research article quality attributes of fresh-cut coconut after supercritical carbon...

Hindawi Publishing CorporationJournal of ChemistryVolume 2013 Article ID 703057 9 pageshttpdxdoiorg1011552013703057

Research ArticleQuality Attributes of Fresh-Cut Coconut after SupercriticalCarbon Dioxide Pasteurization

Giovanna Ferrentino1 Ana Belscak-Cvitanovic2 Drazenka Komes2 and Sara Spilimbergo1

1 Department of Materials Industrial Engineering University of Trento Via Mesiano 77 38123 Trento Italy2 Department of Food Engineering Faculty of Food Technology and Biotechnology University of Zagreb Pierottijeva 610 000 Zagreb Croatia

Correspondence should be addressed to Sara Spilimbergo saraspilimbergoingunitnit

Received 11 February 2013 Accepted 21 May 2013

Academic Editor Marleny D A Saldana

Copyright copy 2013 Giovanna Ferrentino 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

The impact of supercritical CO2(SC-CO

2) process on the quality attributes of fresh-cut coconut has been investigated to establish

the acceptability of SC-CO2treated products by the consumers Two process conditions previously identified as optimal to reduce

themicrobial content of the product were studied 12MPa 40∘C 30min and 12MPa 45∘C 15minThe results highlighted that bothconditions induced some effects on product attributes After 30min of treatment at 12MPa and 40∘C a decrease of lightness (8)pH (13) fat content (24) total phenol content (29) flavonoid compounds (49) antioxidant capacity (30) and an increase ofdrymatter (11) and titratable acidity (511)were observedwhile polyphenol oxidase (PPO) exhibited 35 and 985 inactivationPeroxidase enzyme activity increased by 778 and 304 at 12MPa 40∘C 30min and 12MPa 45∘C 15min respectively Sensoryevaluations revealed no significant differences in appearance texture taste and aroma of treated fresh-cut coconut compared tothe untreated The study confirms the feasibility of SC-CO

2process for the pasteurization of fresh fruits with a firm structure and

opens the door to the possibility of exploiting such a technology at industrial level

1 Introduction

Fresh-cut fruits and vegetables fresh raw products are proc-essed to supply ready-to-eat or ready-to-use foods [1 2]Theyare becoming popular within the consumers who demandhygienically safe [3] and economically convenient productswith fresh-like characteristics Coconut (Cocos nucifera L)prepared as fresh-cut fruit to be eaten and served as asnack is gaining great appeal however the operations forits production such as cutting and washing could fasten themicrobial growth and accelerate enzymesrsquo actions shorteningits shelf-life in comparison with the fresh product [4] Toavoid or retard microbial and enzymatic spoilage of theproduct reducing or minimally compromising its qualityaspects while maintaining a fresh appearance its originalflavor and texture several treatments are currently underinvestigation such as sodium chloride treatments [5] steamblanching [6] immersion in acid or basic solutions [7] anduse of modified atmosphere packaging [8]

Supercritical carbon dioxide (SC-CO2) is a promising

alternative process potentially able to inactivate microorgan-isms and enzymes in liquid foods with minimal effects onphytochemicals and organoleptic characteristics The mainadvantage of the technique consists of the relatively low tem-perature which avoids the thermal effects of the traditionalheat pasteurization retaining the food freshness in terms ofphysical nutritional and sensory qualities [9] Concerningsolid foods the research is still at its infancy few papers havebeen published so far in the field [10] A deleterious effectin terms of gross tissue destruction on strawberries honey-dew melon cucumber [11] and pear [12] which negativelyinfluenced product aspect discouraging the application ofthe technology to products with soft structures was reportedDifferently Ji et al [13] demonstrated that shrimps CO

2pro-

cessed gained a cooked appearance positively accepted by thepanelists and proved that these changes could be attractivefor shrimps consumption in the Chinese diet custom Theirfindings demonstrated that modifications of the product

2 Journal of Chemistry

appearance could not be a restraint but an improvement inthe development of an innovative pasteurization techniquedepending on people and cultural habits

As concerns fresh-cut coconut one study has beenrecently published to assess the effectiveness of SC-CO

2as

nonthermal technique for the pasteurization of such a prod-uct assuring its microbial safety The results clearly demon-strated the potential of SC-CO

2pasteurization of fresh-

cut coconut which significantly reduced total mesophilicmicroorganisms total coliforms yeasts andmolds and lacticacid bacteria naturally present on its surface The optimalprocess conditions identified were 12MPa 40∘C 30min and12MPa 45∘C 15min at which 4 Log(CFUg) reductions wereachieved for the mentioned microbial strains [14]

At this stage the investigation of the impact of suchtechnology on the quality attributes of the product is neededin view of a possible development of SC-CO

2process at

industrial scale In this concern the aim of the present studyis the evaluation of the effects of SC-CO

2process on the

quality attributes of fresh-cut coconut in terms of colorpH titratable acidity (TA) fat content dry matter (DM)indigenous enzyme activity total phenol content (TPC)flavonoid compounds (FC) antioxidant capacity and sensoryattributes (aroma taste appearance and texture)

2 Materials and Methods

21 Sample Preparation Coconut (Cocos nucifera) was pur-chased from a local market deshelled cleaned washedwith water and manually cut in pieces The samples weretransferred into the reactor and treated at 12MPa 40∘C for30min and 12MPa 45∘C for 15min The process conditionswere chosen on the basis of the previous study on microbialinactivation [14] they assured the highest pasteurizing effect(47 log reductions of mesophilic microorganisms 26 logreductions of lactic bacteria 46 log reductions of totalcoliforms and 32 log reductions of yeasts and molds) on thenatural microbial flora occurred on fresh-cut coconut

22 High Pressure Carbon Dioxide Equipment SC-CO2

treatment was performed in the batch apparatus shownin Figure 1 Liquid CO

2(99990 purity Messer Group

GmbH Germany) was fed into a high pressure vessel by avolumetric pump (LCD1M910s LEWA GmbH Germany)with a maximum flow rate of 11 lh The vessel consistedof a 310mL stainless steel cylinder (height 110mm innerdiameter 60mm) and was equipped with a resistance tem-perature probe (Pt 1001015840Ω Endress+Hauser Milano Italy)and a pressure gauge (Gefran Brescia Italy) The sample wasloaded into the vessel heated to a defined temperature andsubsequently pressurized with CO

