research article effects of water quality on dissolution...

Research ArticleEffects of Water Quality on Dissolution of YerbaMate Extract Powders

Wen-Ying Huang1 Pei-Chi Lee1 Jaw-Cherng Hsu2 Yu-Ru Lin1

Hui-Ju Chen1 and Yung-Sheng Lin1

1 Department of Applied Cosmetology and Master Program of Cosmetic Science Hungkuang University Taiwan BoulevardShalu District Taichung 43302 Taiwan

2Department of Cosmetic Science National Tainan Junior College of Nursing West Central Tainan 70043 Taiwan

Correspondence should be addressed to Yung-Sheng Lin linyssunrisehkedutw

Received 28 November 2013 Accepted 7 January 2014 Published 24 February 2014

Academic Editors A Berthod and A Sabarudin

Copyright copy 2014 Wen-Ying Huang et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Yerba mate tea is known as one of the most popular nonalcoholic beverages favoured by South Americans due to its nutritionfacts and medicinal properties The processing of yerba mate tea is found to affect the properties of its final forms This studypresents an investigation into the effects of water sources on the dissolution of yerba mate extract powders Comparisons wereconducted between yerba mate teas prepared by dissolving yerba mate extract powders into tap water and deionized water Topicsto be explored in this work are the major compositions and antioxidant activities including total phenol content reducing powerDPPH scavenging activity and ABTS+∙ scavenging capacity It is indicated that there is little difference for antioxidant activities andmajor constituents of yerba mate teas between both water sources However a deeper color is seen in the tap water case resultingfrom the reaction between tannic acid and ionsThis research finding can be treated as a way to benefit the yerbamate tea processingfor applications

1 Introduction

Yerba mate (Ilex paraguariensis) a traditional crop is knownas one of the most popular beverages in Argentina BrazilParaguay and Uruguay [1] As a nonalcoholic beveragefavoured by South Americans [2] yerba mate provides agreat number of bioactive compounds for nutritional andmedicinal applications On account of its alleged therapeuticcapacity yerba mate is found to have hypocholesterolemichepatoprotective and diuretic properties and can resistagainst the deleterious effect of free radicals thus boostingthe defense system of organisms [3ndash8] Furthermore it canas well improve the cardiovascular system in a human body[9ndash11]

Polyphenols (chlorogenic acid) and xanthines (caffeineand theobromine) rank the top 2 places in the sorting by thelevel of active phytochemicals contained in yerba mate tea[8 12] The antioxidant activity of the phenolic compoundsis mainly due to the redox properties thereof which enable

them to serve as good reducing agents [13] The considerableantioxidant potential of yerba mate has long been recognizedand shows dependence on many factors involved in teapreparation

Various processing procedures of plant leaves will resultin different tea qualities [14ndash18] There are a number ofpublished studies on the effect of aqueous infusion on yerbamate tea Isolabella et al [1] and Valerga et al [19] made aninvestigation into compound variation during each step of itsindustrial process Linares et al [20] studied the temperatureinfluence on the aqueous infusion of yerba mate In contrastion effects on aqueous infusion of yerbamate have rarely beendescribedAccording to previous reports on green tea [21 22]elements of water are presumed to have some influence onyerba mate tea

In consideration of the demand growth and potentialhealth benefits from drinking yerba mate tea this study isproposed to quantize the ion effects on the dissolution ofyerba mate extract powders Comparisons are conducted

Hindawi Publishing Corporatione Scientific World JournalVolume 2014 Article ID 768742 6 pageshttpdxdoiorg1011552014768742

2 The Scientific World Journal

on the contents of major bioactive components and theantioxidant activities of yerbamate tea prepared by two watersources Results of this study shed light on the effect of yerbamate tea preparation toward a better understanding of the teaquality in its final presentation

2 Materials and Methods

21 Chemicals and Reagents Panted Finomate EFLA 920yerba mate extract was purchased from Frutarom Switzer-land Ltd Wadenswil Switzerland Folin-Ciocalteu reagentwas from Fluka (Neu-Ulm Germany) Iron(III) chloridewas from Riedel-de Haen (Seelze Germany) Tannic acidcaffeine sodium carbonate trichloroacetic acid (TCA)22-diphenyl-1-picrylhydrazyl (DPPH) butylated hydrox-yanisole (BHA) and 221015840-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) were from Sigma (St Louis USA)Potassium persulfate was from Showa Chemical Co (TokyoJapan) Potassium ferricyanide (K

