[Objectives]This study was conducted to study the total polyphenol content and antioxidant capacity of different extraction fractions of Pholidota chinensis.[Methods]Different polar fractions of P.chinensis were obtai...[Objectives]This study was conducted to study the total polyphenol content and antioxidant capacity of different extraction fractions of Pholidota chinensis.[Methods]Different polar fractions of P.chinensis were obtained by ultrasonic extraction method,and determined for polyphenol contents by UV spectrophotometry,and their antioxidant activity was evaluated by DPPH free radical scavenging and ferric ion reducing antioxidant power(FRAP).SPSS analysis software was used to analyze the correlation between total polyphenol contents and antioxidant activity of different extracts.[Results]The contents of total polyphenols in different polar fractions ranged from 1.52 to 6.41 mg/g,and the order from low to high was:water<petroleum ether<ethyl acetate<95%ethanol.The reduction capacity of the total antioxidant capacity method ranged from 12.54 to 22.45μmol/L,and the order was 95%ethanol>ethyl acetate>petroleum ether>water.The DPPH median inhibition concentration ranged from 0.35 to 2.65 mg/ml,and the order was water>petroleum ether>ethyl acetate>95%ethanol.The total polyphenol content of P.chinensis was best in the 95%ethanol extraction fraction,which showed the strongest total antioxidant capacity,so the total polyphenol content of the 95%ethanol fraction was positively correlated with its antioxidant capacity,while the DPPH free radical-scavenging capacity was better in the water fraction,indicating that the free radical-scavenging capacity of the water fraction was better.[Conclusions]This study provides a theoretical basis for the further study of the chemical components of P.chinensis and the development and utilization of natural antioxidants.展开更多
Changes in total polyphenols, O-diphenols and anthocyanin concentrations during fermentation and drying of pulp pre-conditioned cocoa （Theobroma cacao） beans were investigated using standard analytical methods. Incr...Changes in total polyphenols, O-diphenols and anthocyanin concentrations during fermentation and drying of pulp pre-conditioned cocoa （Theobroma cacao） beans were investigated using standard analytical methods. Increasing pod storage, fermentation and drying led to variable reductions in total polyphenols, O-diphenols and anthocyanins content of the beans. The rates of reduction were however more pronounced during fermentation than pod storage and drying. Storage of cocoa pods between 3-7 days with 6 and 7 days of fermentation and drying respectively retained 85%-90% of the total polyphenol and O-diphenols of the cocoa beans. Similarly, anthocyanin content of beans from the 10 days of pod storage decreased by 70% in the sixth day of fermentation. Pod storage decreased the anthocyanin content at all periods of fermentation. These suggest that the post-harvest treatments of pod storage, fermentation and drying all results in variable reductions in polyphenolic content （total polyphenols and O-diphenols） and anthocyanins content of cocoa beans.展开更多
The microwave-low-pressure process(MWLP)of total polyphenols from Chaenomeles speciosa fruit was studied,and the advantages of MWLP were further evaluated by comparing with ultra high pressure(UHP)and microwave-assist...The microwave-low-pressure process(MWLP)of total polyphenols from Chaenomeles speciosa fruit was studied,and the advantages of MWLP were further evaluated by comparing with ultra high pressure(UHP)and microwave-assisted extraction(MAE).The influences of liquid/solid ratio,extraction time,pressure,and ethanol concentration on the performance of MWLP were investigated.Thereafter,the interactive variables were further optimized by the stepwise multiple quadratic regression model on the basis of the previous univariate analysis.The results showed that temperature as an intermediate variable in MWLP significantly affected the yields of polyphenols and 3-o-caffeoyl-quinic acid,which was determined by pressure and ethanol concentration.The optimized parameters were proved to be valid because the results predicted by the stepwise multiple quadratic regression model equations fit well with the experimental results.Compared with UHP,the predominance of MWLP was that the extraction time was shortened and the cost of extraction equipment was lowered.MWLP is an effective technology since MWLP was superior to MAE based on extraction yield,solvent loss and reproducibility.展开更多
[Objectives] To study the polyphenol oxidase (PPO) activity and total phenol content of Docynia indica .[Methods] The tender branches and petioles of the medicinal and edible plant D. indica were used as experimental ...[Objectives] To study the polyphenol oxidase (PPO) activity and total phenol content of Docynia indica .[Methods] The tender branches and petioles of the medicinal and edible plant D. indica were used as experimental materials, and the annual changes of total phenol content and polyphenol oxidase (PPO) activity were analyzed.[Results] pH 7.0 was the optimum value of polyphenol oxidase activity in D. indica plants;the best substrate was catechol with the concentration of 0.15 mol/L;the optimum temperature was 25 ℃.[Conclusions] The total phenol content of D. indica plants was the lowest in April, May and September of each year. The polyphenol oxidase activity of D. indica plants at flowering and fruiting stage was significantly higher than that at pre-flowering stage.展开更多
