In order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense (R. Br.) Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction ...In order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense (R. Br.) Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction time on polyphenols extraction rate were investigated. On the basis of single-factor test, a four-factor and three-level orthogonal test was designed by response surface method to establish a mathematical model between the response value and various factors. The results showed that the intensity of effect of different influencing factor on polyphenols ex- traction rate ranked as microwave power's〉solid to liquid ratio's〉extraction time's〉 ethanol concentration's. The optimum microwave-assisted extraction conditions for polyphenols from L. chinense were as follows: extraction power 254 W, ethanol concentration 60%, extraction time 12.5 rain and solid to liquid ratio 1:17. Under the optimum extraction conditions, the extraction rate of polyphenols from L. chinense was 19.17%.展开更多
In order to understand the physiological and biochemical reasons of leafcolor transformation in Loropetalum chinense var. rubrum,three types of L. chinense var. rubrum, Zihei (black purple), Zihong(red purple)and Hong...In order to understand the physiological and biochemical reasons of leafcolor transformation in Loropetalum chinense var. rubrum,three types of L. chinense var. rubrum, Zihei (black purple), Zihong(red purple)and Hongzhe(red_ochre), and L. chinense were taken as materials. The contents of chlorophyll, carotenoid and soluble sugar, and activity of phenylalanine ammonialyase (PLA) in the leaves were measured from early March to June. The results showed that the contents of chlorophyll, carotenoid and soluble sugar increased gradually during the leafcolor changing from red to green, but there were obviously differences among types of Zihei, Zihong and Hongzhe. Anthocyanins contents in Zihe and Zihong leaves maintained high level, so their leaves still kept red when they got mature in early June. Phenylalanine ammonialyase (PLA) activity decreased, and had positive relationship with anthocyanin contents. Some measures such as shading or watering to lower air temperature could be taken to maintain leaves of L. chinense var. rubrum fresh red during summer.展开更多
基金Supported by Open Funds for Innovation Platforms of Colleges and Universities in Hunan Province(15K066)National College Students'Innovative Entrepreneuria Training Program(201510553003)Research Study and Innovative Experiment Plan Project for College Students in Hunan Province(2015-499)~~
文摘In order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense (R. Br.) Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction time on polyphenols extraction rate were investigated. On the basis of single-factor test, a four-factor and three-level orthogonal test was designed by response surface method to establish a mathematical model between the response value and various factors. The results showed that the intensity of effect of different influencing factor on polyphenols ex- traction rate ranked as microwave power's〉solid to liquid ratio's〉extraction time's〉 ethanol concentration's. The optimum microwave-assisted extraction conditions for polyphenols from L. chinense were as follows: extraction power 254 W, ethanol concentration 60%, extraction time 12.5 rain and solid to liquid ratio 1:17. Under the optimum extraction conditions, the extraction rate of polyphenols from L. chinense was 19.17%.
文摘In order to understand the physiological and biochemical reasons of leafcolor transformation in Loropetalum chinense var. rubrum,three types of L. chinense var. rubrum, Zihei (black purple), Zihong(red purple)and Hongzhe(red_ochre), and L. chinense were taken as materials. The contents of chlorophyll, carotenoid and soluble sugar, and activity of phenylalanine ammonialyase (PLA) in the leaves were measured from early March to June. The results showed that the contents of chlorophyll, carotenoid and soluble sugar increased gradually during the leafcolor changing from red to green, but there were obviously differences among types of Zihei, Zihong and Hongzhe. Anthocyanins contents in Zihe and Zihong leaves maintained high level, so their leaves still kept red when they got mature in early June. Phenylalanine ammonialyase (PLA) activity decreased, and had positive relationship with anthocyanin contents. Some measures such as shading or watering to lower air temperature could be taken to maintain leaves of L. chinense var. rubrum fresh red during summer.