3Fe(CN)

6) was from JT

Baker (Phillipsburg USA) Potassium dihydrogen phosphate(HPLC grade) and phosphoric acid (HPLC grade) werefrom Wako Pure Chemical Industries Ltd (Tokyo Japan)Methanol and acetonitrile (HPLC grade) were from Merck(Darmstadt Germany)

22 Processing of Yerba Mate Tea Yerba mate tea solutionswere prepared at 25∘C by dissolving yerba mate extractpowders into tap water and deionized water respectivelyTheformer was taken from the suburban area of the GreaterTaichung area Taiwan Deionized water was purified with aMilli-Q water system (Millipore Bedford USA) Yerba matetea was prepared by dissolving different amounts of dry yerbamate extract powders in 25mL water Three replicates weremade in each experiment for statistical analysis

23 Total Phenol Content Total phenol content of the yerbamate tea was estimated by a colorimetric assay based on theprocedure described by Kumazawa et al [23] The 01mLof yerba mate tea solution (100sim500 ppm) was mixed with05mL of Folin-Ciocalteu reagent for a duration of 1 minuteand 05mL of 2 sodium carbonate for 20 minutes Theabsorbance at 655 nm (Sunrise ELISA plate reader TecanAustria) increases with the total phenol content

24 Reducing Power The reducing power of yerba matetea was examined using a mixture of 1mL of phosphatebuffer (02M pH 66) 1mL of potassium ferricyanide (1by weight) and 1mL of tested sample [24] The mixture wasincubated at 50∘C for 20 minutes and a 1mL volume of TCA(1 by weight) was then added to the mixture The TCA-reacted solution (04mL) was mixed with deionized water(05mL) and FeCl

3(1mL 01 by weight) for 10minutes and

the absorbance was measured at 700 nmRelative reducing power () is defined as relative reduc-

ing power = (119860119861) times 100 where 119860 denotes the sampleabsorbance and 119861 the absorbance of 05mgmL BHA

25 DPPH Scavenging Activity TheDPPH scavenging abilityassay was prepared as in Zhang and Wang [25] A 01mL ofsample was mixed with 10mL of 025mMDPPH and 04mLof ethanol incubated for 30minutes in the darkWhenDPPHreacted with an antioxidant that can donate hydrogen itappeared in reduced form and resulted in an absorbance dropat 517 nm (Sunrise ELISA plate reader Tecan Austria) TheDPPH scavenging activity is defined as follows

DPPH scavenging activity ()

= (1 minus

119860517

of sample119860517

of control) times 100

(1)

where the control denotes the water not containing yerbamate tea

26 ABTS+∙ Scavenging Capacity The ABTS+∙ scavengingcapacity assay was carried out using the procedure describedin Erkan et alrsquos method [26] In brief ABTS+∙ was generatedby the reaction of 7mM of ABTS with 245mM of potassiumpersulfate in the dark for 16 hours at 4∘C The 10 120583L of yerbamate tea sample was added to 2mL of ABTS+∙ radical solu-tion for a reaction time of 10 minutes Given the absorbanceat 734 nm the ABTS+∙ radical scavenging activity is definedas

ABTS+ ∙ radical scavenging ()

= (1 minus

119860734

of sample119860734


(2)

where the control represents the water not containing yerbamate tea

27 High Performance Liquid Chromatography Eachextracted yerba mate tea sample was mixed (1 1 vv) witha gallic acid solution (internal standard 20mgL in 70methanol) Subsequently all the samples were spiked withvarious concentrations of stock solutions (theobromine3125 357 417 833 and 125 120583gmL chlorogenic acid7143 833 10 1667 and 25120583gmL caffeine 5 625 83310 and 15625120583gmL) in advance of the HPLC analysis A20120583L of these solutions was injected twice by the HPLCmethod respectively and the standard curves were plottedaccording to the peak areas versus concentrations Recoverywas determined by the comparison between the amounts ofmarker-substances added and found The detection limitsarise from a minimum signal to noise (119878119873) ratio of 3 TheHPLC system (Agilent 1200 infinity series Agilent USA)is equipped with a quaternary pump an autosampler avacuum degasser and a diode array detector A reversephase column (Cosmosil 5C18-AR II 5 120583m 25 cm times 46mmID Nacalai Tesque Kyoto Japan) was used The mobilephase was a mixture of A (10mM KH

