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Sorrel (Rumex acetosa L.) is a perennial wild herb appreciated as a folk medicine and for use in folk-traditional cuisines, and its nutraceutical properties are increasingly known and studied. Nowadays, there is a lack of knowledge about the possibility of using this species as fresh-cut produce, and no reports have investigated the physiological/biochemical changes of sorrel leaves upon storage. To test the aforementioned, sorrel seedlings were cultivated in a floating system and two consecutive harvests took place: the first cut at 15 days (C1) and second cut at 30 days (C2) after sowing. Fresh-cut sorrel leaves from C1 and C2 were stored in plastic boxes at 4 °C for 15 days and chlorophylls, carotenoids, total phenols, flavonoids, ascorbic acid, and antioxidant capacity were evaluated during the storage period. During storage, sorrel leaves from the same cut did not show significant changes in total phenolic content and antioxidant capacity, which represents a positive outcome for the maintenance of the nutraceutical value of this species. For this reason, sorrel may be a very promising species as a "new" fresh-cut leafy vegetable. However, some differences were observed between the two cuts, especially in the total flavonoid and the total ascorbic acid contents. While promising, further research will be necessary to standardize the yield and the nutraceutical content of this species in different cuts, which will be necessary to introduce and promote sorrel to consumers.
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Horticulturae2020,6,4;doi:10.3390/horticulturae6010004www.mdpi.com/journal/horticulturae
Article
SuitabilityofHydroponicallyGrownRumexacetosa
L.asFreshCutProduce
CostanzaCeccanti
1
,MarcoLandi
1,2,
*,LucaIncrocci
1
,AlbertoPardossi
1,2
andLuciaGuidi
1,2
1
DepartmentofAgriculture,FoodandEnvironment,UniversityofPisa,56124Pisa,Italy;
c.ceccanti3@studenti.unipi.it(C.C.);luca.incrocci@unipi.it(L.I.);alberto.pardossi@unipi.it(A.P.);
lucia.guidi@unipi.it(L.G.)
2
InterdepartmentalResearchCenterNutrafood“NutraceuticalsandFoodforHealth”,UniversityofPisa,
56124Pisa,Italy
*Correspondence:marco.landi@unipi.it
Received:29November2019;Accepted:2January2020;Published:9January2020
Abstract:Sorrel(RumexacetosaL.)isaperennialwildherbappreciatedasafolkmedicineandfor
useinfolktraditionalcuisines,anditsnutraceuticalpropertiesareincreasinglyknownandstudied.
Nowadays,thereisalackofknowledgeaboutthepossibilityofusingthisspeciesasfreshcut
produce,andnoreportshaveinvestigatedthephysiological/biochemicalchangesofsorrelleaves
uponstorage.Totesttheaforementioned,sorrelseedlingswerecultivatedinafloatingsystemand
twoconsecutiveharveststookplace:thefirstcutat15days(C1)andsecondcutat30days(C2)after
sowing.FreshcutsorrelleavesfromC1andC2werestoredinplasticboxesat4°Cfor15daysand
chlorophylls,carotenoids,totalphenols,flavonoids,ascorbicacid,andantioxidantcapacitywere
evaluatedduringthestorageperiod.Duringstorage,sorrelleavesfromthesamecutdidnotshow
significantchangesintotalphenoliccontentandantioxidantcapacity,whichrepresentsapositive
outcomeforthemaintenanceofthenutraceuticalvalueofthisspecies.Forthisreason,sorrelmay
beaverypromisingspeciesasa“new”freshcutleafyvegetable.However,somedifferenceswere
observedbetweenthetwocuts,especiallyinthetotalflavonoidandthetotalascorbicacidcontents.
Whilepromising,furtherresearchwillbenecessarytostandardizetheyieldandthenutraceutical
contentofthisspeciesindifferentcuts,whichwillbenecessarytointroduceandpromotesorrelto
consumers.