2 The system was kept at

the process conditions of temperature and pressure for thetime required for the treatment and then slowly depressur-ized Pressure and temperature were continuously recorded

by a real time data acquisition system (field point FP-1000RS 232RS 485 NATIONAL INSTRUMENTS Austin TexasUSA) and monitored by a specific software (LabVIEW 50)Thedepressurization stepwas performedby partially openingtwo micrometric valves (2S-4L-N-SS Rotarex Brescia Italy)placed on the output line of the system heated with anelectrical resistance (80W CSC2 Backer Fer Ferrara Italy)to prevent CO

2freezing during the expansion to ambient

pressure After each experimental run the reactor waswashed with water and sterilized in autoclave (121∘C 15min)to prevent possible contaminations while CO

2was flushed at

6 MPa through all tubes to ensure a good level of cleaning

23 Color Measurements Color parameters were measuredwith a high resolution miniature spectrometer (HR2000+Ocean Optics Inc Dunedin FL) to which a fiber opticreflection probe (QR600-7-UV-125BX Ocean Optics IncDunedin FL) was connectedThe probe transmitted the lightfrom a halogen lamp to the sample surface by the illuminatingfibers while the reflected light from the sample was acquiredby a reading fiber and measured by the spectrometer Aftercalibration the samplewas placed on a holding device and thesignal acquired by a specific software (Spectra Suite OceanOptics Dunedin FL USA) which provides Llowast(lightness)alowast(redness) and blowast(yellowness) parameters Color analyseswere performed on samples treated three times at the sameprocess conditions and the mean values together with thestandard deviations reported Additionally in order to quan-tify the overall color differences Δ119864 values were evaluatedbased on the following equation [15]

Δ119864 = radic(119871lowast

1minus 119871lowast

2)2

+ (119886lowast

1minus 119886lowast

2)2

+ (119887lowast

1minus 119887lowast

2)2

(1)

where Llowast alowast and 119887lowast with subscript numbers representlightness redness and yellowness measured before and aftertreatments respectively More details of the procedure can befound elsewhere [16]

24 pH Determination The sample (30 grams) was homoge-nized with 30mL of distilled water and the pH was measuredusing a digital pH meter (Eutech Instruments NijkerkThe Netherlands) after calibration with commercial buffersolutions at pH 70 and 40 The measurements in triplicatefor each condition were performed recording the pH of10mL of the homogenized solutions

25 Titratable Acidity Measurements 10mL of a solutionobtained from the sample (30 grams) homogenized with30mL of distilled water was titrated against standardizedNaOH (005N) to the phenolphthalein end point (pH = 82plusmn01) The volume of NaOH was converted to grams of lauricacid (considered the prevalent acid in fresh-cut coconut) permL of the homogenized solution and titratable acidity (TA)calculated based on the following formula

TA (lauric acid gL) =(mL NaOH used) sdot (Normality of NaOH) sdot (Molecular weight of lauric acid)

mL homogenized sample (2)

Journal of Chemistry 3

Data acquisition

PTT

Thermostatic bath

Vessel

Filter

Pump

PI

PI

V4V3R2

V1 Heatexchanger

R1V2

CO2 tank

Figure 1 Schematic of the SC-CO2apparatus V1 to V4 valves R1 R2 electrical resistance PT pressure transducer T thermocouple PI

pressure manometer

Measurements were performed in triplicate and mean valuesand standard deviations were evaluated

26 Dry Matter Content Dry matter (DM) was determinedaccording to the official AOAC method [17] by drying thesamples at 105∘C to reach a constant weight The dry mattercontent measured as the remaining weight of sample afterdrying was expressed as percentage of the fresh sample

27 Determination of Phenolic Compounds andAntioxidant Capacity

271 Preparation of the Samples Fresh-cut coconut endocarpand mesocarp were ground in a domestic blender and driedin a conventional laboratory dryer for 3 hrs at 60∘C In orderto eliminate lipids each sample was subjected to extractionfor 48 hrs with petroleum ether using a Soxhlet apparatus[18]The defatted samples were air-dried for 24 hrs to removethe residual organic solvent and extracted with 20mL of 50ethanolwater solution (vv) for 1 hr in an ultrasonic bath(Elmasonic S 120 Elma Singen Germany) After extractionthe mixture was centrifuged for 10min at 4000 rpm and thesupernatant was decanted and filtered to remove the residualparticles and obtain 20mL of extract The flask containingthe extract was flushed with nitrogen stored in a freezer atndash18∘C and subsequently analyzed for the determination oftotal phenol content (TPC) and antioxidant capacity

272 Total Phenol and Flavonoid Content Total phenol con-tent (TPC) was determined spectrophotometrically accord-ing to the modified method of Lachman et al [19] Totalflavonoids were precipitated using formaldehyde whichreacted with the hydroxyl groups at the C-6 or C-8 posi-tions in the benzene rings of 57-dihydroxy flavonoids Thecondensed products of these reactions were removed byfiltration and the remaining nonflavonoid phenols deter-mined according to the procedure for total phenol contentdetermination Flavonoid content (FC) was calculated as thedifference between total phenol and nonflavonoid contentGallic acid was used as standard and the results wereexpressed as mg gallic acid equivalents (GAE)g of DM [20]

All measurements were performed in triplicate and meanvalues and standard deviations were evaluated

273 HPLC Analysis of Phenolic Compounds Coconutextracts were analyzed for their phenolic acids contentaccording to the IOOC [21]methodwith somemodificationsThe samples were filtered through a 045 120583m filter (NylonMembranes Supelco Bellefonte USA) and 20120583L were ana-lyzed using a HPLC device (Agilent 11001200 Series SantaClara USA) with a Diode Array detector (scanning between200 and 400 nm with a resolution of 12 nm) and a reversed-phase column (250times 46mm 5 120583m id) (Nucleosil C-18 Phe-nomenex Torrance USA)The solvents used for the analysesconsisted of 02 orthophosphoric acid (solvent A) HPLCgrade methanol (solvent B) and HPLC grade acetonitrile(solvent C) at a flow rate of 15mLmin The elution wasperformed with a gradient starting from 2 B and 2 C toreach 25 B and 25C in 40min with a column temperatureof 30∘C Chromatograms were recorded at 280 nm Phenoliccompounds were identified by comparing the retention timesand the spectral data with the standards Data acquisitionand elaboration were carried out using a specific software(Chemstat 32 Scientific Software Group Utah USA) All theanalyses were performed in triplicate and mean values andstandard deviations were evaluated