2PO4 pH 40) and

B [CH3CN CH

3OH H

2O = 15 25 1 (vvv)] The initial

mobile phase composition was 20 of B After 20minthe mobile phase composition turned into 30 of B After40min the mobile phase composition further turned into50 of B The flow rate was 08mLmin The detector wasoperated at a detection wavelength of 280 nm

The Scientific World Journal 3

Figure 1 Color appearance comparison between yerba mate teasolutions A and C are prepared with tap water and B and D are withdeionized water A and B have a tea concentration of 100 ppm whileC and D have 500 ppm

3 Results and Discussion

31 Solution Appearance Figure 1 indicates the appearanceof yerba mate tea solution placed in quartz cuvettes Assuch the color darkens as the concentration of yerba matetea rises A concentrated solution (500 ppm C and D inFigure 1) demonstrates a deeper color than a diluted one(100 ppm A and B in Figure 1) At the same level of teaconcentration yerba mate tea prepared with tap water showsa darker orange color than prepared with deionized waterThe color difference is presumed to reflect ion chelation withthe composition of yerba mate tea

For a further investigation into the color differencebetween yerba mate teas prepared with different watersources the issue of dissolution of tannic acid a compoundcontained in yerba mate tea is addressed Figure 2 shows thecolor comparison between the tannic acid solutions preparedwith tap water and deionized waterThere is a deeper color inthe tap water than in the deionized water case an event thatmay be attributed to the ion chelating between tannic acidand metal ions in tap water

32 Total Phenol Content Phenols are regarded as the signif-icant constituents of yerba mate tea and the concentrationthereof is directly proportional to the absorbance at 655 nm(119860655

) in Folin-Ciocalteu reaction Figure 3 is a plot of 119860655

versus the yerba mate tea concentration where the yerbamate tea concentration is directly reflected by the total phenolcontents Yet there is little difference in119860

635between the tap

water and the deionized water cases meaning that the totalphenol content is marginally affected by the choice of watersources

33 Reducing Power The reducing power of a compound isseen as a measure of antioxidant activity Figure 4 exhibitsthe reducing power comparison between both test casesA 05mgmL BHA solution was used as a reference in the

Figure 2 Color comparison between tannic acid solutions at a250 ppm concentration prepared with tap water (A) and deionizedwater (B)

0

02

04

06

08

0 100 200 300 400 500 600

Abso

rban

ce

Yerba mate tea concentration (ppm)

Tap waterDeionized water

Figure 3 Comparison of the total phenol content versus theconcentration of yerba mate tea

reducing power measurement As it turns out there is anearly linear relationship between the reducing power andtea concentration even at a tea concentration of 500 ppm(724 plusmn 98 versus 7638 plusmn 927) and a good agreementbetween both samples

34 DPPH Scavenging Activity As a stable free radical com-pound DPPH has been widely adopted as a measure of freeradical scavenging activity This reduction can be monitoredat 517 nm by measuring the bleaching of a violet DPPH solu-tion Figure 5 shows the DPPH radical scavenging activityof yerba mate tea There is a dose-dependent relationshipbetween the DPPH scavenging activity and the concentrationof yerba mate tea and a high consistency between bothtest samples over the while observation Respective 50DPPH radical scavenging activities (IC

50) are observed at tea

concentrations of 413 and 411 ppm in the tap water and thedeionized water cases Hence the DPPH scavenging activityshows no dependence on the ion concentrations of water


0

20

40

60

80

100

0 100 200 300 400 500 600Yerba mate tea concentration (ppm)


Redu

cing

pow

er

( o

f 05

mg

mL

BHA

)

Figure 4 Comparison of the reducing power versus the concentra-tion of yerba mate tea

0

10

20

30

40

50

60

70

0 100 200 300 400 500 600

DPP

H sc

aven

ging

activ

ity (

)



Figure 5 Comparison of the DPPH scavenging activity versus theconcentration of yerba mate tea