Keywords:sorrel;coldstorage;wildherb;postharvest;bioactivecompounds;hydroponicsystem;
shelflife
1.Introduction
Sorrel(RumexacetosaL.)isaperennialwildedibleherb,belongingtothePolygonaceaefamily,
knownfromancienttimesthroughouttheMediterraneanregion.Itisappreciatedasafolkmedicine
foritsmedicinalproperties[1–4].Indeed,somestudieshavereportedthatsorrelplantsshowed
medicinalpropertiesforthetreatmentofcutaneousdiseases,jaundice,sorethroat,wartsand,
especiallysorrelleavesshowedpropertiesforthetreatmentoffever,diarrhea,lackofappetite,
worms,andasa“bloodcleanser”[1,2].Sorrelleafextractshavealsoshownantimutagenic,cytotoxic,
andantiproliferativeactivitiesagainsthumancancercells[3,4].Inthepast,timesoffamineorfood
scarcityturnedpeople’sinteresttowildherbsasfood,butnowtheuseofwildedibleproductsis
becomingpopularinourmodernsociety[5].Sorrelisalsoappreciatedforuseinfolktraditional
cuisinessuchasboiledvegetables,pies,andmixedsalads[3].Numerousstudieshavereportedthe
presenceofphytochemicalsinsorrelaerialparts(sinapicacid,vanillicacid,6methyl1,3,8
trichlorodibenzofuran,chrysophanol,physcion/parietin,emodin8O
D
glucopiranoside,
naphthalene1,8diol,catechin/epicatechin,epicatechin3Ogallate,vitexine,pulmatin,
Horticulturae2020,6,42of9
gallocatechin/epigallocatechin,procyanidinB2,geraniin,corilagin,ellagicacid,rosmarinicacid,and
pyrogallol[1,4–7]).
Thedemandforahighervarietyofvegetablespeciesinthedietcanbesatisfiedbyevaluating
thesuitabilityofnewediblespecies,includingsorrel,forcultivationasa“new”leafyvegetable.In
fact,theintroductionofcultivationofthisspeciesand,consequently,intothemarketwouldleadto
thediversificationofvegetablecropsandthewideningofthesuppliesofleafyvegetables.
Thedevelopingdemandforvegetablecropsencouragestheintroductionofthisspeciesintothe
freshcutproductsmarket.Freshcutproductsareobtainedfromminimallyprocessedleafy
vegetablesorfruitswhicharepackagedinfilmorplasticboxes,stored,transported,andsoldat
temperaturesbetween0to8°C(usually4–5°C),accordingtoItalianRegulationnumber77/2011and
ItalianMinisterialDecreenumber3746/2014[8].Theshelflifediffersamongdifferentfreshcut
productsdueinparttocropspecificenzymaticbrowningwhichusuallydevelopsduringcold
storage[9].Infact,enzymaticbrowningofacutsurfaceisaproblemfornumerousleafyfreshcut
productssuchaslettuce(Lactucasativa)orcabbage(Brassicaoleracea)[9–11].Thebrowningresults
fromtheoxidationofphenolstoquinones,whichiscatalysedbypolyphenoloxidaseandinfluenced
bytemperature,pH,andoxygenavailabilityinthetissues[12].Theshelflifeofmostfreshcut
productshasbeenestablishedintherangeof7–15days[13].Currently,littleinformationisavailable
ontheuseofnewedibleherbs,suchassorrel,whencultivatedinhydroponicsystemsandontheir
shelflifeasfreshcutproducts.Infact,hydroponiccultivation,especiallyafloatingsystem,isan
efficientcultivationtechniquewhichallowsmodulationofthenutrientsolutionbasedontheunique
needsofeachhorticulturalspecies[14,15].Moreover,harvestbycuttingandallowingregrowthof
plantsisacurrentlyusedpracticeforleafyhorticulturalcropswhichwillbeprocessedasfreshcut
products(e.g.,lettuce[16]).
Therefore,theaimofthisworkwastodeterminethequalityofhydroponicallycultivatedsorrel
leavesfromtwoconsecutiveharvests.Foreachharvest,themainnutraceuticalcompoundswhere
measuredduring15daysofcoldstorage.Theresultswilllayafoundationfortheintroductionofa
“new”nutraceuticallyvaluableleafyspeciesinmarketswiththegoaltoenrichtheMediterranean
diet.
