Hplc-dad-esi/ms Identification And Quantification Of Phenolic Compounds In Ilex Paraguariensis Beverages And On-line Evaluation Of Individual Antioxidant Activity.

Chimarrão and tererê are maté (dried, toasted and milled Ilex paraguariensis leaves and stemlets) beverages widely consumed in South America. This paper describes the application of HPLC-DAD-ESI/MS method for the identification and quantification of caffeoylquinic acids (CQA), flavonol glycosides and purine alkaloids in these beverages. The beverage samples were prepared from commercial lots of maté from Southern Brazil. The caffeoylquinic acids, 4,5-diCQA, 3-CQA, 5-CQA, and 4-CQA were the major compounds, having 238-289, 153-242, 183-263, and 123-188 μg/mL, respectively, for chimarrão and 206-265, 122-218, 164-209, 103-169 μg/mL, respectively, for tererê. Caffeine also had high amounts while glycosides of quercetin and kaempferol were found at much lower levels. The individual antioxidant activity was also determined by an on-line system that measured their ABTS•+ radical scavenging activity, showing that the antioxidant capacity was not proportional to the concentrations of the phenolic compounds. 3-CQA, quercetina-3-O-ramnosylglucoside, and quercetina-3-O-glucoside were the major contributors to the antioxidant capacity, although the quercetin glycosides had concentrations less than 10 times that of 3-CQA.183859-7

The Antioxidant Capacity of Rosemary and Green Tea Extracts to Replace the Carcinogenic Antioxidant (BHA) in Chicken Burgers

The present study aimed to evaluate the effect of natural extracts (rosemary and green tea extracts) in frozen storage of chicken burgers. Chicken burger treatments were prepared as follows: control (CON), 20 mg BHA/kg (BHA20), 10 mg green tea extract/kg (GT10), 38 mg green tea extract/kg (GT38), 18.6 mg rosemary extract/kg (RO18), and 480 mg rosemary extract/kg (RO480). Analysis of physicochemical parameters, color, TBAR index, and sensory acceptance were performed at 0, 30, 60, and 120 days of storage at −18°C in burgers packaged in LDPE plastic bags. The addition of natural antioxidants did not affect (p>0.05) the color and physicochemical parameters of the chicken burgers. After 120 days at −18°C, the RO480 sample showed a TBAR index similar (p>0.05) to BHA20 (0.423 and 0.369 mg, resp.). Sensory acceptance did not differ (p>0.05) among the treatments throughout the storage period (p>0.05)

Optimization of a method for determination of phenolic acids in exotic fruits by capillary electrophoresis

In this work, the separation of nine phenolic acids (benzoic, caffeic, chlorogenic, p-coumaric, ferulic, gallic, protocatechuic, syringic, and vanillic acid) was approached by a 32 factorial design in electrolytes consisting of sodium tetraborate buffer(STB) in the concentration range of 10-50 mmol L(-1) and methanol in the volume percentage of 5-20%. Derringer`s desirability functions combined globally were tested as response functions. An optimal electrolyte composed by 50 mmol L(-1) tetraborate buffer at pH 9.2, and 7.5% (v/v) methanol allowed baseline resolution of all phenolic acids under investigation in less than 15 min. In order to promote sample clean up, to preconcentrate the phenolic fraction and to release esterified phenolic acids from the fruit matrix, elaborate liquid-liquid extraction procedures followed by alkaline hydrolysis were performed. The proposed methodology was fully validated (linearity from 10.0 to 100 mu g mL(-1), R(2) > 0.999: LOD and LOQ from 1.32 to 3.80 mu g mL(-1) and from 4.01 to 11.5 mu g mL(-1), respectively; intra-day precision better than 2.8% CV for migration time and 5.4% CV for peak area; inter-day precision better than 4.8% CV for migration time and 4.8-11% CV for peak area: recoveries from 81% to 115%) and applied successfully to the evaluation of phenolic contents of abiu-roxo (Chrysophyllum caimito), wild mulberry growing in Brazil (Morus nigra L.) and tree tomato (Cyphomandra betacea). Values in the range of 1.50-47.3 mu g g(-1) were found, with smaller amounts occurring as free phenolic acids. (C) 2009 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundaqao de Amparo a Pesquisa do Estado de Sao Paulo of Brazil (Fapesp)[04/08503-2]Fundaqao de Amparo a Pesquisa do Estado de Sao Paulo of Brazil (Fapesp)[04/08931-4]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundaqao de Amparo a Pesquisa do Estado de Sao Paulo of Brazil (Fapesp)[07/53470-3]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Cientifico a Tecnologico of Brazil (CNPq)[300595/2007-7

HPLC-DAD-ESI/MS Identification and Quantification of Phenolic Compounds in Ilex paraguariensis Beverages and On-Line Evaluation of Individual Antioxidant Activity