35 ABTS+∙ Scavenging Activity ABTS+∙ scavenging activ-ity is another indicator used to test antioxidant activ-ity of yerba mate tea Figure 6 reveals a dose-dependentABTS+∙ radicals scavenging activity for yerba mate teaABTS+∙ radicals were inhibited by 1997plusmn094 and 2164plusmn231 at a tea concentration of 500 ppm in the tap waterand the deionized water cases respectively As the DPPHscavenging activity was discussed in the preceding sectionresults in Figure 6 demonstrate no dependence on the choiceof water sources

36 High Performance Liquid Chromatography As a prereq-uisite for the establishment of calibration curves the peak-area ratios are plotted against the tea concentrations All theregression lines were linear over the concentration range of

0

5

10

15

20

25

30



ABT

S+∙

scav

engi

ng ac

tivity

()

Figure 6 Comparison of the ABTS+∙ scavenging activity versus theconcentration of yerba mate tea

Table 1 Three major components contained in yerba mate teasprepared with distinct water solutions

Water solution Theobromine(mgg)

Chlorogenic acid(mgg)

Caffeine(mgg)

Deionized water 45873plusmn0660 58186 plusmn 0542 43865plusmn2486Tap water 48403plusmn0845 58018 plusmn 1161 45180plusmn0829

interest that is 119910 = 579903119909 + 00296 (1198772 = 09983) fortheobromine 119910 = 97442119909 + 00525 (1198772 = 09998) forchlorogenic acid and 119910 = 12015119909 + 00787 (1198772 = 09941)for caffeine The respective detection limits (119878119873 = 3) forthe components were 0357 (theobromine) 0714 (chorogenicacid) and 0412 (caffeine) 120583gmL Appropriate amounts ofmarker substances (theobromine 625 120583gmL chorogenicacid 125 120583gmL and caffeine 125 120583gmL) were added toa sample containing a known content and the mixtureswere then analyzed by the proposed HPLC approach Therecoveries of the components are sorted in descending orderthat is 10469 9909 and 9106 for theobromine chorogenicacid and caffeine respectively

Substituting the peak-area ratios of the individual peaksfor 119910 in the above-stated equations gives the contents ofthe individual components in the yerba mate tea Tabulatedin Table 1 was a comparison of the average amounts ofthe three aforementioned constituents contained in samplesbetween both water cases It is found that both cases containcomparable amounts of constituents

Previous studies reported that mineralisation of waterhindered tea leaves extraction of organic matter due to thecomplex formation [27 28] The work presents an investi-gation into the influence of water ions on the dissolution ofyerbamate extract powders Unlike the extractions of organicmatters from tea leaves the research findings indicate littledifferences in the compositions as well as the functional char-acteristics between yerba mate teas prepared by dissolving


yerba mate extract powders into tap water and deionizedwater

4 Conclusions

A difference in color appearance is seen between yerba mateteas prepared with tap water solution and deionized waterThe deep color in a tap water case may be attributed to theion chelating between tannic acid and metal ions containedin tap water Analysis of high performance liquid chro-matography and antioxidant experiments including totalphenol content reducing power DPPH scavenging activityand ABTS+∙ scavenging activity reveals that yerba mate teascontain identical compositions and provide the same levelof antioxidant activities irrespective of the choice of watersourcesThis finding can be useful for the processing of yerbamate

Conflict of Interests

Theauthors declare that they have no competing interests Allthe authors have no financial relation with the commercialidentities mentioned in the paper

Acknowledgments

This work was supported by a grant from National ScienceCouncil Taiwan (NSC 102-2632-B-241-001-MY3)

References

[1] S Isolabella L Cogoi P Lopez C Anesini G Ferraro and RFilip ldquoStudy of the bioactive compounds variation during yerbamate (Ilex paraguariensis) processingrdquo FoodChemistry vol 122no 3 pp 695ndash699 2010

[2] E Small and P M Catling ldquoBlossoming treasures of bio-diversity 3 Mate (Ilex paraguariensis)-better than Viagramarijuana and coffeerdquo Biodiversity vol 2 pp 26ndash27 2001

[3] R Filip S B Lotito G Ferraro and C G Fraga ldquoAntioxidantactivity of Ilex paraguariensis and related speciesrdquo NutritionResearch vol 20 no 10 pp 1437ndash1446 2000

[4] R Filip P Lopez G Giberti J Coussio and G FerraroldquoPhenolic compounds in seven South American Ilex speciesrdquoFitoterapia vol 72 no 7 pp 774ndash778 2001