2.MaterialsandMethods
2.1.MaterialPreparationandExperimentalSetup
TheworkwascarriedoutinagreenhouseoftheDepartmentofAgriculture,Foodand
Environment(UniversityofPisa,Pisa,Italy)fromJunetoJuly2018.Seedsofsorrelwerepurchased
fromS.A.I.S.S.p.a.(SocieAgricolaItalianaSementi,Cesena,Italy)andtheyweresownin
polystyrenetrays(120holes)forgermination.Sproutsweregrowningreenhouseuntiltheyhad4or
5trueleavesandwerereadyfortransplanting.Thetransplantingwascarriedoutinthegreenhouse
in16holepolystyrenetrayswhichwereplacedintankswith50Lofnutritivesolution,typicalof
floatingsystemcultivation,composedof:10mMNO3,0.5mMNH4+,1mMPO43,6mMK+,4mM
Ca2+,2mMMg2+,0.5mMNa+,3.5mMSO42,0.5mMCl,0.5mMHCO3,40μMFe2+,25μMBO3,1
μMCu2+,5μMZn2+,10μMMn2+,and1μMMo3+.Thegrowingsolutionwaspreviouslyoptimized
forsorrelcultivationbyCeccantietal.[7].Electricalconductivitywas1.98dSm1;pHwasadjusted
to5.7–6.0withdilutesulphuricacid.Thenutrientsolutionwascontinuouslyaerated.At15daysafter
transplanting,whenseedlingshad15–20leaves,plantswereharvestedbycuttingtheentireaerial
partoftheplantatthebase(C1).At15daysafterC1,whenseedlingshadregrownandhad15–20
leaves,plantswereagainharvestedbyasecondcutoftheentireaerialpartoftheplantatthebase
(C2).Duringthepostharvest,leavesobtainedfromC1andfromC2weretransportedtothe
laboratory.Apartofthefreshmaterialfromeachplantwasfrozenusingliquidnitrogenandstored
at−80°Cforbiochemicalanalyses.Anotherpartofthefreshmaterialwasimmediatelystoredand
packedasafreshcutproduct.Samplesof15goffreshsorrelleaveswerepackedinpolyethylene
terephthalate(PET)boxes(150cm3,ComitalCofresco,Volpiano(TO),Italy)andstoredfor15dat4
°Cinthedark.Analysestodeterminetotalphenol,flavonoid,chlorophyll,carotenoid,andascorbic
Horticulturae2020,6,43of9
acidcontentaswellasthetotalantioxidantcapacitywereperformedusingthefreshmaterial(t0)and
at1,2,3,6,9,13,and15dofcoldstorage.
2.2.TotalPhenolicandTotalFlavonoidContents
Leafsamples(1g)werehomogenisedin4mL80%(v/v)methanolsolution,thenweresonicated
usingasonicator(DigitalultrasonicCleaner,DU45,ArgoLab,Modena,Italy)for30minand
centrifuged(MPW260R,MWPMed.instruments,Warsaw,Poland)at10,000×gfor15minat4°C.
Thesupernatants(2mL)werethencentrifugedfor3minat7000×g.Extractswereusedforthe
analysisofthetotalphenolandflavonoidcontentandtheantioxidantcapacityassay.
TotalphenoldeterminationwasperformedusingthemethodofDewantoetal.[17]withsome
modifications.Extractedsamples(10μL)wereaddedtoasolutionof115μLdeionizedwaterand125
μLFolinCiocalteaureagent.Blanksolutionswereperformedwith10μLdistilledwater,insteadof
theextract.Sampleswerestirredand,after6min,1.25mL7%(w/v)Na2CO3wereadded.Samples
wereincubatedfor90minatroomtemperatureandtheincreaseinabsorbanceat760nmusingan
Ultrospec2100Prospectrophotometer(GEHealthcareLtd.,LittleChalfont,UK)wasmeasured
againstablanksolution.Usingagallicacidstandardcurve,theresultswereexpressedasmggallic
acidequivalentspergFW(mgGAEg1FW).
FlavonoiddeterminationwasperformedusingthemethodofDuetal.[18]withsome
modifications.Analiquotofsampleextract(100μL)wasaddedtoasolutionof440μLdeionized
waterand30μLNaNO25%(w/v).Sampleswerestirredandthenheldfor6min.Then,30μL10%
(w/v)AlCl3wereaddedtosampleswhichwerestirredagain.After6min,400μLNaOH4%(w/v)
wereaddedtosamplesandthemixturewasstirredandincubatedfor15minatroomtemperature.
Theincreaseinabsorbanceat510nmwasmeasuredspectrophotometricallyagainstablanksolution
madewithdistilledwater.Usingacatechinstandardcurve,theresultswereexpressedasmgcatechin
equivalentspergFW(mgCAEg–1FW).
2.3.TotalChlorophyllandTotalCarotenoidContents
Chlorophyllandcarotenoidcontentsweredeterminedusingthespectrophotometricmethod
describedbyPorraetal.[19]withsomemodifications.Analiquotof0.3goffreshmaterialwas
extractedwith20mL80%(v/v)acetoneandstirredfor72hat4°Cinthedark.
Spectrophotometrically,theincreaseinabsorbanceat663,648,and470nmweredetectedtocalculate
chlorophylla,chlorophyllb,andcarotenoidcontentagainstablanksolution(onlymadeby80%(v/v)
aqueousacetone).TheresultswereexpressedasmgchlorophyllorcarotenoidpergFW(mgCHLor
CARg–1FW).
2.4.TotalAscorbicAcidContent
Ascorbicacidcontentwasmeasuredspectrophotometricallyusingthemethoddescribedby
Kampfenkeletal.[20]withsomemodifications.Extractionswerecarriedoutwiththe
homogenizationof0.3gfreshmaterialwith1mL6%(v/v)trichloroaceticacidfollowedby
centrifugingfor10minat10,000×gat4°C.Immediately,theanalysiswasperformedbyadding50
μLsupernatantto50μL10mMdithiothreitol(DTT)andto100μL0.2MNaPbuffer(pH7.4).