This study was carried out to characterize total residual catechins and their fractions, polyphenolic contents and antioxidant activities of black teas enriched with high levels of theaflavin-3,3’-digallate. The made...This study was carried out to characterize total residual catechins and their fractions, polyphenolic contents and antioxidant activities of black teas enriched with high levels of theaflavin-3,3’-digallate. The made teas were processed from eleven selected cultivars. A comparative study was carried out between the processed teas and those from commercially grown Kenyan cultivars in relation to the above chemical parameters. A correlation matrix analysis was also conducted to find out whether a relationship existed between the antioxidant activities and the said chemical parameters. The total residual catechins were found to range between 3.10% and 8.08%. The total polyphenol levels varied between 19.00% and 28.90%, while the antioxidant activities of the teas ranged from 82.70% to 91.70%. There was a significant p < 0.001 correlation between the antioxidant activity and total polyphenols (r = 0.8948). There was also a high correlation p < 0.001 between the antioxidant activity and total catechins (r = 0.8878). Out of the four catechin fractions, the antioxidant activity correlated most with EGCG (r = 0.8774). The total polyphenolic contents and antioxidant activities for most of the cultivars were comparable to those of the green tea reference standard. From the figures obtained, it can be concluded that the most of the newly developed black teas of the selected cultivars have higher quality and enhanced antioxidant activities and that they can be recommended for commercial production.展开更多
Objective:Polyphenols are complex compounds containing multiple phenolic hydroxyl groups.They are widely distributed in plants and have antioxidant activities.Whether the antioxidant activities of the cultivated varie...Objective:Polyphenols are complex compounds containing multiple phenolic hydroxyl groups.They are widely distributed in plants and have antioxidant activities.Whether the antioxidant activities of the cultivated varieties of Echinacea are similar to or better than those of the wild ones and the relationship between the accumulation of polyphenols and their antioxidant activities are still not clear.Methods:Folin-Ciocalteu method,high performance liquid chromatography(HPLC),2,2-diphenyl-1-picrylhydrazyl(DPPH)radical scavenging assay,ferric ion reducing antioxidant power(FRAP)assay,2,2'-azino-bis(3-ethylbenzothiazoline-6)-sulfonic acid(ABTS)radical scavenging assay,and Fe^(2+)chelating ability assay were used,respectively,to detect the total polyphenols and 5 kinds of caffeic acid derivatives(chicoric acid,caffeic acid,caftaric acid,chlorogenic acid,and 1,5-dicaffeoylquinic acid)in the roots,stems,leaves,and flowers,and the antioxidant activities of 3 varieties of Echinacea:E.purpurea L.,cultivar E.purpurea'Aloha',and E.purpurea'White Swan'.Results:E.purpurea L.had the highest contents of total polyphenols,5 caffeic acid derivatives and antioxidant activities,followed by E.purpurea'White Swan'and E.purpurea'Aloha',respectively.E.purpurea'White Swan'had the strongest ability to remove the DPPH,ABTS·^(+)and free radicals,and to chelate Fe^(2+);E.purpurea L.had the strongest ability to reduce FRAP.The correlation analyses revealed that the contents of total polyphenols and caffeic acid derivatives of E.purpurea L.and E.purpurea'White Swan'were correlated with their antioxidant activities.Conclusion:E.purpurea L.was the most appropriate material for the development of medicinal plants.E.purpurea'White Swan'could be used as a substitute for E.purpurea L.in terms of its antioxidant activity.展开更多
基金Supported by Guangxi Science and Technology Base and Talent Project(GK AD21238031)Guangxi Key Laboratory of Zhuang and Yao Ethnic Medicine(GKJZ[2014]32)+8 种基金Collaborative Innovation Center of Zhuang and Yao Ethnic Medicine(GJKY[2013]20)Guangxi Engineering Research Center of Ethnic Medicine Resources and Application(Guifa Gai High Technology Letter[2020]No.2605)The Eighth Batch of Guangxi Specially-employed Expert Projects(GRCTZ[2019]13)Youth Fund Project of Guangxi University of Chinese Medicine(2019QN012)Guangxi Key Research and Development Project(GK AB21196016)National Natural Science Foundation of China(82060695)Guangxi Zhuang Autonomous Region Philosophy and Social Science Planning Research Project(20BMZ005)Foreign Expert Project of the Ministry of Science and Technology of the People s Republic of China(GXL20200233001)Guangxi First-class Discipline of Traditional Chinese Medicine:Ethnic Medicine(GJKY[2018]12).