274 Antioxidant Capacity

DPPH Radical Scavenging Assay Antioxidant capacity ofcoconut extracts was determined using the DPPH (120572120572-Diphenyl-120573-picryl-hydrazyl) radical scavenging assay bymeasuring the absorbance at 515 nm after 30min of reactionat room temperature as described by Brand-Williams et al[22] The results were expressed as 120583molg of DM Troloxequivalents using the calibration curve of Trolox (100ndash1000 120583M) All measurements were performed in triplicateand mean values and standard deviations were evaluated

ABTS Radical Scavenging Assay Trolox equivalent antiox-idant capacity (TEAC) of coconut extracts was estimatedby the ABTS (2 21015840-azino-bis(3-ethylbenzothiazoline-6-sul-phonic acid)) radical cation decolourisation assay [23]


The results obtained from triplicate analyses were expressedas Trolox equivalents in 120583molg of DM and were derivedfrom a calibration curve determined for this standard (100ndash1000120583M)

28 Enzymatic Activity Determination

281 Enzyme Extraction Ground coconut (5 grams) wasextracted at 4∘C with a phosphate buffer solution (01MpH 7) containing 5 grams of polyvinylpyrrolidone using amagnetic stirrer for 15min The homogenate was filtered(Whatman No 41 filter paper) centrifuged at 3500 rpm for20min and subsequently the supernatant was filtered again(WhatmanNo 42 filter paper) to collect enzyme extract [24]

282 Polyphenol Oxidase and Peroxidase (PPO and POD)Enzymatic Activity Polyphenol oxidase (PPO) activity wasdetermined using a spectrophotometricmethod based on theincrease in absorbance at 410 nm according to the proceduredescribed by Soliva et al [25] with some modificationsEnzyme extract (50 120583L) wasmixed with 195mL of phosphatebuffer solution and 1mL of catechol (01M) in a 1 cm pathlength cuvette The absorbance was continuously recorded at25∘C for 5min

Peroxidase (POD) activity was assayed spectrophotomet-rically at 470 nm using guaiacol as a phenolic substrate withhydrogen peroxide [26] The reaction mixture containing015mL of 4 (vv) guaiacol 015mL of 1 (vv) H

2O2

266mL of phosphate buffer solution and 40120583L of enzymeextract was transferred to a 1 cm path length cuvette for theabsorbance measurements Enzyme activity was reported inenzyme Units (U) defined as the change of 0001 in theabsorbance value per min under the conditions of the assayVolume activity of both enzymes was calculated from theslope of the linear portion of the Δ119860 curve as a function oftime according to the following formula

Va = VT(120576 sdot 119889 sdot VE)

sdotΔ119860

Δ119905 (3)

where VT is for the total volume of the reaction mixtureVE the volume of the extracted enzyme 119889 the cuvettepath length (1 cm) 120576 the molar absorptivity of 4-methyl-quinoline (1010Mminus1cmminus1) for PPO and tetraguaiacol (266 sdot104Mminus1 cmminus1) for POD and Δ119905 the time interval All mea-surements were performed in triplicate and the results wereexpressed as specific activity (Sa) in enzyme units per g ofproduct (Ug)

29 Sensory Analysis Samples were evaluated by a panel of10 untrained judges 5 males and 5 females between 21 and50 years old using a descriptive analysis based on a modifiedprocedure described by Komes et al [27] The evaluationswere conducted the day after the samples preparation in aquiet roomwith sufficient space between the testers adequatelight and ventilation at mid-morning considered the besttime before extraneous aromas and odours fill the air A rankorder test was performed and the panelists were asked to

Untreated

Col

or p

aram

eter

s

minus2

0

2

4

70

80

90

100

aaaa a

ba

a

b

Treated at 12 MPa45

∘C 15 minTreated at 12 MPa40

∘C 30 min

Figure 2 Color parameters of untreated and treated fresh-cutcoconuts lightness 119871lowast light grey 119886lowast dark grey 119887lowast Values withsimilar letters within bars are not significantly different

independently evaluate four sensory characteristics appear-ance texture taste and aroma for each sample presentedin plastic white cups at ambient temperature The volunteerswere asked to judge three samples using a 10-point scale (1corresponded to the lowest preference and 10 to the highest)one untreated and two SC-CO

2fresh-cut coconut treated at

12MPa 40∘C 30min and 12MPa 45∘C 15min respectivelyThe results were expressed as the average for each sensoryattribute with the standard deviations

210 Statistical Analysis Differences between mean valueswere tested using the analysis of variance followed bymultiplecomparisons between means with the Tukeyrsquos StudentizedRange test The general procedure of Statistica 70 software(StatSoft Inc Tulsa OK USA) was used All the data wereanalyzed at a significance level of 119875 gt 005

3 Discussion and Results

31 Color Figure 2 reports color measurements of untreatedand SC-CO

2treated coconuts The results indicated that

alowast and blowast parameters did not significantly change aftertreatments while Llowast significantly decreased in agreementwith Ferrentino et al [16] who found that alowast and blowastmeasuredon coconut samples were approximately zero before and afterprocesses at 12MPa 40∘C for 10 20 and 30min while Llowastsignificantly decreased just after 10min of treatment Colordifferences in terms of Δ119864 were equal to 692 and to 815for samples treated at 12MPa 40∘C 30min and at 12MPa45∘C 15min respectively suggesting that a trained observercould detect visible differences between untreated and SC-CO2treated coconut On the other hand it must be said that

the Δ119864 threshold value often depends on the type of matrix[28]

32 Titratable Acidity and pH Table 1 reports pH and TAvalues of untreated and treated fresh-cut coconuts A slightbut significant pH decrease was observed from 607 to 582and 585 for samples treated at 12MPa 40∘C 30min and at12MPa 45∘C 15min respectively As expected an opposite


Table 1 pH TA DM fat content TPC FC and antioxidant capacity of untreated and SC-CO2 treated coconut

pHTA DM Fat content TPC TFC Antioxidant capacity

(g Lauric AcidL) (mg GAEgDM)

(mg GAEgDM)

ABTS(120583mol

Troloxg DM)

DPPH(120583mol

Troloxg DM)Untreated 607 plusmn 002a 546 plusmn 151a 3911 plusmn 234a 3598 plusmn 258a 150 plusmn 015a 106 plusmn 012a 588 plusmn 104a 626 plusmn 052a

Treated at12MPa 40∘C30min

582 plusmn 002b 825 plusmn 025b 4331 plusmn 171b 2733 plusmn 407b 107 plusmn 031b 054 plusmn 018b 413 plusmn 123b 501 plusmn 063b