Sampleswerestirredandincubatedfor15minat42°Cinawaterbath.Then,50μL0.5%(w/v)N
ethylmaleimide(NEM)wereaddedandsampleswerestirredagain.After1minofstirring,250μL
10%(v/v)trichloroacetic,200μL42%(w/v)orthophosphoricacid,200μL4%(w/v)2,2dipyridil
(dilutedin70%(v/v)ethanol70%(v/v)),and100μL3%(w/v)FeCl3wereaddedtosamples.The
increaseinabsorbanceat525nmwasmeasuredagainstblanksolution(with6%(v/v)trichloroacetic
acid,insteadofsupernatant)after40minofincubationat42°Cinawaterbath.Usinganascorbic
acidstandardcurve,theresultswereexpressedasmgascorbicacidpergFW(mgASAg–1FW).
Horticulturae2020,6,44of9
2.5.AntioxidantCapacityAssay
Theantioxidantcapacitywasmeasuredspectrophotometricallybyusingthe2,2diphenyl1
picrylhydrazylhydrate(DPPH)freeradicalscavengingassay[21].Thesameextractusedforphenol
andflavonoiddeterminationwasused.Theincreaseinabsorbancewasmeasuredat515nmafter30
minofincubationof10μLextractaddedto900μLDPPHsolution(0.024gin200mL80%(v/v)
methanol).UsingaTrolox(6hydroxy2,5,7,8tetramethylchroman2carboxylicacid)standardcurve,
theresultswereexpressedasmgTroloxequivalentspergFW(mgTroloxg
–1
FW).
2.6.StatisticalAnalyses
Todeterminetheeffectofthetwoconsecutivecutsandofthestoragetime,atwowayANOVA
wasperformedusingGraphPad(GraphPad,LaJolla,CA,USA)asthestatisticalsoftware.Mean
values±standarddeviation(SD)of3replicatesforeachassaywerecomparedbytheleastsignificant
differencestestatp=0.05toidentifysignificantdifferencesamongtreatmentsandsignificant
interactionsbetweenfactors.
3.ResultsandDiscussion
ThetotalphenoliccontentwassignificantlylowerinleavesofR.acetosaderivedfromC2than
thosefromC1,andthisdifferenceremainedconstantduringstorage(Figure1a).Thismaysuggest
thatcarbondedicatedtothebiosynthesisofsecondarymetabolites(suchasphenols)wasdevotedto
structuralpolymersofnewcellsduringtheregrowthoftheplantsafterC1insteadoftosecondary
metabolites.Othershavereportedthattheeffectofafirstharvestresultedinhigherphotosynthetic
rateandplantyieldbutdidnotinduceenhancementofsecondarymetabolitecontent[16].However,
onlyafewstudieshavereportedontheharvesteffectonsecondarymetaboliteprofileofleafy
vegetables,andthisaspectrequiresfurtherinvestigation.Duringcoldstorage,totalphenoliccontent
inleavesobtainedfromC1andfromC2remainedconstant,exceptforaslightincreaseafter9days
inleavesderivedfromC1.Thislastaspectisalsoevidentintheflavonoidpattern,whereamoderate
increaseafter9daysofcoldstorageoccurred(Figure1b).
(a)(b)
Figure1.Totalphenoliccontent(a)andflavonoidcontent(b)ofRumexacetosastoredat4°Cfor15
daysasfreshcutproducts.Closedandopensymbolsrepresentfirst(C1)andsecondharvests(C2),
respectively.Eachvalueisthemean(±SD)ofthreereplicates.Meanshavingthesameletterarenot
significantlydifferentatp=0.05followingtwowayANOVAwithstorage(S)andcut(C)asvariables.
Fvaluesformaineffectsandtheirinteractionsignificantatp<0.05(*);p<0.01(**);p<0.001(***),or
notsignificant(ns).Totalphenolcontentvaluesandflavonoidcontentvalueswereexpressedasgallic
acidequivalents(GAE)mgg
–1
FWandascatechinequivalents(CAE)mgg
–1
FW,respectively.
However,similartototalphenoliccontent,totalflavonoidcontentofleavesobtainedfromC2
hadalowercontentthanleavesobtainedfromC1.TheflavonoidcontentinleavesfromC2wasmore
stablethanthatofleavesobtainedfromC1.Thepatternoftotalphenoliccontentduringstorageisin
agreementwithstudiesofotherspeciessuchaslettuce,rocket,andescarole[22–25],eventhoughthe
phenolicamountwaslowerthanthatfoundinsorrel,especiallyinleavesobtainedfromC1.In
Horticulturae2020,6,45of9
contrast,Castaneretal.[26]showedthattheflavonoidcontentinlettucedecreasedduringcold
storagebecauseoftheenzymaticbrowningreaction,activatedatthecutbytheoxidationofphenols
presentinphotosynthetictissues.
