Download to learn more about the health benefits of fermented goat dairy

Happy Days Dairies Ltd.
Article # 7 - Properties and Benefits of Fermented Dairy Products
By Sarah Holvick, B.Sc. Nutrition
Released March 17, 2014
Happy Days Dairy Ltd.
691 Salmon River Road
Salmon Arm, BC
V1E 3E9
250-832- 0209
[email protected]
www.happydaysdairy.com
Table of Contents
Introduction................................................................................................................... 3
Fermentation and End Products................................................................................... 3
The Biochemical Process of Fermentation .................................................................. 4
Yogurt .......................................................................................................................... 5
Cheese ..........................................….......................................................................... 6
Kefir …......................................................................................................................... 6
Technological Difficulties or Producing Fermented Goat Milk Products....................... 6
Health Benefits of Fermentation…............................................................................... 6
Hypotensive Peptides ….............................................................................................. 7
Antimicrobial Activity …................................................................................................ 7
Gastrointestinal and Urogenital Health ........................................................................ 7
Antioxidative and Anticarcinogenic Effects ................................................................. 8
Allergy Management …............................................................................................... 8
Conclusion ................................................................................................................... 9
References ................................................................................................................ 10
Article#7-PropertiesandHealthBene itsofFermentedDairyProducts
By:SarahHolvik,B.Sc.Nutrition
Goatmilkisanutritionalandtherapeuticfood.Theuniqueandbene icial
characteristicsofthisdairyalternativethataresuperiortocowmilkhavebeen
previouslydiscussed,andinclude:betterdigestibility,greaterbufferingcapacity,fat
globulesthataresmallerindiameterandbetterdistributedinthemilkemulsion,
highercontentofshort-chainfattyacidsinthemilkfat,highercontentofzinc,iron
andmagnesium,strongerlactoperoxidase(antimicrobial)systemaswellasbetter
immunologicalandantibacterialproperties.Thegreateramountsofcertain
mineralssuchascalcium,zincandmagnesiumingoatmilkmayalsoin luenceand
facilitatethegrowthoflacticacidbacteriaastheyareanormalpartofsome
enzymaticcomplexesinvolvedinthefermentationoflactose.Furthermore,the
higherwheyproteincontentcouldalsobesigni icantbecauseLactobacillus
acidophilusandBi idobacteriagrowmorereadilyinthepresenceofhigherlevelsof
someaminoacids.Fermentationisknowntoamplifytheexistingbene icial
propertiesofdairyproducts,andfermentedgoatmilkalternativeshavebeenshown
tohavegreathealthadvantages,includinganti-allergenic,probioticandanticarcinogenic.Ithasalsobeenshownthatnutritivevalueofgoatmilkincreases
duringfermentationandthatitlosesitscharacteristic“goaty”taste,whichis
unacceptabletomanyconsumers(Slancanacetal.,2010).
Fermentation&EndProducts
Foodspoilagecausedbymicroorganismswasanimportantproblemthroughout
humanhistory.Findingwaystoovercomethisissuebecameincreasinglynecessary
ascommunitiesexpandedandnoteveryoneproducedtheirownfood.Asaresult,
preservationmethodssuchassalting,drying,canningandpasteurizationwere
developedinordertodelayfoodspoilage.Fermentationwasalsodiscoveredearly
ontobeagoodmethodforpreservationbyusingthegrowthofcertain
microorganismsinfoodasanadvantage.Thefermentationprocesshasbeenshown
toincreasethenutritivevalueofdairyproducts.Table1showstheincreasein
variouscomponentsincowandgoatmilks,demonstratingthatthelattercontains
higheramountsofbene icialorganicacidsbothbeforeandafterfermentation.
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Table1.Organicacidproductionduringfermentationofgoatandcowmilks
(Slacanacetal.,2005)
TheBiochemicalProcessofFermentation
Fermentationreferstothemetabolicprocessbywhichmicrobesproduceenergyin
theabsenceofoxygenandotherterminalelectronacceptorsintheelectron
transportchain.Allorganismsneedenergytogrow,anditisknownthatthisenergy
comesfromthereductionofadenosinetriphosphate(ATP)toandenosine
diphosphate(ADP),resultinginthereleaseofenergyandaphosphategroup.Cells
obtainATPfromthechemicalbreakdownofglucosetoformtwomoleculesof
pyruvate,alsoknownasglycolysis(Figure1).AlthoughthisprocessrequiresATP,it
resultsinareleaseoffourmoleculesforanetgainoftwoATPmolecules.Once
pyruvateisformed,itcanbeprocessedaerobically(inthecaseofmammaliancells),
oranaerobically(inthecaseoffermentation).Twoofthemostimportant
fermentationprocessesthatareusedonanindustrialscaleareethanolorlacticacid
fermentation(Figure1).