“Chimarrão” and “tererê” are maté (dried, toasted and milled Ilex paraguariensis leaves and stemlets) beverages widely consumed in South America. This paper describes the application of HPLC-DAD-ESI/MS method for the identification and quantification of caffeoylquinic acids (CQA), flavonol glycosides and purine alkaloids in these beverages. The beverage samples were prepared from commercial lots of maté from Southern Brazil. The caffeoylquinic acids, 4,5-diCQA, 3-CQA, 5-CQA, and 4-CQA were the major compounds, having 238–289, 153–242, 183–263, and 123–188 μg/mL, respectively, for chimarrão and 206–265, 122–218, 164–209, 103–169 μg/mL, respectively, for tererê. Caffeine also had high amounts while glycosides of quercetin and kaempferol were found at much lower levels. The individual antioxidant activity was also determined by an on-line system that measured their ABTS•+ radical scavenging activity, showing that the antioxidant capacity was not proportional to the concentrations of the phenolic compounds. 3-CQA, quercetina-3-O-ramnosylglucoside, and quercetina-3-O-glucoside were the major contributors to the antioxidant capacity, although the quercetin glycosides had concentrations less than 10 times that of 3-CQA

Determination of catechins in green tea infusions by reduced flow micellarelectrokinetic chromatography

A sulfated-β-cyclodextrin (s-β-CD) modified reduced flow micellar electrokinetic chromatography (RF-MEKC) method was developed and validated for the determination of catechins in green tea. The optimal electrolyte consisted of 0.2% triethylamine, 50 mmol/L SDS and 0.8% s-β-CD (pH = 2.9), allowing baseline separation of five catechins in 4 min. The samples and standards were injected at 0.6 psi for 5 s under constant voltage of −30 kV. Sample preparation simply involved extraction of 2 g of tea with 200 mL water at 95 °C under constant stirring for 5 min. The method demonstrated excellent performance, with limits of detection (LOD) and quantification (LOQ) of 0.02–0.1 and 0.1–0.5 μg/mL, respectively, and recovery percentages of 94–101%. The method was applied to six samples of Brazilian green tea infusions. Epigallocatechin gallate (23.4–112.4 μg/mL) was the major component, followed by epigallocatechin (18.4–78.9 μg/mL), epicatechin gallate (5.6–29.6 μg/mL), epicatechin (4.6–14.5 μg/mL) and catechin (3.2–8.2 μg/mL)127265165

HPLC-DAD-ESI/MS Identification and Quantification of Phenolic Compounds in Ilex paraguariensis Beverages and On-Line Evaluation of Individual Antioxidant Activity

“Chimarrão” and “tererê” are maté (dried, toasted and milled Ilex paraguariensis leaves and stemlets) beverages widely consumed in South America. This paper describes the application of HPLC-DAD-ESI/MS method for the identification and quantification of caffeoylquinic acids (CQA), flavonol glycosides and purine alkaloids in these beverages. The beverage samples were prepared from commercial lots of maté from Southern Brazil. The caffeoylquinic acids, 4,5-diCQA, 3-CQA, 5-CQA, and 4-CQA were the major compounds, having 238–289, 153–242, 183–263, and 123–188 μg/mL, respectively, for chimarrão and 206–265, 122–218, 164–209, 103–169 μg/mL, respectively, for tererê. Caffeine also had high amounts while glycosides of quercetin and kaempferol were found at much lower levels. The individual antioxidant activity was also determined by an on-line system that measured their ABTS•+ radical scavenging activity, showing that the antioxidant capacity was not proportional to the concentrations of the phenolic compounds. 3-CQA, quercetina-3-O-ramnosylglucoside, and quercetina-3-O-glucoside were the major contributors to the antioxidant capacity, although the quercetin glycosides had concentrations less than 10 times that of 3-CQA

Determination Of Catechins In Green Tea Infusions By Reduced Flow Micellar Electrokinetic Chromatography.

A sulfated-β-cyclodextrin (s-β-CD) modified reduced flow micellar electrokinetic chromatography (RF-MEKC) method was developed and validated for the determination of catechins in green tea. The optimal electrolyte consisted of 0.2% triethylamine, 50mmol/L SDS and 0.8% s-β-CD (pH=2.9), allowing baseline separation of five catechins in 4min. The samples and standards were injected at 0.6psi for 5s under constant voltage of -30kV. Sample preparation simply involved extraction of 2g of tea with 200mL water at 95°C under constant stirring for 5min. The method demonstrated excellent performance, with limits of detection (LOD) and quantification (LOQ) of 0.02-0.1 and 0.1-0.5μg/mL, respectively, and recovery percentages of 94-101%. The method was applied to six samples of Brazilian green tea infusions. Epigallocatechin gallate (23.4-112.4μg/mL) was the major component, followed by epigallocatechin (18.4-78.9μg/mL), epicatechin gallate (5.6-29.6μg/mL), epicatechin (4.6-14.5μg/mL) and catechin (3.2-8.2μg/mL).127651-

Determination of fumonisin B1 levels in body fluids and hair from piglets fed fumonisin B -contaminated diets

The levels of fumonisin B1 (FB1) residues in plasma, urine, feces and hair from 24 piglets fed FB1-contaminated diets containing 3.1, 6.1 or 9.0 μg FB1.g-1 for 28 days were determined using liquid chromatography coupled to mass spectrometry (LC-MS/MS). The levels of FB1 in plasma, urine, feces and pooled hair (n = 3) samples varied from 0.15 to 1.08 μg.L-1, 16.09-75.01 μg.L-1, 1.87-13.89 μg.g-1 and 2.08-8.09 ng.g-1, respectively. Significant correlations (r = 0.808-0.885; P 14 days). The possibility to evaluate hair as a biomarker of fumonisin exposure was established, although further studies are needed to provide physiologically based toxicokinetics of residual FB1 in the pig hair