Amongpigments,chlorophyllcontentdidnotchangesignificantlyduringstorage,similarlyto
totalphenolandtotalflavonoidcontent,whilstcarotenoidcontentshowedsomeslightbutsignificant
fluctuations(Figure2).
(a)(b)
Figure2.Chlorophyllcontent(a)andcarotenoidcontent(b)ofRumexacetosastoredat4°Cfor15days
asfreshcutproducts.Closedandopensymbolsrepresentfirst(C1)andsecondharvests(C2),
respectively.Eachvalueisthemean(±SD)ofthreereplicates.Meanshavingthesameletterarenot
significantlydifferentatp=0.05followingtwowayANOVAwithstorage(S)andcut(C)asvariables.
Fvaluesformaineffectsandtheirinteractionsignificantatp<0.05(*);p<0.001(***),ornotsignificant
(ns).Chlorophyll(CHL)andcarotenoid(CAR)contentvalueswerebothexpressedasmgg
–1
FW.
Theseresultsarepartiallyinagreementwiththebehaviourofpigmentcontentinfreshcut
rocket(Erucavesicaria)andchicory(Cichoriumintybus)foundbyothers[27].Infact,thetotal
chlorophyllcontentremainedunchangedfromthebeginningofexperimentuntiltheendofthe
storageperiod,whereascarotenoidcontentdecreaseduponstorage,whichisquitesimilartoour
results[27].Ithasbeenshownthatthechangeinchlorophyllcontentisverydifferentifleaveswere
storedunderlightconditions.Theexplanationisthattheactionofchlorophyllasedegrades
chlorophyll.Chlorophyllaseisanenzymewhichispresentintheenvelopemembraneofthe
chloroplastand,therefore,isseparatedfromchlorophyllaswellasisinvolvedinchlorophyll
metabolism[28].Thesynthesisandtheactivityofthisenzymehasbeenassociatedwiththepresence
ofchlorophyllproteincomplexes.Lightconditionsimprovetheformationoflightharvesting
chlorophyllabproteincomplexinsidethethylakoidsofchloroplast.Thismeansthatthisenzyme
doesnotremainincontactwithchlorophylluntilthylakoidmembranesaredegraded.Accordingly,
theactivityofchlorophyllaseshouldbecorrelatedwiththedegradationofmembranes[28].
Similarlytophenolicandflavonoidcontents,ascorbicacidcontentwashigherinsorrelleaves
obtainedfromC1thanthoseobtainedfromC2(Figure3)andaveraged0.45mgg
–1
FWinC1at
harvestand0.37mgg
–1
inC2.
Horticulturae2020,6,46of9
Figure3.AscorbicacidcontentofRumexacetosastoredat4°Cfor15daysasfreshcutproducts.Closed
andopensymbolsrepresentfirst(C1)andsecondcut(C2)duringthegrowth,respectively.Eachvalue
isthemean(±SD)ofthreereplicates.Meanshavingthesameletterarenotsignificantlydifferentatp
=0.05followingtwowayANOVAwithstorage(S)andcut(C)asvariables.Fvaluesformaineffects
andtheirinteractionsignificantatp<0.001(***).Ascorbicacidcontentvalueswereexpressedas
ascorbicacid(ASA)mgg
–1
FW.
InleavesobtainedfromC1,anincreaseinASAcontentwasobservedduringthefirstsixdays
ofcoldstorage;then,ASAcontentdecreasedandremainedunchangeduntiltheendofcoldstorage
whenthecontentwaslowerascomparedtotheharvestdate(Figure3).InleavesobtainedfromC2,
ASAcontentdecreasedduringcoldstorage,decliningby60%attheendofstorageascomparedto
valuesatharvest(Figure3).However,ASAlevelsinthisspecieswereclosetothosefoundinleafy
vegetablesconsideredagoodsourceofvitaminC,likespinach(Spinaciaoleracea)[29–31].Thecontent
ofASAinleavesisrelatedalsototheseasonofcultivationand,inthissense,Phillipsetal.
[30]
reportedthatinspinachtheASAcontentaveraged0.44,0.30,0.18,and0.18mgg
–1
FWwhengrown
inwinter,spring,summer,andfall,respectively.Incontrast,differentresultswerefoundby
Bergquistetal.[29]whoshowedthatspinachleaveshadalowerASAcontentinwinterthanin
summer(0.14against0.46mgg
–1
FW).