文摘[Objectives]This study was conducted to study the total polyphenol content and antioxidant capacity of different extraction fractions of Pholidota chinensis.[Methods]Different polar fractions of P.chinensis were obtained by ultrasonic extraction method,and determined for polyphenol contents by UV spectrophotometry,and their antioxidant activity was evaluated by DPPH free radical scavenging and ferric ion reducing antioxidant power(FRAP).SPSS analysis software was used to analyze the correlation between total polyphenol contents and antioxidant activity of different extracts.[Results]The contents of total polyphenols in different polar fractions ranged from 1.52 to 6.41 mg/g,and the order from low to high was:water<petroleum ether<ethyl acetate<95%ethanol.The reduction capacity of the total antioxidant capacity method ranged from 12.54 to 22.45μmol/L,and the order was 95%ethanol>ethyl acetate>petroleum ether>water.The DPPH median inhibition concentration ranged from 0.35 to 2.65 mg/ml,and the order was water>petroleum ether>ethyl acetate>95%ethanol.The total polyphenol content of P.chinensis was best in the 95%ethanol extraction fraction,which showed the strongest total antioxidant capacity,so the total polyphenol content of the 95%ethanol fraction was positively correlated with its antioxidant capacity,while the DPPH free radical-scavenging capacity was better in the water fraction,indicating that the free radical-scavenging capacity of the water fraction was better.[Conclusions]This study provides a theoretical basis for the further study of the chemical components of P.chinensis and the development and utilization of natural antioxidants.
文摘Changes in total polyphenols, O-diphenols and anthocyanin concentrations during fermentation and drying of pulp pre-conditioned cocoa （Theobroma cacao） beans were investigated using standard analytical methods. Increasing pod storage, fermentation and drying led to variable reductions in total polyphenols, O-diphenols and anthocyanins content of the beans. The rates of reduction were however more pronounced during fermentation than pod storage and drying. Storage of cocoa pods between 3-7 days with 6 and 7 days of fermentation and drying respectively retained 85%-90% of the total polyphenol and O-diphenols of the cocoa beans. Similarly, anthocyanin content of beans from the 10 days of pod storage decreased by 70% in the sixth day of fermentation. Pod storage decreased the anthocyanin content at all periods of fermentation. These suggest that the post-harvest treatments of pod storage, fermentation and drying all results in variable reductions in polyphenolic content （total polyphenols and O-diphenols） and anthocyanins content of cocoa beans.
基金This research was supported by China National“12th Five-Year Plan”Scientific and Technological Support Projects(2012BAD31B01 and 2012BAK17B06)from the Ministry of Science and Technology of China.
文摘The microwave-low-pressure process(MWLP)of total polyphenols from Chaenomeles speciosa fruit was studied,and the advantages of MWLP were further evaluated by comparing with ultra high pressure(UHP)and microwave-assisted extraction(MAE).The influences of liquid/solid ratio,extraction time,pressure,and ethanol concentration on the performance of MWLP were investigated.Thereafter,the interactive variables were further optimized by the stepwise multiple quadratic regression model on the basis of the previous univariate analysis.The results showed that temperature as an intermediate variable in MWLP significantly affected the yields of polyphenols and 3-o-caffeoyl-quinic acid,which was determined by pressure and ethanol concentration.The optimized parameters were proved to be valid because the results predicted by the stepwise multiple quadratic regression model equations fit well with the experimental results.Compared with UHP,the predominance of MWLP was that the extraction time was shortened and the cost of extraction equipment was lowered.MWLP is an effective technology since MWLP was superior to MAE based on extraction yield,solvent loss and reproducibility.
