鲜切茭白酚类物质测定及POD特性研究  

Determination of phenol extracted and the characteristics of peroxidase from fresh-cut Zizania latifolia

作　　者：罗海波[1,2] 包永华[3] 何雄[1] 宋慧波[1] 郁志芳[2] 

机构地区：[1]浙江医药高等专科学校生物与食品系,浙江宁波315100 [2]南京农业大学食品科技学院,江苏南京210095 [3]浙江经贸职业技术学院应用工程系,浙江杭州310018

出　　处：《食品工业科技》2012年第15期127-132,共6页Science and Technology of Food Industry

摘　　要：采用紫外光谱扫描及高效液相色谱法对茭白酚提取物进行初步定性分析,同时研究了鲜切茭白的POD特性。结果表明,茭白中的主要酚类物质是咖啡酸和没食子酸,分别占茭白酚提取物总量的25.57%和29.54%,两种酚均可作为鲜切茭白POD的底物,咖啡酸同时也是木质素合成的前体物质,表明茭白不仅具有很强的褐变潜力,而且具备了快速木质化的物质基础。鲜切茭白POD活力很高,其最适pH为6.0,pH5.0～7.0范围内较稳定;最适温度为40.0℃,60℃以上稳定性较差;H2O2浓度在12.25mmol/L以下时,POD活力随H2O2浓度增加直线上升,浓度进一步增加POD活力上升不大,超过14.71mmol/L对POD活力有抑制作用。鲜切茭白POD对焦性没食子酸、咖啡酸、愈创木酚、表儿茶酚、儿茶酚、没食子酸、酪氨酸、肉桂酸及H2O2的Km分别为1.75、5、12、16、41.5、76.2、∞、∞、4.91mmol/L,且与愈创木酚结合时表现出最大酶活力。The phenols of Zizania latifolia were determined by combination of effect of acid and base,scanning spectrum and high performance liquid chromatography（HPLC）,and the characteristics of POD in fresh-cut Z.latifolia were investigated.The results showed that the main phenols of fresh-cut Z.latifolia were gallic acid and caffeic acid,which accounted for 25.57% and 29.54%,respectively,of the total content of Z.latifolia phenol extracts.Both phenols could be used as substrate for the fresh-cut Z.latifolia POD,while caffeic acid also was the precursor substance of lignin synthesis,indicating that fresh-cut Z.latifolia not only had very strong browning potential,but also had the material base of rapid lignification.The POD activity in fresh-cut Z.latifolia was very high.POD had greatest activity at pH6.0 and temperature 40.0℃,and lost activity quickly when pH below 5.0 or temperature above 60℃.The POD activity increased fast when H2O2 was below 12.25 mmol/L,and increased a little afterwards,reached the maximum at the H2O2 level of 14.71 mmol/L,then decreased.The Km for pyrogallic acid,caffeic acid,guaiacol,epicatechin,catechol,gallic acid,tyrosine,cinnamic acid and H2O2 were 1.75,5,12,16,41.5,76.2,∞,∞ and 4.91mmol/L,respectively.The POD showed the highest activity when combined with guaiacol.

关 键 词：鲜切茭白 酚 过氧化物酶 特性 

分 类 号：TS255.1[轻工技术与工程—农产品加工及贮藏工程]