Evaluation of mechanically deboned poultry meat hydrolysates on the antioxidative and antihypertensive properties

• Main Authors: Meng-Jian Li, 李孟展
• Other Authors: 譚發瑞
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/07774234684137572333

碩士 === 國立中興大學 === 動物科學系所 === 100 === In recent years, chicken cut is the major poultry consumption type in Taiwan. Along with the increase of poultry consumption, some wastes which might cause environment pollution become great concern for the industry. Not only reuses the meat remaining on the skeleton, utilization of mechanically deboned poultry meat (MDPM) also increases its extra value for further processing, and reduce the potent environmental pollution. Therefore, the objective of this study was to hydrolyze MDPM with various enzymes, including Monascus purpureus extract, Alcalase, pepsin or papain, and to evaluate the antioxidative and antihypertensive properties in vitro and in vivo of these MDPM protein hydrolysates. The results showed that the MDPM hydrolyzed with papain had higher degree of hydrolysis and solubility. The pepsin hydrolysates had the highest L* values, whereas the Monascus purpureus extract hydrolysates had the highest a* values. Analysis of amino acid composition showed that MDPM hydrolysate solutions contained higher amounts of glutamic acid, aspartic acid and leucine. Moreover, MDPM hydrolysate solutions also had higher amounts of alanine, glycine, valine and lysine. Monascus purpureus extract hydrolysates showed higher total amino acid content and total hydrophobic amino acid content than other treatments. Even though the pepsin hydrolysates had lower total amino acid content and total hydrophobic amino acid content, it had the highest total hydrophobic amino acids/total amino acids ratio. The Monascus purpureus extract hydrolysates had proteolytic activity of 346.88 μg/ml at pH 5. The Alcalase and papain hydrolysates had higher DPPH radical scavenging ability and ferrous ion chelating ability, whereas the Monascus purpureus extract hydrolysates had the highest reducing power. The analysis of molecular weight distribution of hydrolysate showed that a less efficiency of hydrolysis of Monascus purpureus extract hydrolysates, and its molecular weight distribution ranged from 500 to 12,000 m/z. While a better hydrolysis efficiency was observed in the papain hydrolysate due to its narrower molecular weight distribution (lower than 6000 m/z). ACE inhibitory results showed that pepsin hydrolysates had the highest ACE inhibitory, followed by Alcalase and papain, and finally Monascus purpureus extracts. Four treatments, including orally administration to spontaneously hypertensive rats (SHR) with distilled water (control), 300 mg/kg concentration of Monascus purpureus extracts or pepsin, and 50 mg/kg concentration of captopril (positive control), were conducted in the in vivo blood pressure test. The results showed that the immediate systolic and diastolic blood pressures of tested animals decreased then increased after 6-8 h. The blood pressures of Monascus purpureus extracts, pepsin, and captopril treatments were lower than those of the control. In the long-term test, systolic and diastolic blood pressures increased with ages, but the blood pressures of Monascus purpureus extracts and pepsin treatments were lower than those of the control, especially after 5-6 weeks. No significant difference was observed in body weight, heart weight, and heart weight/live weight ratio between the pepsin and Monascus purpureus extract treatments. Also, the thickness of coronary artery wall of hydrolysate treatments was significantly lower than the control. In conclusion, mechanically deboned poultry meat hydrolysates exhibited good antioxidative and antihypertensive properties which make it as a potent candidate component in functional foods. Further work which conducted to purify and confirm the functionality of peptide sequences is needed.