[5] R Filip and G E Ferraro ldquoResearching on new species ofldquoMaterdquo Ilex brevicuspis phytochemical and pharmacologystudyrdquo European Journal of Nutrition vol 42 no 1 pp 50ndash542003

[6] C Anesini G Ferraro and R Filip ldquoPeroxidase-like activity ofIlex paraguariensisrdquo Food Chemistry vol 97 no 3 pp 459ndash4642006

[7] G Colpo F Trevisol A M Teixeira et al ldquoIlex paraguariensishas antioxidant potential and attenuates haloperidol-inducedorofacial dyskinesia and memory dysfunction in ratsrdquo Neuro-toxicity Research vol 12 no 3 pp 171ndash180 2007

[8] F Martins A J Suzan S M Cerutti et al ldquoConsumptionof mate tea (Ilex paraguariensis) decreases the oxidation ofunsaturated fatty acids in mouse liverrdquo British Journal ofNutrition vol 101 no 4 pp 527ndash532 2009

[9] G R Schinella G Troiani V Davila P M De Buschiazzoand H A Tournier ldquoAntioxidant effects of an aqueous extractof Ilex paraguariensisrdquo Biochemical and Biophysical ResearchCommunications vol 269 no 2 pp 357ndash360 2000

[10] A LMosimannDWilhelm-Filho andE LDa Silva ldquoAqueousextract of Ilex paraguariensis attenuates the progression ofatherosclerosis in cholesterol-fed rabbitsrdquo BioFactors vol 26no 1 pp 59ndash70 2006

[11] B B Strassmann A R Vieira E L Pedrotti H N F Morais PF Dias and M Maraschin ldquoQuantitation of methylxanthinicalkaloids and phenolic compounds in mate (Ilex paraguar-iensis) and their effects on blood vessel formation in chickembryosrdquo Journal of Agricultural and Food Chemistry vol 56no 18 pp 8348ndash8353 2008

[12] C I Heck and E G deMejia ldquoYerbamate tea (Ilex paraguarien-sis) a comprehensive review on chemistry health implicationsand technological considerationsrdquo Journal of Food Science vol72 no 9 pp R138ndashR151 2007

[13] A K Atoui A Mansouri G Boskou and P Kefalas ldquoTea andherbal infusions their antioxidant activity and phenolic profilerdquoFood Chemistry vol 89 no 1 pp 27ndash36 2005

[14] Y Huang J Sheng F Yang and Q Hu ldquoEffect of enzymeinactivation by microwave and oven heating on preservationquality of green teardquo Journal of Food Engineering vol 78 no2 pp 687ndash692 2007

[15] V R Sinija H N Mishra and S Bal ldquoProcess technology forproduction of soluble tea powderrdquo Journal of Food Engineeringvol 82 no 3 pp 276ndash283 2007

[16] D Komes D Horzic A Belscak K K Ganic and I VulicldquoGreen tea preparation and its influence on the content ofbioactive compoundsrdquo Food Research International vol 43 no1 pp 167ndash176 2010

[17] X Jun S Deji L Ye and Z Rui ldquoComparison of in vitroantioxidant activities and bioactive components of green teaextracts by different extraction methodsrdquo International Journalof Pharmaceutics vol 408 no 1-2 pp 97ndash101 2011

[18] J Hu Y Chen and D Ni ldquoEffect of superfine grinding onquality and antioxidant property of fine green tea powdersrdquoLWT-Food Science and Technology vol 45 no 1 pp 8ndash12 2012

[19] J Valerga M Reta and M C Lanari ldquoPolyphenol input tothe antioxidant activity of yerba mate (Ilex paraguariensis)extractsrdquo LWT-Food Science and Technology vol 45 no 1 pp28ndash35 2012

[20] A R Linares S L Hase M L Vergara and S L ResnikldquoModeling yerba mate aqueous extraction kinetics influence oftemperaturerdquo Journal of Food Engineering vol 97 no 4 pp 471ndash477 2010

[21] D R Zhou Y Q Chen and D J Ni ldquoEffect of water quality onthe nutritional components and antioxidant activity of green teaextractsrdquo Food Chemistry vol 113 no 1 pp 110ndash114 2009

[22] M S Bae and S C Lee ldquoEffect of deep sea water on theantioxidant activity and catechin content of green teardquo Journalof Medicinal Plant Research vol 4 no 16 pp 1662ndash1667 2010