AntioxidantcapacityshowedamoreconstantlevelinsorrelleavesobtainedfromC2thanthat
observedinleavesobtainedfromC1,eventhoughvaluesofantioxidantcapacityinleavesfromC2
weresignificantlylowerthanthosefromC1(Figure4).LeavesobtainedfromC1showedasubstantial
decreaseafterninedaysofstoragewhichparalleledthedecreaseinphenols,flavonoid,andASA
contents,whichsuggeststheimportanceofthesemetabolitesinantioxidantcapacity.Notably,sorrel
leavesfromC1andfromC2exhibitedanantioxidantcapacityhigherthanseveralvegetablesasred
cabbage(B.oleracea),carrots(Daucuscarota),onions(Alliumcepa),andbabycoslettuce(L.sativa)
[32,33].
Horticulturae2020,6,47of9
Figure4.TheantioxidantcapacityofRumexacetosastoredat4°Cfor15daysasfreshcutproducts.
Closedandopensymbolsrepresentfirst(C1)andsecondcut(C2)duringthegrowth,respectively.
Eachvalueisthemean(±SD)ofthreereplicates.Meanshavingthesameletterarenotsignificantly
differentatp=0.05followingtwowayANOVAwithstorage(S)andcut(C)asvariables.Fvaluesfor
maineffectsandtheirinteractionsignificantatp<0.001(***).Theantioxidantcapacityvalueswere
expressedasTroloxequivalents(TEAC)g
–1
FW.
4.Conclusions
Thepresentdatasetrevealedthatsorrelleaveshadahigherantioxidantcapacityandahigher
levelofbioactivecompoundsthanthosecommonlyobservedinotherleafyspeciestraditionallyused
asfreshcutproducts.Thiswasalsoassociatedwithagoodshelflifeintermsofnutraceuticalstability
duringcoldstorage.Therefore,R.acetosacouldbeaninteresting“new”leafyspeciestobeusedasa
leafy,freshcutproduct.Inaddition,therewasahigherlevelofnutraceuticalsinleavesobtainedfrom
C1thaninleavesobtainedfromC2,eventhoughleavesfromC2showedamorestablepatternof
nutraceuticalcompoundcontentduringcoldstorage.Futurestudiesarethereforeneededtoreduce
thenutraceuticalvariabilitybetweenconsecutivecutsinordertostandardizetheyieldandthe
biochemicalprofileofsorrelleavesandtodetermineifthelightconditionsofstorage(asthefresh
cutproduceisusuallystored)orthemodificationofcompositionofthegasintheheadspaceofthe
packagingmaypromotechangesinbiochemicalattributesofsorrelleaves.
AuthorContributions:Theauthorscontributedtotheworkasfollows:Conceptualization,A.P.,C.C.,L.G.,L.I.,
andM.L.;methodology,investigation,formalanalysis,writingoriginaldraft,C.C.;reviewedandeditedthe
manuscript,A.P.,L.G.,L.I.,andM.L.;resourcesandfunding,A.P.andL.G.Allauthorshavereadandagreedto
thepublishedversionofthemanuscript.
Funding:TheworkwascofoundedbytheERBAVOLANTGoproject(RuralDevelopmentpolicy2014–2020
Measure16.2:SupporttotheOperationalGroupsofagriculturalEuropeanInnovationPartnership(EIPAGRI).
ConflictsofInterest:Theauthorsdeclarenoconflictofinterest.Thefundershadnoroleinthedesignofthe
study;inthecollection,analyses,orinterpretationofdata;inthewritingofthemanuscript,orinthedecisionto
publishtheresults.
References
1. Lee,N.J.;Choi,J.H.;Koo,B.S.;Ryu,S.Y.;Han,Y.H.;Lee,S.I.;Lee,D.U.Antimutagenicityandcytotoxicity
oftheconstituentsfromtheaerialpartsofRumexacetosa.Biol.Pharm.Bull.2005,28,2158–2161.
2. Guarrera,P.M.;Savo,V.Perceivedhealthpropertiesofwildandcultivatedfoodplantsinlocalandpopular
traditionsofItaly:Areview.J.Ethnopharmacol.2013,146,659–680.
3. Guarrera,P.M.;Savo,V.WildfoodplantsusedintraditionalvegetablemixturesinItaly.J.Ethnopharmacol.
2016,185,202–234.
Horticulturae2020,6,48of9
4. Kucekova,Z.;Mlcek,J.;Humpolicek,P.;Rop,O.;Valasek,P.;Saha,P.PhenoliccompoundsfromAllium
schoenoprasum,TragopogonpratensisandRumexacetosaandtheirantiproliferativeeffects.Molecules2011,
16,9207–9217.
5. Schunko,C.;Grasser,S.;Vogl,C.R.Explainingtheresurgentpopularityofthewild:Motivationsforwild
plantgatheringintheBiosphereReserveGrossesWalsertal,Austria.J.Ethnobiol.Ethnomed.2015,11,55.
