Perparation And Purification Of ACE Inhibitory Peptides From Ruditapes Philippinarum

Ruditapes philippinarum,which is living around our coastal widely, contains a great amount of protein. Studies showed that it has a variety kind of biological activities in its extracts containing antioxidant, hypoglycemic, antibacterial, and so on. There were four aspects of Ruditapes philippinarum was studied in this research, including ACE inhibitory peptides preparation, hydrolysis conditions optimization, active peptides purification, deodorization and function flavoring preparation. The main results were as follows:(1)Hippuric method was used to evaluate the inhibitory activity of angiotensin converting enzyme(ACE) from extracts of Ruditapes philippinarum. Papain was selected for the optimal enzyme from five proteases based on ACE inhibition rate and the degree of hydrolysis. The hydrolysis conditions were optimized by single factor and orthogonal experiments response. The results showed that the optimum conditions of hydrolysis were solid-liquid ratio(m/v)1:30, 1.5% of papain, 90 min of hydrolysis time, at the temperature of 45℃ and p H 6.0.The degree of hydrolysis was 27.75%,the inhibition rate of products on ACE was 18.5%(2mg/m L) and 87.1%(10mg/m L),respectively.(2) Pure products of ACE inhibitory peptide were obtained by a series of purification methods such as ultrafiltration technique, Sephadex G-25, DEAE Sepharose Fast Flow anion exchange chromatography, Sephadex G-15, etc. Purified extracts with the ACE inhibition 51.3%, enzymatic activity of which was significantly increased compared to the crude enzymolysis solution. Kinetic studies showed that inhibition activity was noncompetitive. Results of MALDI-TOF mass spectrometry analysis showed that the molecular weight of clam ACE inhibitory peptides was less 1000 Da. IR spectroscopy analysis showed that benzene was found in the structure of the inhibitory peptides.(3)Seven kinds of macroporous resin and sensory evaluation were used to remove fishiness and as an indicator, respectively from the Ruditapes philippinarum enzyme solution in two means, static and dynamic adsorption. It turned out that AB-8 macroporous resin was the best. Excellent deodorization result was achieved under the following condition:Static adsorption, macroporous resin: enzymatic liquid=1:10, 35 ℃, adsorption deodorization 2h; dynamic adsorption, macroporous resin: enzymatic solution = 1:10, the flow rate of 3m L / min. After the static and dynamic adsorption deodorization, ACE inhibition rate was 46.09%, 52.1% respectively. Activity was found decreased after deodorization treatment.(4) Deodorant sample was used as raw materials for product development, additive like salt, sugar, monosodium glutamate and citric acid to make better flavor evaluated by Sensory evaluation. The optimum formula were optimized by single factor and orthogonal experiments response and the results are: 3g materials, salt 2g, sugar 8g, monosodium glutamate 1.5g, citric 3g, all with the water of 100 m L. ACE inhibition rate of seasoning(peptide concentration of 10 mg / m L) was 47.0%.