585 plusmn 008b 741 plusmn 010c 4277 plusmn 006b 2977 plusmn 089b 095 plusmn 011b 045 plusmn 012b 395 plusmn 028b 479 plusmn 082b

Data are mean values plusmn standard deviations Values with similar letters within rows are not significantly different (119875 gt 005) TA titratable acidity DM drymatter TPC total phenol content TFC total flavonoid content

behavior was recorded for TA values A similar trend hasbeen already reported by other authors for TAmeasurementsperformed on liquid matrices processed by SC-CO

2[29 30]

The increase in acidity could be related to the presence ofCO2dissolved into the liquid phase forming carbonic acid

Data were in agreement with another study on fresh-cutconference pears treated at 10MPa 40∘C 10min whose pHwas unaffected by the treatment while acidity increased [12]

33 Dry Matter and Fat Content DM and fat content ofuntreated and SC-CO

2treated coconut samples are reported

in Table 1 DM of coconut ranged from 3911 plusmn 234 foruntreated coconut to 4331plusmn171and 4277plusmn006 for sam-ples treated at 12MPa 40∘C 30min and 12MPa 45∘C 15minwhile fat content varied from 3598 plusmn 258 for the untreatedto 2733 plusmn 407 and 2977 plusmn 089 for treated samples Asnoticed an opposite trend was observed comparing DM andfat content fresh untreated coconuts were characterized by alower DM and a higher fat content DM increase in treatedproducts could be related to water loss from the samplesduring the treatment while fat content decrease could belinked to CO

2high affinity for lipophilic substances that in

supercritical phase exerts a high extractive power

34 Total Phenol Content Flavonoid Content andAntioxidantCapacity Higher TPC (1495 plusmn 015mg GAEg DM) andFC (1056 plusmn 012mg GAEg DM) were measured in theuntreated coconut compared to the treated one indicatingsome negative effects induced by CO

2on these beneficial

bioactive compounds on average 32 and 53 decrease inTPC and FC was observed after SC-CO

2treatments respec-

tively (Table 1) Additionally also the antioxidant capacitydetermined by bothABTS andDPPH assays decreased in thetreated samples (on average 31 by ABTS and 22 byDPPH)compared to the untreated ones Published studies reportedcontrasting results regarding the effects of SC-CO

2treatment

on total phenol content and antioxidant capacity in foodsPozo-Insfran et al [31] observed no changes in anthocyaninssoluble phenolics and antioxidant capacity of muscadinegrape juice processed by dense phase CO

2at 345MPa 30∘C

for 625min Similar conclusions were drafted by Ferrentinoet al [30] where no effects were observed on TPC of a

red grapefruit juice treated by dense phase CO2(345MPa

40∘C 7min) while slight differences were observed in theascorbic acid content and antioxidant capacity of the juiceafter treatment and after 4 weeks of storage at 4∘C On thecontrary other studies demonstrated that vitamin C contentof pears [12] and betanin and isobetanin contents of red beet[32] significantly decreased leading to the conclusion that SC-CO2treatment differently and selectively affected bioactive

compounds probably depending on the characteristics of thefood product In the present study the decrease of polyphe-nolic compounds of coconut was attributed to the employedcombination of high temperatures and long processing timesof SC-CO

2treatment and to the increase in the food acidity

due to the formation of carbonic acid which contributed tothe modification and lowering contents of these compounds

35 HPLC Determination of Phenolic Compounds As re-ported in Table 2 ferulic acid was the most abundant com-pound detected in the sample (with a content of 6093 plusmn348 120583gg DM in the fresh untreated coconut and of 5669 plusmn320 120583gg DM in the treated one at 12MPa 45∘C 15min)followed by p-coumaric acid (from 5574 plusmn 145 120583ggDM inthe untreated coconut to 4813 plusmn 156 120583gg DM in the treatedone at 12MPa 45∘C 15min) and chlorogenic acid (from1330 plusmn 0035 120583gg DM in the untreated coconut to 1028 plusmn0025 120583ggDM in the treated one at 12MPa 45∘C 15min)The data obtained are in agreement with the ones obtainedby Bankar et al [33] even though in the present studymuch lower concentrations of all polyphenolic compoundswere obtained probably because of differences in coconutvariety degree of ripeness geographical origin or extractiontechnique As a whole from Table 2 it can be observed thatfresh untreated coconut exhibited higher content of totalpolyphenolic compounds compared to treated samples Itcould also be observed that vanillic acid was present onlyin the untreated sample highlighting that CO

2treatments

affected both content and composition of polyphenolic com-pounds Compared to TPC results in Table 1 a much lowercontent of total phenolic acids was measured by HPLCanalysis this result was not surprising since it has been wellestablished that spectrophotometric assays are not selectiveand often overestimate the results [34 35]


Table 2 Phenolic acids content of untreated and treated coconut extracts

Phenolic acids (120583gg DM) TotalSA VA ChlA p-coumA FA

Untreated 4708 plusmn 112a 3176 plusmn 078 1330 plusmn 0035a 5574 plusmn 145a 6093 plusmn 348a 20881Treated at 12MPa 40∘C 30min 5598 plusmn 227b ndlowast 1297 plusmn 0011b 5975 plusmn 265b 5547 plusmn 291a 18417Treated at 12MPa45∘C 15min 5479 plusmn 483b ndlowast 1028 plusmn 0025c 4813 plusmn 156c 5669 plusmn 320a 16989Data are mean values plusmn standard deviations Values with similar letters within rows are not significantly different (119875 gt 005) lowastNot detected SA syringic acidVA vanillic acid ChlA chlorogenic acid p-coumA p-coumaric acid FA ferulic acid

Table 3 Enzymatic activity of untreated and SC-CO2 treated coconut

PPO Activity (Ug) POD activity (Ug)Untreated (10440 plusmn 0001) sdot 10

minus3a(9910 plusmn 1652) sdot 10

minus3a

Treated at 12MPa 40∘C 30min (7594 plusmn 1687) sdot 10minus3b

(17620 plusmn 0001) sdot 10minus3b

Treated at 12MPa 45∘C 15min (0202 plusmn 0081) sdot 10minus3c

(12923 plusmn 0001) sdot 10minus3c

Data are mean values plusmn standard deviations Values with similar letters within rows are not significantly different (119875 gt 005) PPO polyphenol oxidase PODperoxidase