6. Bicker,J.;Petereit,F.;Hensel,A.ProanthocyanidinsandaphloroglucinolderivativefromRumexacetosa
L.Fitoterapia2009,80,483–495.
7. Ceccanti,C.;Landi,M.;Benvenuti,S.;Pardossi,A.;Guidi,L.Mediterraneanwildedibleplants:Weedsor
“newfunctionalcrops”?Molecules2018,23,1–15.
8. MinistryofAgricultural,FoodandForestryPolicies.ItalianMinisterialDecreen.3746/2014.GazzettaUfficiale
dellaRepubblicaItaliana,12Agosto2014;MinistryofAgricultural,FoodandForestryPolicies:Rome,Italy,
2014.
9. Watada,A.E.;Qi,L.Qualityoffreshcutproduce.PostharvestBiol.Technol.1999,15,201–205.
10. Yano,M.;Saijo,R.Newpreservationmethodforshreddedcabbagewithspecialreferencetononbrowning
cultivar.J.Jpn.Soc.ColdReserv.Food1987,13,11–15.
11. Landi,M.;DeglʹInnocenti,E.;Guglielminetti,L.;Guidi,L.Roleofascorbicacidintheinhibitionof
polyphenoloxidaseandthepreventionofbrowningindifferentbrowningsensitiveLactucasativavar.
capitata(L.)andErucasativa(Mill.)storedasfreshcutproduce.J.Sci.FoodAgric.2013,93,1814–1819.
12. Orsini,F.;Fecondini,M.;Mezzetti,M.;Michelon,N.;Gianquinto,G.Simplifiedhydroponicfloating
systemsforvegetableproductioninTrujillo,Peru.InProceedingsoftheIIInternationalConferenceon
LandscapeandUrbanHorticulture,Bologna,Italy,9–13June2009.
13. Incrocci,L.;Lorenzini,O.;Malorgio,F.;Pardossi,A.;Tognoni,F.Valutazionequantiqualitativadella
produzionedirucola(ErucavesicariaL.Cav.)ebasilico(OcimumbasilicumL.)ottenutainsuoloefloating
systemutilizzandoacqueirriguecondifferenticontenutidiNaCl.ItalusHortus2001,8,92–97.
14. Cantos,E.;Tudela,J.A.;Gil,M.I.;Espín,J.C.Phenoliccompoundsandrelatedenzymesarenotratelimiting
inbrowningdevelopmentoffreshcutpotatoes.J.Agric.FoodChem.2002,50,3015–3023.
15. GarcíaGimeno,R.M.;ZureraCosano,G.Determinationofreadytoeatvegetablesaladshelflife.Int.J.
FoodMicrobiol.1997,36,31–38.
16. Wang,M.;Xu,Z.;Song,J.;Liu,X.;Jiao,X.Effectsofdifferentmowingtreatmentsandstubbleheightson
thecompensatorygrowthandqualityoflettuce(LactucasativaL.).J.Hortic.Sci.Biotech.2018,93,537–544.
17. Dewanto,V.;Adom,K.K.;Liu,R.H.Thermalprocessingenhancesthenutritionalvalueoftomatoesby
increasingtotalantioxidantactivity.J.Agric.FoodChem.2002,50,3010–3014.
18. Du,G.;Li,M.;Ma,F.;Liang,D.AntioxidantcapacityandtherelationshipwithpolyphenolandvitaminC
inActinidiafruits.FoodChem.2009,113,557–562.
19. Porra,R.J.;Thompson,W.A.;Kriedemann,P.E.Determinationofaccurateextinctioncoefficientsand
simulataneousequationsforassayingchlorophyllsaandbextractedwithfourdifferentsolvents:
Verificationoftheconcentrationofchlorophyllstandardsbyatomicabsorptionspectroscopy.Biochim.
Biophys.ActaBiog.1989,975,384–394.
20. Kampfenkel,K.;VanMontagu,M.;Inzé,D.Extractionanddeterminationofascorbateand
dehydroascorbatefromplanttissue.Anal.Biochem.1995,225,165–167.
21. BrandWilliams,W.;Cuvelier,M.E.;Berset,C.Useofafreeradicalmethodtoevaluateantioxidantactivity.
Lebensm.Wiss.Technol.1995,28,25–30.
22. Pernice,R.;Scuderi,D.;Napolitano,A.;Fogliano,V.;Leonardi,C.Polyphenolcompositionandqualitative
characteristicsoffreshcutlettuceinrelationtocultivar,mulching,andstorage.J.Hortic.Sci.Biotechnol.
2007,82,420–427.