[23] S Kumazawa M Taniguchi Y Suzuki M Shimura M Kwonand T Nakayama ldquoAntioxidant activity of polyphenols in carobpodsrdquo Journal of Agricultural and Food Chemistry vol 50 no 2pp 373ndash377 2002

[24] Y S Shyu J T Lin Y T Chang C J Chiang and D J YangldquoEvaluation of antioxidant ability of ethanolic extract from dill(Anethum graveolens L) flowerrdquo Food Chemistry vol 115 no 2pp 515ndash521 2009


[25] Y Zhang and Z H Wang ldquoPhenolic composition and antiox-idant activities of two Phlomis species a correlation studyrdquoComptes Rendus vol 332 no 9 pp 816ndash826 2009

[26] N Erkan G Ayranci and E Ayranci ldquoAntioxidant activities ofrosemary (Rosmarinus Officinalis L) extract blackseed (Nigellasativa L) essential oil carnosic acid rosmarinic acid andsesamolrdquo Food Chemistry vol 110 no 1 pp 76ndash82 2008

[27] A Mossion M Potin-Gautier S Delerue I Le Hecho and PBehra ldquoEffect of water composition on aluminium calcium andorganic carbon extraction in tea infusionsrdquo Food Chemistry vol106 no 4 pp 1467ndash1475 2008

[28] W Y Huang Y R Lin R F Ho H Y Liu and Y S Lin ldquoEffectsof water solutions on extracting green tea leavesrdquoThe ScientificWorld Journal vol 2013 Article ID 368350 6 pages 2013

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


on the contents of major bioactive components and theantioxidant activities of yerbamate tea prepared by two watersources Results of this study shed light on the effect of yerbamate tea preparation toward a better understanding of the teaquality in its final presentation

2 Materials and Methods

21 Chemicals and Reagents Panted Finomate EFLA 920yerba mate extract was purchased from Frutarom Switzer-land Ltd Wadenswil Switzerland Folin-Ciocalteu reagentwas from Fluka (Neu-Ulm Germany) Iron(III) chloridewas from Riedel-de Haen (Seelze Germany) Tannic acidcaffeine sodium carbonate trichloroacetic acid (TCA)22-diphenyl-1-picrylhydrazyl (DPPH) butylated hydrox-yanisole (BHA) and 221015840-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) were from Sigma (St Louis USA)Potassium persulfate was from Showa Chemical Co (TokyoJapan) Potassium ferricyanide (K

3Fe(CN)

6) was from JT

Baker (Phillipsburg USA) Potassium dihydrogen phosphate(HPLC grade) and phosphoric acid (HPLC grade) werefrom Wako Pure Chemical Industries Ltd (Tokyo Japan)Methanol and acetonitrile (HPLC grade) were from Merck(Darmstadt Germany)

22 Processing of Yerba Mate Tea Yerba mate tea solutionswere prepared at 25∘C by dissolving yerba mate extractpowders into tap water and deionized water respectivelyTheformer was taken from the suburban area of the GreaterTaichung area Taiwan Deionized water was purified with aMilli-Q water system (Millipore Bedford USA) Yerba matetea was prepared by dissolving different amounts of dry yerbamate extract powders in 25mL water Three replicates weremade in each experiment for statistical analysis

23 Total Phenol Content Total phenol content of the yerbamate tea was estimated by a colorimetric assay based on theprocedure described by Kumazawa et al [23] The 01mLof yerba mate tea solution (100sim500 ppm) was mixed with05mL of Folin-Ciocalteu reagent for a duration of 1 minuteand 05mL of 2 sodium carbonate for 20 minutes Theabsorbance at 655 nm (Sunrise ELISA plate reader TecanAustria) increases with the total phenol content

24 Reducing Power The reducing power of yerba matetea was examined using a mixture of 1mL of phosphatebuffer (02M pH 66) 1mL of potassium ferricyanide (1by weight) and 1mL of tested sample [24] The mixture wasincubated at 50∘C for 20 minutes and a 1mL volume of TCA(1 by weight) was then added to the mixture The TCA-reacted solution (04mL) was mixed with deionized water(05mL) and FeCl

3(1mL 01 by weight) for 10minutes and

the absorbance was measured at 700 nmRelative reducing power () is defined as relative reduc-

ing power = (119860119861) times 100 where 119860 denotes the sampleabsorbance and 119861 the absorbance of 05mgmL BHA