36 Polyphenol Oxidase and Peroxidase Activity PPO andPOD enzymatic activities of untreated and treated coconutsamples are reported in Table 3 As noticed both processconditions induced PPO inactivation 35 and 985 inac-tivation was achieved at 12MPa 40∘C for 30min and at12MPa 45∘C for 15min respectively

According to the results the combination of higher tem-perature (45∘C) and shorter processing time (15min) is highlyeffective to inactivate PPO in coconutThe experimental find-ings are in agreement with Park et al [36] who reported thatPPO activity in carrot juice decreased after a combined highpressure CO

2and high hydrostatic pressure treatment Pozo-

Insfran et al [37] also observed 40 decrease in PPO activityin muscadine grape juice by dense phase CO

2processing

As regards POD an increase of its activity was observedat both process conditions tested as reported in Table 2 PODwas activated by 778 at 12MPa 40∘C 30min and by 304at 12MPa 45∘C 15min However no off-flavors and off-colors of the sample were detected although these enzymesare supposed to be empirically related to the deteriorationof fresh-cut vegetables and fruits [38] Further a storagestudy (4∘C for 4 weeks) of the processed product was alsoperformed and no enzymes reactivation with consequentlysample off-flavors and off-colors was detected probablythanks to the low storage temperature employed in the studythat was chosen considering the final use of the productas ready-to-eat fruit The resistance of POD extracted fromvegetables and fruits has been reported in several studies [39]thermal processes (sim90∘C for 5 s) are needed to induce com-plete inactivation of this enzyme Fricks et al [40] performeda high pressure CO

2treatment on POD extracted from radish

(Raphanus sativus L) suspended in a buffer solution anincrease of the specific activity of this enzyme up to 212 wasobserved at 7MPa 30∘C and 1 hr treatment Further Primo etal [41] evaluated the effects of compressed CO

2treatment on

the specificity of oxidase enzymatic complexes extracted frommate tea leaves they showed that 30∘C 705MPa and 1 hrtreatment led to 25 enhancement of POD activity and 50loss of PPO activity Some literature results also demonstrated

that POD residual activity was closely related to the SC-CO2

applied pressure [42] as the applied pressure was increasedup to 30MPa the enzyme residual activity was reduceddown to 12 indicating that the three-dimensional structureof enzymes could be significantly altered under extremeconditions causing their denaturation and a consequent lossof their activity If the conditions are less adverse the proteinstructure could largely be retained Minor structural changescould induce an alternative active protein state with alteredenzyme activity specificity and stability [43]However to ourknowledge clear explanations and extensive investigations onthe relationship between the activity of enzymes treated withsupercritical fluids and supercritical operating conditionshave never been provided

37 Sensory Analyses Panelists did not perceive significantdifferences in terms of appearance texture taste and aromaattributes between untreated and treated samples (Table 4)Treated coconuts were judged similar to the fresh one andno losses of product or discoloration of edible parts wereobserved These results differed from the color instrumentalmeasurements here reported where significant differences inLlowast of the untreated and treated samples were detected and inΔ119864 values which indicated high overall color differences

Concerning the texture the panelists could not detectany noticeable differences between untreated and treatedproducts SC-CO

2treated coconuts were judged firm

hard and crispy and ranked sweet and harmonious withno detection of bitter or off-taste These findings are alsosupported by the instrumental measurements performed toevaluate the hardness of fresh-cut coconut processed at thesame SC-CO

2conditions [14] As regards aroma attributes

and coconut like taste the untreated fresh-cut coconutwas rated with low scores indicating a higher panelistsrsquopreference towards the SC-CO

2treated samples Probably

CO2in supercritical state acting in the extraction of volatile

compounds associated to the flavor of fresh-cut coconuthad the ability to enhance the palatability and perception to


Table 4 Sensory evaluations of fresh-cut coconut before and after SC-CO2 treatments

Untreated Treated at 12MPa 40∘C 30min Treated at 12MPa 45∘C 15minAppearance

Product loss 225 plusmn 249a 220 plusmn 257a 210 plusmn 260a

Discoloration 260 plusmn 226a 27 plusmn 195a 230 plusmn 177a

TextureCrispy 683 plusmn 201a 733 plusmn 150a 700 plusmn 173a

Hard 695 plusmn 244a 660 plusmn 222a 680 plusmn 187a

Firmness 730 plusmn 208a 740 plusmn 107a 720 plusmn 132a

Fracturability 375 plusmn 277a 430 plusmn 279a 400 plusmn 271a

Grainy 175 plusmn 249a 180 plusmn 253a 170 plusmn 221a

Fibrous 540 plusmn 345a 530 plusmn 356a 520 plusmn 336a

Moistness 335 plusmn 270a 460 plusmn 196a 380 plusmn 244a

TasteCoconut like 645 plusmn 228a 700 plusmn 221a 610 plusmn 218a

Harmonious 680 plusmn 275a 670 plusmn 298a 610 plusmn 251a

Sweet 510 plusmn 240a 540 plusmn 232a 500 plusmn 232a

Bitter 110 plusmn 031a 150 plusmn 085a 140 plusmn 140a

Off taste 115 plusmn 049a 130 plusmn 067a 140 plusmn 084a

AromaFresh coconut 385 plusmn 211a 510 plusmn 233a 440 plusmn 250a

Nutty 165 plusmn 173a 190 plusmn 191a 220 plusmn 220a

Rancid 165 plusmn 201a 160 plusmn 126a 120 plusmn 063a

Off odor 185 plusmn 176a 180 plusmn 148a 160 plusmn 135a

Data are mean values plusmn standard deviations Values with similar letters within rows are not significantly different (119875 gt 005)

the panelists of these compounds A study published by Jiet al [13] also demonstrated that the color modifications ofshrimps induced by SC-CO

2treatment positively influenced

panelistrsquos decision who attributed higher grade scores totreated shrimps compared to the untreated

Overall the results presented in this study clearlydemonstrated that SC-CO

2treatments did not influence

the organoleptic attributes of the product highlighting theacceptability of the product by the consumers

4 Conclusions

Thepresent work provided scientific data on the effects of SC-CO2on the quality aspects of fresh-cut coconut Both SC-

