低温碱性脂肪酶型时间-温度指示剂的研究

任兴晨; 茅林春; 苑佳佳; 卢文静

doi:10.13386/j.issn1002-0306.2016.10.042

低温碱性脂肪酶型时间-温度指示剂的研究

Research on low- temperature TTI based on lipase

摘要

摘要: 利用碱性脂肪酶催化三乙酸甘油酯分解导致p H降低,以酸碱指示剂显示颜色变化,研究并确定低温环境的TTI（时间温度指示剂）的反应体系及基本特性。该时间温度指示剂（25 m L）的反应体系为:5 m L三乙酸甘油酯∶20 g/L聚乙烯醇乳化液（v∶v=1∶19,均质10000 r/min,每次3 min,间隔5 min,共两次）、19.50 m L 0.05 mol/L p H10.60Gly-Na OH缓冲液、0.05 m L 1 g/L碱性脂肪酶液、0.25 m L 0.10 mol/L CaCl₂溶液、0.20 m L百里香酚蓝-酚酞-百里酚酞混合指示剂。通过测定反应体系在不同温度下的p H下降速率,最终确定该反应体系的Ea为60.14 k J/mol。该反应体系可应用于监测低温环境下食品中酶反应或脂肪分解的程度,间接判断对应食品的品质状况。

Abstract: The reaction system and basic characteristic of low- temperature TTI( time- temperature indicator) was determined.The TTI was based on the color change of p H indicator resulted from the hydrolysis of triacetin by alkaline lipase.Finally,parameters of 25 m L reaction system was determined: 5 m L triacetin∶ 20 g / L polyvinyl alcohol emulsion( v∶ v = 1∶ 19,10000 r / min,every time 3 min,5 min intervals,a total of 2 times),19.50 m L 0.05 mol / L p H10.60Gly- Na OH buffer,0.05 m L 1 g / L alkaline lipase,0.25 m L 0.10 mol / L CaCl_2 solution,0.20 m L Thymol blue-phenolphthalein- thymolphthalein mixture indicator.The activation energy of TTI was determined to be 60.14 k J / mol by measuring p H descending rate at different temperature.The TTI can be applied to monitor enzyme reaction or steatolysis of low- temperature food,and further to indicate the quality of corresponding food.