为了推进超高压钝酶技术的工业化进程,以橙汁中的过氧化物酶(POD)为研究对象,通过实验对影响超高压钝酶效果的处理条件(压力、保压时间、pH、温度)进行了考察与评价.在处理温度为室温、保压时间分别为5和20 m in的条件下,200 MPa以下压...为了推进超高压钝酶技术的工业化进程,以橙汁中的过氧化物酶(POD)为研究对象,通过实验对影响超高压钝酶效果的处理条件(压力、保压时间、pH、温度)进行了考察与评价.在处理温度为室温、保压时间分别为5和20 m in的条件下,200 MPa以下压力范围内POD被激活,其活性随压力的增加出现上升趋势,当压力大于200MPa,随着处理压力增加酶活性下降;压力较高时(500 MPa)酶的活性随着保压时间的增加而降低,而在较低的压力(200 MPa),其活性随着保压时间的增加而升高;酶活性随pH的增大先上升后下降;随着温度的上升,酶活性降低.实验结果表明,压力、保压时间、pH值、温度是影响超高压钝酶效果的重要因素.展开更多
The effects of infrared-assisted hot-air drying(IR-HAD),temperature,humidity controlled hot-air drying(THC-HAD),and hot-air drying(HAD)on the drying kinetics,physicochemical properties,chlorogenic acid content and mic...The effects of infrared-assisted hot-air drying(IR-HAD),temperature,humidity controlled hot-air drying(THC-HAD),and hot-air drying(HAD)on the drying kinetics,physicochemical properties,chlorogenic acid content and microstructure of chrysanthemum were experimentally examined.The results showed that the drying time reduced with increasing air drying temperature,with IR-HAD needing the shortest drying time,followed by THC-HAD and HAD.The effective moisture diffusivities(Deff)of chrysanthemum under IR-HAD,THC-HAD,and HAD at 60℃ were 3.22×10^(-9) m^(2)/s,2.19×10^(-9) m^(2)/s,and 2.89×10^(-9) m^(2)/s,respectively.IR-HAD preserved chrysanthemum surface color better than THC-HAD and HAD,whereas the THC-HAD samples obtained higher water holding capacity(WHC),water binding capacity(WBC),and chlorogenic acid content.Additionally,peroxidase(POD)residual activity of the samples decreased with increasing blanching time.The current work provides a theoretical basis for the drying of chrysanthemum.展开更多
[Objective] To study the effects of microwave blanching treatment on POD activity and crispness in Capsicum frutescens L., and to compare the effects of microwave blanching method, normal blanching method, boiling wat...[Objective] To study the effects of microwave blanching treatment on POD activity and crispness in Capsicum frutescens L., and to compare the effects of microwave blanching method, normal blanching method, boiling water blanching and steam blanching. [Methods] In order to obtain the optimal condition for microwave blanching, response surface methodology was used to construct a quadratic regression model describing the effects of microwave power, microwave time and calcium lactate concentration on the POD activity in C. frutescens. [Results] The optimal technology was obtained based on central composite design： 525 W microwave power, 64.5 s microwave time, and 0.08% calcium lactate concentration. Under this condition, POD enzyme activity of C. frutescens was desactivated and crispness of C. frutescens was 68.77 N. [Conclusions] This research would provide references for the crispness protection and enzyme deactivation of C. frutescens.展开更多
Chemodynamic therapy (CDT) has attracted tremendous interest in cancer therapy because it is independent of oxygen and photoirradiation. However, the therapeutic efficacy of CDT is restricted by insufficient H_(2)O_(2...Chemodynamic therapy (CDT) has attracted tremendous interest in cancer therapy because it is independent of oxygen and photoirradiation. However, the therapeutic efficacy of CDT is restricted by insufficient H_(2)O_(2) levels in tumor cells. Herein, employing endogenous GSH as a template and cationic polymeric chitosan (CS) as crosslinker and stabilizer exhibiting easy cell uptake, red luminescent gold nanoclusters (denoted CS-GSH@AuNCs) were successfully synthesized in HeLa cells. The in situ synthesized CS-GSH@AuNCs exhibited both superoxidase dismutase (SOD) and peroxidase (POD)-like activity, which could promote the production of H_(2)O_(2) from superoxide anion radicals (O_(2)^(·-)) and then ^(·)OH. The combination of GSH elimination and H_(2)O_(2) elevation boosted the generation of ^(·)OH, which could trigger cancer cell apoptosis and death. The enzyme-like activity of CS-GSH@AuNCs could be effectively activated under acidic conditions, and showed a high killing effect on tumor cells but minimal toxicity to normal cells. The developed GSH consumption and ^(·)OH promotion theranostic platform is an innovative route for enhanced CDT by the amplification of oxidative stress.展开更多
基金This work was supported by China Agriculture Research System(CARS-21).