CO2process conditions (12MPa 40∘C 30min and 12MPa

45∘C 15min) influenced product attributes color slightlychanged and fat content TPC pH and antioxidant capacitydecreased while DM and TA increased As regards enzymaticactivity the results showed that POD activity increased andPPO activity was reduced Although complete inactivationwas not achieved the product was not prone to enzymaticoff-flavors and off-colors Sensorial analyses showed thatpanelists could not detect any significant differences interms of texture taste appearance and aroma howevercolor instrumental analyses reported significant differencesin lightness between the untreated and treated samples Inconclusion the results of this work together with the findingsof microbial inactivation previously published [14] highlight

the potentials of SC-CO2pasteurization of solid ready-to-eat

products with firm structure Nevertheless further studiesare needed to investigate the application of the technology onother products looking at microbiological as well as nutri-tional aspects Additionally in view of a possible exploitationat industrial level both an economic feasibility and designand scale-up studies are needed to develop a continuous plantto integrate in the existing process lines

Acknowledgments

The research leading to these results received funding fromthe European Communityrsquos Seventh Framework Program(FP72007ndash2013) under Grant Agreement no 245280 alsoknown with the acronym PRESERF ldquoProcessing Raw Mate-rials into Excellent and Sustainable End products whileRemaining FreshrdquoThe authors are grateful to Sara Balzan forher help in carrying out the experimental runs

References

[1] X Bi JWu Y Zhang Z Xu andX Liao ldquoHigh pressure carbondioxide treatment for fresh-cut carrot slicesrdquo Innovative FoodScience and Emerging Technologies vol 12 no 3 pp 298ndash3042011

[2] M Sinigaglia M R Corbo D DrsquoAmato D Campanielloand C Altieri ldquoShelf-life modelling of ready-to-eat coconutrdquoInternational Journal of Food Science and Technology vol 38 no5 pp 547ndash552 2003


[3] T Ohlsson ldquoMinimal processing-preservation methods of thefuture an overviewrdquoTrends in Food Science and Technology vol5 no 11 pp 341ndash344 1994

[4] B J Jennylynd and N Tipvanna ldquoProcessing of fresh-cuttropical fruits and vegetables a technical guiderdquo in Rap Pub-lication R S Rolle Ed vol 16 pp 1ndash84 Food and AgricultureOrganization of theUnitedNations RegionalOffice forAsia andthe Pacific Bangkok Thailand 2001

[5] Y Tatsumi A E Watada and P P Ling ldquoSodium chloridetreatment orwaterjet slicing effects onwhite tissue developmentof carrot sticksrdquo Journal of Food Science vol 58 pp 1390ndash13921993

[6] L R Howard L E Griffin and Y Lee ldquoSteam treatment ofmin-imally processed carrot sticks to control surface discolorationrdquoJournal of Food Science vol 59 pp 356ndash358 1994

[7] H R Bolin ldquoRetardation of surface lignification on fresh peeledcarrotsrdquo Journal of Food Processing and Preservation vol 16 pp99ndash104 1992

[8] A Amanatidou R A Slump L G M Gorris and E J SmidldquoHigh oxygen and high carbon dioxide modified atmospheresfor shelf-life extension of minimally processed carrotsrdquo Journalof Food Science vol 65 no 1 pp 61ndash66 2000

[9] S Damar and M O Balaban ldquoReview of dense phase CO2

technology microbial and enzyme inactivation and effects onfood qualityrdquo Journal of Food Science vol 71 no 1 pp R1ndashR112006

[10] G Ferrentino and S Spilimbergo ldquoHigh pressure carbondioxide pasteurization of solid foods current knowledge andfuture outlooksrdquo Trends in Food Science and Technology vol 22no 8 pp 427ndash441 2011

[11] C I Wei M O Balaban S Y Fernando and A J PeplowldquoBacterial effect of high pressureCO

2treatment on foods spiked

with Listeria or Salmonellardquo Journal of Food Protection vol 54pp 189ndash193 1991

[12] M T Valverde F Marın-Iniesta and L Calvo ldquoInactivation ofSaccharomyces cerevisiae in conference pear with high pressurecarbon dioxide and effects on pear qualityrdquo Journal of FoodEngineering vol 98 no 4 pp 421ndash428 2010

[13] H Ji L Zhang S Liu X Qu C Zhang and J Gao ldquoOptimiza-tion of microbial inactivation of shrimp by dense phase carbondioxiderdquo International Journal of FoodMicrobiology vol 156 no1 pp 44ndash49 2012

[14] G Ferrentino S Balzan A Dorigato A Pegoretti and SSpilimbergo ldquoEffect of supercritical carbon dioxidepasteuriza-tion on natural microbiota texture andmicrostructure of fresh-cut coconutrdquo Journal of Food Science vol 77 no 5 pp E137ndashE143 2012

[15] R Hunter and R W Harold The Measurement of Appearancechapter 11 JohnWiley amp Sons NewYork NY USA 2nd edition1975

[16] G Ferrentino S Balzan and S Spilimbergo ldquoOn-line colormonitoring of solid foods during supercritical CO

2pasteuriza-

tionrdquo Journal of Food Engineering vol 110 no 1 pp 80ndash85 2012[17] Association of Official Analytical Chemists (AOAC) Official

Methods of Analysis AOAC International Baltimore Md USA16th edition 1995

[18] ISO 659 ldquoDetermination of oil contentrdquo (Reference method)1998

[19] J Lachman VHosnedl V Pivec andMOrsak ldquoPolyphenols incereals and their positive andnegative role in human and animalnutritionrdquo in Proceedings of Conference Cereals for HumanHealth and Preventive Nutrition pp 118ndash125 1998

[20] T E Kramling and V E Singleton ldquoAn estimate of thenonflavonoid phenols in winesrdquo American Journal of Enologyamp Viticulture vol 20 pp 86ndash92 1969

[21] IOOC ldquoDetermination of biophenols in olive oils by HPLCrdquo2008 httpwwwinternationaloliveoilorgwebaa-inglescorpAreasActivitieeconomicsAreas Activitiehtml

[22] W Brand-Williams M E Cuvelier and C Berset ldquoUse of a freeradical method to evaluate antioxidant activityrdquo Lebensmittel-Wissenschaft und-Technologie vol 28 no 1 pp 25ndash30 1995

[23] R Re N Pellegrini A Proteggente A PannalaM Yang andCRice-Evans ldquoAntioxidant activity applying an improved ABTSradical cation decolorization assayrdquo Free Radical Biology andMedicine vol 26 no 9-10 pp 1231ndash1237 1999

[24] P Arnnok C Ruangviriyachai R Mahachai S Techa-wongstien and S Chanthai ldquoOptimization and determinationof polyphenol oxidase and peroxidase activities in hot pepper(Capsicum annuum L) pericarbrdquo International Food ResearchJournal vol 17 no 2 pp 385ndash392 2010

