Zhou
Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, 300072, P. R. China.
Jiangtao
J
Xu
D000818:Animals; D000959:Antihypertensive Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D006973:Hypertension / Q000188:drug therapy*; D031324:Juglans / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR
D000959:Antihypertensive Agents; D000975:Antioxidants; D010940:Plant Proteins
ACE inhibitory activity; SHRs; antioxidant activities; digestive properties; physico-chemical properties; walnut protein hydrolysate