Zhu Ming-Ming, Wang Shu-Lin, Fan Ming-Tao, Li Jing
1College of Food Science and Engineering, Northwest A&F University, Yangling, China.
2Agriculture and Animal Husbandry College, Qinghai University, Qinghai, China.
Food Sci Biotechnol. 2016 Feb 29;25(1):221-227. doi: 10.1007/s10068-016-0033-7. eCollection 2016.
Reactions of a crude enzyme extracted from TS-82 to cleave carbon-carbon bonds in bicyclic and monocyclic carotenoid substrates were investigated. Dependencies of enzyme activities on processing temperature and pH were investigated and non-volatile and volatile breakdown products were characterized. The crude enzyme showed a maximum activity with zeaxanthin, followed in decreasing order by β-carotene, canthaxanthin, astaxanthin, and β-apo-8'-carotenal. The optimum pH value of the enzyme was 3.0 for both bicyclic and monocyclic substrates, whereas the optimum temperature of the enzyme was substrate specific at 60°C for C carotenoids and 50°C for β-apo-8'-carotenal. Liquid Chromatography-Mass Spectra (LC-MS) and Gas Chromatography- Mass Spectra (GC-MS) indicated that the crude enzyme was able to catalyze substrates with cleavage at 9-10 and 9'-10' double bonds with C norisoprenoids being the main volatile reaction products in each case. Astaxanthin is a major source for α,β-dihydro-β-ionone.
对从TS-82中提取的粗酶催化双环和单环类胡萝卜素底物中碳-碳键断裂的反应进行了研究。研究了酶活性对加工温度和pH值的依赖性，并对非挥发性和挥发性分解产物进行了表征。粗酶对玉米黄质的活性最高，其次是β-胡萝卜素、角黄素、虾青素和β-阿朴-8'-胡萝卜醛，活性依次降低。对于双环和单环底物，该酶的最佳pH值均为3.0，而该酶的最佳温度因底物而异，对于C类胡萝卜素为60°C，对于β-阿朴-8'-胡萝卜醛为50°C。液相色谱-质谱联用仪（LC-MS）和气相色谱-质谱联用仪（GC-MS）表明，粗酶能够催化底物在9-10和9'-10'双键处断裂，每种情况下C-降异戊二烯类化合物都是主要的挥发性反应产物。虾青素是α,β-二氢-β-紫罗兰酮的主要来源。