23. Degl’Innocenti,E.;Pardossi,A.;Tognoni,F.;Guidi,L.Physiologicalbasisofsensitivitytoenzymatic
browningin‘lettuce’,‘escarole’and‘rocketsalad’whenstoredasfreshcutproducts.FoodChem.2007,104,
209–215.
24. Amodio,M.L.;Derossi,A.;Colelli,G.Modelingphenoliccontentduringstorageofcutfruitandvegetables:
Aconsecutivereactionmechanism.J.FoodEng.2014,140,1–8.
25. Bottino,A.;Degl’Innocenti,E.;Guidi,L.;Graziani,G.;Fogliano,V.Bioactivecompoundsduringstorageof
freshcutspinach:Theroleofendogenousascorbicacidintheimprovementofproductquality.J.Agric.
FoodChem.2009,57,2925–2931.
Horticulturae2020,6,49of9
26. Castaner,M.;Gil,M.I.;Ruiz,M.V.Browningsusceptibilityofminimallyprocessed‘Baby’and‘Romaine’
lettuces.Eur.FoodRes.Technol.1999,209,52–56.
27. Ferrante,A.;Incrocci,L.;Maggini,R.;Serra,G.;Tognoni,F.Colourchangesoffreshcutleafyvegetables
duringstorage.J.FoodAgric.Environ.2004,2,40–44.
28. Matile,P.;Schellenberg,M.;Vicentini,F.Localizationofchlorophyllaseinthechloroplastenvelope.Planta
1997,201,96–99.
29. Bergquist,S.Å.M.;Gertsson,U.E.;Olsson,M.E.Influenceofgrowthstageandpostharveststorageon
ascorbicacidandcarotenoidcontentandvisualqualityofbabyspinach(SpinaciaoleraceaL.).Sci.FoodAgric.
2005,86,346–355.
30. Tsironi,T.;Dermesonlouoglou,E.;Giannoglou,M.;Gogou,E.;Katsaros,G.;Taoukis,P.Shelflifeprediction
modelsforreadytoeatfreshcutsalads:Testinginrealcoldchain.Int.J.FoodMicrobiol.2017,240,131–140.
31. Phillips,K.M.;TarragoTrani,M.T.;McGinty,R.C.;Rasor,A.S.;Haytowitz,D.B.;Pehrsson,P.R.Seasonal
variabilityofthevitaminCcontentoffreshfruitsandvegetablesinalocalretailmarket.Sci.FoodAgric.
2018,98,4191–4204.
32. Zujko,M.E.;Witkowska,A.M.Antioxidantpotentialandpolyphenolcontentofselectedfood.Int.J.Food
Prop.2011,14,300–308.
33. Kongwong,P.;Boonyakiat,D.;Poonlarp,P.Extendingtheshelflifeandqualitiesofbabycoslettuceusing
commercialprecoolingsystems.Posthar.Biol.Tecnol.2019,150,60–70.
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... An increase in leaf TPC after consecutive cuts was also reported in rocket and spinach by Bantis et al. [50], in basil by Ciriello et al. [51], in R. acetosa by Ceccanti et al. [52], in S. minor [31] and in other leafy vegetables [53], in agreement with our findings in B. officinalis and M. sylvestris. Indeed, the accumulation of bioactive compounds represents a means by which plants counteract the production of oxygen reactive species (ROS) induced by different stresses such as drought, excess light and wounding [54][55][56]. ...
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本研究では, 褐変しにくい品種を利用することによって, カットキャベツの品質保持法の改善を試みた。(1) 供試品種はカット後の褐変程度 (1×1mmのみじん切り20℃24時間静置の条件で調査) によって3段階に分類され, ΔE (Lab) が4未満で褐変しにくかったのが, “銀力” など2品種, 軽度の褐変のΔE (Lab) 4以上, 10未満の品種が “グリーンボール” など8品種, 激しい褐変のΔE (Lab) 10以上は “夏峰” など18品種であった。(2) 最も褐変しにくい品種であった “銀力” は初夏採り・早期収穫で最もその特性が顕著であった。(3) カットキャベツ (“夏峰”) をポリエチレンフイルム (PE) 袋密封包装で5℃, 10日間貯蔵した所, 包装内の炭酸ガスは8.5%まで上昇し, 酸素は1.5%まで減少し, 異臭が発生した。これに対して, 有孔PE袋包装では酸素の減少はわずかで, 異臭は発生せず, 褐変が認められた。(4) PE袋密封貯蔵ではカットキャベツの品質保持期間の品種間差異は認められなかった。有孔PE包装では, 品質保持期間はその品種の褐変しやすさによって大きく変動した。 “銀力” を有孔PE袋包装した場合の品質保持期間は5℃で10日と, 有孔あるいは無孔袋包装した他のどの品種より長かった。