文摘The effects of infrared-assisted hot-air drying(IR-HAD),temperature,humidity controlled hot-air drying(THC-HAD),and hot-air drying(HAD)on the drying kinetics,physicochemical properties,chlorogenic acid content and microstructure of chrysanthemum were experimentally examined.The results showed that the drying time reduced with increasing air drying temperature,with IR-HAD needing the shortest drying time,followed by THC-HAD and HAD.The effective moisture diffusivities(Deff)of chrysanthemum under IR-HAD,THC-HAD,and HAD at 60℃ were 3.22×10^(-9) m^(2)/s,2.19×10^(-9) m^(2)/s,and 2.89×10^(-9) m^(2)/s,respectively.IR-HAD preserved chrysanthemum surface color better than THC-HAD and HAD,whereas the THC-HAD samples obtained higher water holding capacity(WHC),water binding capacity(WBC),and chlorogenic acid content.Additionally,peroxidase(POD)residual activity of the samples decreased with increasing blanching time.The current work provides a theoretical basis for the drying of chrysanthemum.
基金Supported by the Key Project of Chongqing City(cstc2014yykfA0030)~~
文摘[Objective] To study the effects of microwave blanching treatment on POD activity and crispness in Capsicum frutescens L., and to compare the effects of microwave blanching method, normal blanching method, boiling water blanching and steam blanching. [Methods] In order to obtain the optimal condition for microwave blanching, response surface methodology was used to construct a quadratic regression model describing the effects of microwave power, microwave time and calcium lactate concentration on the POD activity in C. frutescens. [Results] The optimal technology was obtained based on central composite design： 525 W microwave power, 64.5 s microwave time, and 0.08% calcium lactate concentration. Under this condition, POD enzyme activity of C. frutescens was desactivated and crispness of C. frutescens was 68.77 N. [Conclusions] This research would provide references for the crispness protection and enzyme deactivation of C. frutescens.
基金supported by the National Natural Science Foundation of China (No. 22074007)。
文摘Chemodynamic therapy (CDT) has attracted tremendous interest in cancer therapy because it is independent of oxygen and photoirradiation. However, the therapeutic efficacy of CDT is restricted by insufficient H_(2)O_(2) levels in tumor cells. Herein, employing endogenous GSH as a template and cationic polymeric chitosan (CS) as crosslinker and stabilizer exhibiting easy cell uptake, red luminescent gold nanoclusters (denoted CS-GSH@AuNCs) were successfully synthesized in HeLa cells. The in situ synthesized CS-GSH@AuNCs exhibited both superoxidase dismutase (SOD) and peroxidase (POD)-like activity, which could promote the production of H_(2)O_(2) from superoxide anion radicals (O_(2)^(·-)) and then ^(·)OH. The combination of GSH elimination and H_(2)O_(2) elevation boosted the generation of ^(·)OH, which could trigger cancer cell apoptosis and death. The enzyme-like activity of CS-GSH@AuNCs could be effectively activated under acidic conditions, and showed a high killing effect on tumor cells but minimal toxicity to normal cells. The developed GSH consumption and ^(·)OH promotion theranostic platform is an innovative route for enhanced CDT by the amplification of oxidative stress.