[25] R C Soliva P Elez M Sebastian and O Martın ldquoEvaluationof browning effect on avocado puree preserved by combinedmethodsrdquo Innovative Food Science and Emerging Technologiesvol 1 no 4 pp 261ndash268 2000

[26] J Dıaz A Bernal F Pomar and F Merino ldquoInduction ofshikimate dehydrogenase and peroxidase in pepper (Capsicumannuum L) seedlings in response to copper stress and itsrelation to lignificationrdquo Plant Science vol 161 no 1 pp 179ndash188 2001

[27] D Komes A Belscak-Cvitanovic D Horzic H Drmic SSkrabal and B Milicevic ldquoBioactive and sensory propertiesof herbal spirit enriched with cocoa (Theobroma cacao L)polyphenolicsrdquo Food Bioprocess Technology vol 5 no 7 pp2908ndash2920 2012

[28] T Koksal and I Dikbas ldquoColor stability of different dentureteeth materials against various staining agentsrdquo Dental Materi-als Journal vol 27 no 1 pp 139ndash144 2008

[29] D Kincal W S Hill M Balaban et al ldquoA continuous high-pressure carbon dioxide system for cloud and quality retentionin orange juicerdquo Journal of Food Science vol 71 no 6 pp C338ndashC344 2006

[30] G Ferrentino M L Plaza M Ramirez-Rodrigues G Ferrariand M O Balaban ldquoEffects of dense phase carbon dioxidepasteurization on the physical and quality attributes of a redgrapefruit juicerdquo Journal of Food Science vol 74 no 6 pp E333ndashE341 2009

[31] D D Pozo-Insfran M O Balaban and S T Talcott ldquoMicrobialstability phytochemical retention and organoleptic attributesof dense phase CO

2processed muscadine grape juicerdquo Journal

of Agricultural and Food Chemistry vol 54 no 15 pp 5468ndash5473 2006

[32] X Liu YGaoH XuQHaoG Liu andQWang ldquoInactivationof peroxidase and polyphenol oxidase in red beet (Beta vulgarisL) extract with continuous high pressure carbon dioxiderdquo FoodChemistry vol 119 no 1 pp 108ndash113 2010

[33] G R Bankar P G Nayak P Bansal et al ldquoVasorelaxant andantihypertensive effect of Cocos nucifera Linn endocarp onisolated rat thoracic aorta andDOCAsalt-induced hypertensiveratsrdquo Journal of Ethnopharmacology vol 134 no 1 pp 50ndash542011

[34] A Escarpa and M C Gonzalez ldquoAn overview of analyticalchemistry of phenolic compounds in foodsrdquo Critical Reviews inAnalytical Chemistry vol 31 no 2 pp 57ndash139 2001


[35] J A Vinson X Su L Zubik and P Bose ldquoPhenol antioxidantquantity and quality in foods fruitsrdquo Journal of Agricultural andFood Chemistry vol 49 no 11 pp 5315ndash5321 2001

[36] S-J Park J-I Lee and J Park ldquoEffects of a combined process ofhigh-pressure carbon dioxide and high hydrostatic pressure onthe quality of carrot juicerdquo Journal of Food Science vol 67 no 5pp 1827ndash1834 2002

[37] D D Pozo-Insfran M O Balaban and S T Talcott ldquoInactiva-tion of polyphenol oxidase in muscadine grape juice by densephase-CO

2processingrdquo Food Research International vol 40 no

7 pp 894ndash899 2007[38] F S Burnette ldquoPeroxidase and its relationship to food flavour

and quality A reviewrdquo Journal of Food Science vol 42 pp 1ndash61977

[39] E M Goncalves J Pinheiro M Abreu T R S Brandaoand C L M Silva ldquoCarrot (Daucus carota L) peroxidaseinactivation phenolic content and physical changes kineticsdue to blanchingrdquo Journal of Food Engineering vol 97 no 4pp 574ndash581 2010

[40] A T Fricks D P B Souza E G Oestreicher et al ldquoEvaluationof radish (Raphanus sativus L) peroxidase activity after high-pressure treatment with carbon dioxiderdquo The Journal of Super-critical Fluids vol 38 no 3 pp 347ndash353 2006

[41] M S Primo G C Ceni N S Marcon et al ldquoEffects ofcompressed carbon dioxide treatment on the specificity ofoxidase enzymatic complexes frommate tea leavesrdquoThe Journalof Supercritical Fluids vol 43 no 2 pp 283ndash290 2007

[42] F Gui F Chen JWu ZWang X Liao andXHu ldquoInactivationand structural change of horseradish peroxidase treated withsupercritical carbon dioxiderdquo Food Chemistry vol 97 no 3 pp480ndash489 2006

[43] M Habulin and Z Knez ldquoActivity and stability of lipasesfrom different sources in supercritical carbon dioxide andnear-critical propanerdquo Journal of Chemical Technology andBiotechnology vol 76 no 12 pp 1260ndash1266 2001

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


appearance could not be a restraint but an improvement inthe development of an innovative pasteurization techniquedepending on people and cultural habits

As concerns fresh-cut coconut one study has beenrecently published to assess the effectiveness of SC-CO

2as

nonthermal technique for the pasteurization of such a prod-uct assuring its microbial safety The results clearly demon-strated the potential of SC-CO

2pasteurization of fresh-

cut coconut which significantly reduced total mesophilicmicroorganisms total coliforms yeasts andmolds and lacticacid bacteria naturally present on its surface The optimalprocess conditions identified were 12MPa 40∘C 30min and12MPa 45∘C 15min at which 4 Log(CFUg) reductions wereachieved for the mentioned microbial strains [14]

At this stage the investigation of the impact of suchtechnology on the quality attributes of the product is neededin view of a possible development of SC-CO

2process at

industrial scale In this concern the aim of the present studyis the evaluation of the effects of SC-CO

2process on the

quality attributes of fresh-cut coconut in terms of colorpH titratable acidity (TA) fat content dry matter (DM)indigenous enzyme activity total phenol content (TPC)flavonoid compounds (FC) antioxidant capacity and sensoryattributes (aroma taste appearance and texture)

2 Materials and Methods

21 Sample Preparation Coconut (Cocos nucifera) was pur-chased from a local market deshelled cleaned washedwith water and manually cut in pieces The samples weretransferred into the reactor and treated at 12MPa 40∘C for30min and 12MPa 45∘C for 15min The process conditionswere chosen on the basis of the previous study on microbialinactivation [14] they assured the highest pasteurizing effect(47 log reductions of mesophilic microorganisms 26 logreductions of lactic bacteria 46 log reductions of totalcoliforms and 32 log reductions of yeasts and molds) on thenatural microbial flora occurred on fresh-cut coconut

