铁棍山药苯丙氨酸解氨酶特性及褐变控制  

Characteristics of Phenylalanine Ammonialyase in Dioscorea opposita Thunb. cv. Tiegun and Its Browning Inhibition

作　　者：赵喜亭[1,2,3] 李艳楠[1] 蒋丽微[1] 马林[1] 王会珍[1] 李明军[1,2,3] 

机构地区：[1]河南师范大学生命科学学院,河南新乡453007 [2]河南省高校道地中药材保育及利用工程技术研究中心,河南新乡453007 [3]绿色药材生物技术河南省工程实验室,河南新乡453007

出　　处：《湖北农业科学》2015年第5期1169-1172,共4页Hubei Agricultural Sciences

基　　金：国家"重大新药创制"科技重大专项子课题(2009ZX09308-002);河南省重点科技攻关项目(112102210300);河南省教育厅自然科学基金项目(2010A180015;2010B360002)

摘　　要：以铁棍山药(Dioscorea opposita Thunb.cv.Tiegun)为试材,采用分光光度法研究了其与褐变相关的山药苯丙氨酸解氨酶(PAL)的特性以及不同抑制剂对PAL活力的影响。结果表明,在试验范围内铁棍山药PAL的最适p H为8.6,不耐碱,更不耐酸;最适温度为50℃,有一定的高温耐受性,即使在80℃条件下保温30 min仍有约12%的活力残存;L-半胱氨酸盐酸盐和柠檬酸对铁棍山药PAL活力具有明显抑制作用,植酸对PAL的抑制作用不明显,而氯化钠能促进PAL活力。为有效抑制PAL引起的鲜切铁棍山药片的褐变,应在酸性(p H<2.0)、低温(<20℃)或高温(>80℃)条件下进行山药切片的加工和贮藏,鲜切片的无硫护色剂应首选L-半胱氨酸盐酸盐,其次是柠檬酸。Dioscorea opposita Thunb. cv. Tiegun was used to study the characteristics of phenylalnine ammonialyase（PAL） related to fresh cut slices browning. The effects of inhibitors on PAL activity were studied. The results showed that in the test range, the optimal pH of PAL in D. opposita Thunb. cv. Tiegun was 8.6. It was not able to endure acid and alkali, especially the former. The optimum temperature was 50 ℃. There was a certain tolerance of high temperature. About 12% of PAL relative activities were still remained even if PAL was incubated at 80 ℃ for 30 min. L-cysteine hydrochloride and citric acid had significant inhibition effect on PAL activity. The inhibition effect of phytic acid on PAL was not obvious. NaC1 promoted PAL activity. In order to inhibit fresh cut slices browning resulting from PAL, processing and storage should be made at the acidic conditions（pH〈2.0）, with the lower temperature （〈20 ℃） or higer temperature（〉80 ℃）. L-cysteine hydrochloride was preferred as anti-browning reagent for fresh cut slices, the second was citric acid.

关 键 词：铁棍山药(Dioscorea opposita Thunb.CV.Tiegun) 苯丙氨酸解氨酶(PAL) 特性 褐变抑制 

分 类 号：R282.4[医药卫生—中药学]