25 DPPH Scavenging Activity TheDPPH scavenging abilityassay was prepared as in Zhang and Wang [25] A 01mL ofsample was mixed with 10mL of 025mMDPPH and 04mLof ethanol incubated for 30minutes in the darkWhenDPPHreacted with an antioxidant that can donate hydrogen itappeared in reduced form and resulted in an absorbance dropat 517 nm (Sunrise ELISA plate reader Tecan Austria) TheDPPH scavenging activity is defined as follows

DPPH scavenging activity ()

= (1 minus

119860517

of sample119860517


(1)

where the control denotes the water not containing yerbamate tea

26 ABTS+∙ Scavenging Capacity The ABTS+∙ scavengingcapacity assay was carried out using the procedure describedin Erkan et alrsquos method [26] In brief ABTS+∙ was generatedby the reaction of 7mM of ABTS with 245mM of potassiumpersulfate in the dark for 16 hours at 4∘C The 10 120583L of yerbamate tea sample was added to 2mL of ABTS+∙ radical solu-tion for a reaction time of 10 minutes Given the absorbanceat 734 nm the ABTS+∙ radical scavenging activity is definedas

ABTS+ ∙ radical scavenging ()

= (1 minus

119860734

of sample119860734


(2)

where the control represents the water not containing yerbamate tea

27 High Performance Liquid Chromatography Eachextracted yerba mate tea sample was mixed (1 1 vv) witha gallic acid solution (internal standard 20mgL in 70methanol) Subsequently all the samples were spiked withvarious concentrations of stock solutions (theobromine3125 357 417 833 and 125 120583gmL chlorogenic acid7143 833 10 1667 and 25120583gmL caffeine 5 625 83310 and 15625120583gmL) in advance of the HPLC analysis A20120583L of these solutions was injected twice by the HPLCmethod respectively and the standard curves were plottedaccording to the peak areas versus concentrations Recoverywas determined by the comparison between the amounts ofmarker-substances added and found The detection limitsarise from a minimum signal to noise (119878119873) ratio of 3 TheHPLC system (Agilent 1200 infinity series Agilent USA)is equipped with a quaternary pump an autosampler avacuum degasser and a diode array detector A reversephase column (Cosmosil 5C18-AR II 5 120583m 25 cm times 46mmID Nacalai Tesque Kyoto Japan) was used The mobilephase was a mixture of A (10mM KH

2PO4 pH 40) and

B [CH3CN CH

3OH H

2O = 15 25 1 (vvv)] The initial

mobile phase composition was 20 of B After 20minthe mobile phase composition turned into 30 of B After40min the mobile phase composition further turned into50 of B The flow rate was 08mLmin The detector wasoperated at a detection wavelength of 280 nm









635between the tap




0

02

04

06

08

0 100 200 300 400 500 600

Abso

rban

ce









0

20

40

60

80

100



Redu

cing

pow

er

( o

f 05

mg

mL

BHA

)


0

10

20

30

40

50

60

70

0 100 200 300 400 500 600

DPP

H sc

aven

ging

activ

ity (

)






0

5

10

15

20

25

30



ABT

S+∙

scav

engi

ng ac

tivity

()





Caffeine(mgg)







4 Conclusions




Acknowledgments


References







































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of









635between the tap




0

02

04

06

08

0 100 200 300 400 500 600

Abso

rban

ce









0

20

40

60

80

100



Redu

cing

pow

er

( o

f 05

mg

mL

BHA

)


0

10

20

30

40

50

60

70

0 100 200 300 400 500 600

DPP

H sc

aven

ging

activ

ity (

)






0

5

10

15

20

25

30



ABT

S+∙

scav

engi

ng ac

tivity

()





Caffeine(mgg)







4 Conclusions




Acknowledgments


References







































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


0

20

40

60

80

100



Redu

cing

pow

er

( o

f 05

mg

mL

BHA

)


0

10

20

30

40

50

60

70

0 100 200 300 400 500 600

DPP

H sc

aven

ging

activ

ity (

)






0

5

10

15

20

25

30



ABT

S+∙

scav

engi

ng ac

tivity

()





Caffeine(mgg)







4 Conclusions




Acknowledgments


References







































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



4 Conclusions




Acknowledgments


References







































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of















Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

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