22 High Pressure Carbon Dioxide Equipment SC-CO2

treatment was performed in the batch apparatus shownin Figure 1 Liquid CO

2(99990 purity Messer Group

GmbH Germany) was fed into a high pressure vessel by avolumetric pump (LCD1M910s LEWA GmbH Germany)with a maximum flow rate of 11 lh The vessel consistedof a 310mL stainless steel cylinder (height 110mm innerdiameter 60mm) and was equipped with a resistance tem-perature probe (Pt 1001015840Ω Endress+Hauser Milano Italy)and a pressure gauge (Gefran Brescia Italy) The sample wasloaded into the vessel heated to a defined temperature andsubsequently pressurized with CO

2 The system was kept at

the process conditions of temperature and pressure for thetime required for the treatment and then slowly depressur-ized Pressure and temperature were continuously recorded

by a real time data acquisition system (field point FP-1000RS 232RS 485 NATIONAL INSTRUMENTS Austin TexasUSA) and monitored by a specific software (LabVIEW 50)Thedepressurization stepwas performedby partially openingtwo micrometric valves (2S-4L-N-SS Rotarex Brescia Italy)placed on the output line of the system heated with anelectrical resistance (80W CSC2 Backer Fer Ferrara Italy)to prevent CO

2freezing during the expansion to ambient

pressure After each experimental run the reactor waswashed with water and sterilized in autoclave (121∘C 15min)to prevent possible contaminations while CO

2was flushed at

6 MPa through all tubes to ensure a good level of cleaning

23 Color Measurements Color parameters were measuredwith a high resolution miniature spectrometer (HR2000+Ocean Optics Inc Dunedin FL) to which a fiber opticreflection probe (QR600-7-UV-125BX Ocean Optics IncDunedin FL) was connectedThe probe transmitted the lightfrom a halogen lamp to the sample surface by the illuminatingfibers while the reflected light from the sample was acquiredby a reading fiber and measured by the spectrometer Aftercalibration the samplewas placed on a holding device and thesignal acquired by a specific software (Spectra Suite OceanOptics Dunedin FL USA) which provides Llowast(lightness)alowast(redness) and blowast(yellowness) parameters Color analyseswere performed on samples treated three times at the sameprocess conditions and the mean values together with thestandard deviations reported Additionally in order to quan-tify the overall color differences Δ119864 values were evaluatedbased on the following equation [15]

Δ119864 = radic(119871lowast

1minus 119871lowast

2)2

+ (119886lowast

1minus 119886lowast

2)2

+ (119887lowast

1minus 119887lowast

2)2

(1)

where Llowast alowast and 119887lowast with subscript numbers representlightness redness and yellowness measured before and aftertreatments respectively More details of the procedure can befound elsewhere [16]

24 pH Determination The sample (30 grams) was homoge-nized with 30mL of distilled water and the pH was measuredusing a digital pH meter (Eutech Instruments NijkerkThe Netherlands) after calibration with commercial buffersolutions at pH 70 and 40 The measurements in triplicatefor each condition were performed recording the pH of10mL of the homogenized solutions

25 Titratable Acidity Measurements 10mL of a solutionobtained from the sample (30 grams) homogenized with30mL of distilled water was titrated against standardizedNaOH (005N) to the phenolphthalein end point (pH = 82plusmn01) The volume of NaOH was converted to grams of lauricacid (considered the prevalent acid in fresh-cut coconut) permL of the homogenized solution and titratable acidity (TA)calculated based on the following formula

TA (lauric acid gL) =(mL NaOH used) sdot (Normality of NaOH) sdot (Molecular weight of lauric acid)

mL homogenized sample (2)


Data acquisition

PTT

Thermostatic bath

Vessel

Filter

Pump

PI

PI

V4V3R2

V1 Heatexchanger

R1V2

CO2 tank


pressure manometer

















2O2



sdotΔ119860

Δ119905 (3)



Untreated

Col

or p

aram

eter

s

minus2

0

2

4

70

80

90

100

aaaa a

ba

a

b

Treated at 12 MPa45


∘C 30 min
















(mg GAEgDM)

ABTS(120583mol

Troloxg DM)

DPPH(120583mol








2[29 30]











2treatments respec-


2treatment


2at 345MPa 30∘C








2treatments









minus3a










2processing




2treatment on









































4 Conclusions






Acknowledgments


References





















2pasteuriza-











































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


Data acquisition

PTT

Thermostatic bath

Vessel

Filter

Pump

PI

PI

V4V3R2

V1 Heatexchanger

R1V2

CO2 tank


pressure manometer

















2O2



sdotΔ119860

Δ119905 (3)



Untreated

Col

or p

aram

eter

s

minus2

0

2

4

70

80

90

100

aaaa a

ba

a

b

Treated at 12 MPa45


∘C 30 min
















(mg GAEgDM)

ABTS(120583mol

Troloxg DM)

DPPH(120583mol








2[29 30]











2treatments respec-


2treatment


2at 345MPa 30∘C








2treatments









minus3a










2processing




2treatment on









































4 Conclusions






Acknowledgments


References





















2pasteuriza-











































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of







2O2



sdotΔ119860

Δ119905 (3)



Untreated

Col

or p

aram

eter

s

minus2

0

2

4

70

80

90

100

aaaa a

ba

a

b

Treated at 12 MPa45


∘C 30 min
















(mg GAEgDM)

ABTS(120583mol

Troloxg DM)

DPPH(120583mol








2[29 30]











2treatments respec-


2treatment


2at 345MPa 30∘C








2treatments









minus3a










2processing




2treatment on









































4 Conclusions






Acknowledgments


References





















2pasteuriza-











































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of





(mg GAEgDM)

ABTS(120583mol

Troloxg DM)

DPPH(120583mol








2[29 30]











2treatments respec-


2treatment


2at 345MPa 30∘C








2treatments









minus3a










2processing




2treatment on









































4 Conclusions






Acknowledgments


References





















2pasteuriza-











































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of








minus3a










2processing




2treatment on









































4 Conclusions






Acknowledgments


References





















2pasteuriza-











































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of





























4 Conclusions






Acknowledgments


References





















2pasteuriza-











































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



















2pasteuriza-











































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

research article quality attributes of fresh-cut coconut after supercritical carbon...

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