基金Supported by Science and Technology Program of Sichuan Province(2018NZ0091)Special Project of Sichuan Provincial Public-Interest Scientific Institution Basal Research FundOpen Fund for Key Laboratory of Coarse Cereal Processing,Ministry of Agriculture and Rural Affairs(2018CC12)
文摘[Objectives] To study the polyphenol oxidase (PPO) activity and total phenol content of Docynia indica .[Methods] The tender branches and petioles of the medicinal and edible plant D. indica were used as experimental materials, and the annual changes of total phenol content and polyphenol oxidase (PPO) activity were analyzed.[Results] pH 7.0 was the optimum value of polyphenol oxidase activity in D. indica plants;the best substrate was catechol with the concentration of 0.15 mol/L;the optimum temperature was 25 ℃.[Conclusions] The total phenol content of D. indica plants was the lowest in April, May and September of each year. The polyphenol oxidase activity of D. indica plants at flowering and fruiting stage was significantly higher than that at pre-flowering stage.
文摘This study was carried out to characterize total residual catechins and their fractions, polyphenolic contents and antioxidant activities of black teas enriched with high levels of theaflavin-3,3’-digallate. The made teas were processed from eleven selected cultivars. A comparative study was carried out between the processed teas and those from commercially grown Kenyan cultivars in relation to the above chemical parameters. A correlation matrix analysis was also conducted to find out whether a relationship existed between the antioxidant activities and the said chemical parameters. The total residual catechins were found to range between 3.10% and 8.08%. The total polyphenol levels varied between 19.00% and 28.90%, while the antioxidant activities of the teas ranged from 82.70% to 91.70%. There was a significant p < 0.001 correlation between the antioxidant activity and total polyphenols (r = 0.8948). There was also a high correlation p < 0.001 between the antioxidant activity and total catechins (r = 0.8878). Out of the four catechin fractions, the antioxidant activity correlated most with EGCG (r = 0.8774). The total polyphenolic contents and antioxidant activities for most of the cultivars were comparable to those of the green tea reference standard. From the figures obtained, it can be concluded that the most of the newly developed black teas of the selected cultivars have higher quality and enhanced antioxidant activities and that they can be recommended for commercial production.
基金supported by the Technology and Development Project of the Finance Department of Guangdong Province,China(No.[2015]639)the Technology Project of the Educational Commission of Guangdong Province of China(No.[2015]3)。
文摘Objective:Polyphenols are complex compounds containing multiple phenolic hydroxyl groups.They are widely distributed in plants and have antioxidant activities.Whether the antioxidant activities of the cultivated varieties of Echinacea are similar to or better than those of the wild ones and the relationship between the accumulation of polyphenols and their antioxidant activities are still not clear.Methods:Folin-Ciocalteu method,high performance liquid chromatography(HPLC),2,2-diphenyl-1-picrylhydrazyl(DPPH)radical scavenging assay,ferric ion reducing antioxidant power(FRAP)assay,2,2'-azino-bis(3-ethylbenzothiazoline-6)-sulfonic acid(ABTS)radical scavenging assay,and Fe^(2+)chelating ability assay were used,respectively,to detect the total polyphenols and 5 kinds of caffeic acid derivatives(chicoric acid,caffeic acid,caftaric acid,chlorogenic acid,and 1,5-dicaffeoylquinic acid)in the roots,stems,leaves,and flowers,and the antioxidant activities of 3 varieties of Echinacea:E.purpurea L.,cultivar E.purpurea'Aloha',and E.purpurea'White Swan'.Results:E.purpurea L.had the highest contents of total polyphenols,5 caffeic acid derivatives and antioxidant activities,followed by E.purpurea'White Swan'and E.purpurea'Aloha',respectively.E.purpurea'White Swan'had the strongest ability to remove the DPPH,ABTS·^(+)and free radicals,and to chelate Fe^(2+);E.purpurea L.had the strongest ability to reduce FRAP.The correlation analyses revealed that the contents of total polyphenols and caffeic acid derivatives of E.purpurea L.and E.purpurea'White Swan'were correlated with their antioxidant activities.Conclusion:E.purpurea L.was the most appropriate material for the development of medicinal plants.E.purpurea'White Swan'could be used as a substitute for E.purpurea L.in terms of its antioxidant activity.