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Figure1.Glycolysisandfermentation
(Yim&Glover,2003)
Yogurt
Yogurtisproducedthroughthefermentationofmilkbylacticacidbacteria,usually
lactobacillusbulgariusandStreptococcusthermophilus.Milkisusually irstheated,
homogenizedandisthencooledinorderforthestartercultureorbacteriatobe
added.Thebacteriathenusethelactoseinmilkasafoodsourceforthe
fermentationprocess,generatinglacticacidasaresult.LacticacidlowersthepHof
theyogurttherebyactingasapreservativesincemostpathogenicbacteriacannot
growinacidicconditions,makesittart,andcausesthemilkproteinstocoagulate
andset,formingyogurt.
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Cheese
Cheeseisfermentedmilk,whichhasaportionofitswaterandlactoseremoved.
Thereare4basicstepstomakingcheese:curdling,draining,pressingandripening.
Curdlingiswhentheliquids(whey)areseparatedfromthesolids(curds)bythe
additionofafermentingagent.Cheesethenundergoesdraining,wherethewheyis
eliminatedfromthecurd.Thisstepisimportanttoattainthecorrectmoisture
contentinthecheese.Pressingoccursnext,inordertoeliminatemorewhey.Finally,
thecheeseisripenedandtakesonitsuniquecharacteristicsof lavour,textureand
aroma.
Ke ir
Traditionally,thefermentationofke irwasdoneathomeasamechanismto
preservemilkbeforetheadventofrefrigeration.Nowadays,thecommercial
productionofke irstartswiththepasteurizationofmilkinordertokillbacteriathat
cancauseunwantedspoilageoftheendproduct,whichisheat-treatedinorderto
denaturethewheyproteins.Theproductisthencooled,andke irgrainsorculture
areadded.Theke ircultureisknownas“grains”becauseitformsgrain-likecasein
polysaccharide-microorganismparticlesduringfermentation.Oncetheculturehas
beenadded,themixtureisincubatedfor24hoursbeforetheyareremovedandthe
productispasteurized,chilledandpackaged.
TechnologicalDif icultiesofProducingFermentedGoatMilkProducts
IntheEuropeanUnion,goatmilkproductsareconsideredtobethedairyproduct
withthegreatestmarketingpotentialand,therefore,severalcharacteristicsofgoat
milkarecurrentlythefocusofincreasedresearchinterest.However,alongsidethe
nutritionalandtherapeuticadvantagesofgoatmilkanditsfermentedproductsin
particular,therearealsosometechnologicaldif icultiesassociatedwiththe
productionoffermentedgoatmilkwithgoodsensoryproperties.Themajorityof
theseissuesareassociatedwiththespeci iccompositionandstructureofgoatmilk.
Asgoatmilkhasaslightlylowercaseincontentthancow'smilk,withaverylow,or
sometimesevenabsentamountofαS1-casein,andahigherdegreeofcaseinmicelle
dispersion,theconsistencyoffermentedgoatmilkproductshasbeendeterminedto
beoneofthecriticalproblems.Inaddition,seasonalchangesinthecompositionof
goatmilkalsoin luencetheconsistencyoffermentedproducts.Thesefactors
in luencethecurd-formingpropertiesinfermentedgoatmilk,whichismuchweaker
thanthatofcowmilk.Furthermore,anotherproblemisover-acidi icationof
fermentedgoatmilkproductsincomparisonwiththoseofcowmilk(Slancanacet
al.,2010).
HealthBene itsofFermentation
Wehavediscussedthebene icialpropertiesofgoatmilk,makingthisdairyproduct
superiorintermsofhealthbene itsincomparisontocow'smilk.Theadditional
bene itsoffermenteddairyproductsarealsoknown,thereforeitmaybesaidthat
fermentedgoatdairyproductsexertgreaterhealthadvantages.
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Hypotensivepeptides
Thefermentationoftheproteinsinmilkbylactic-acidbacteriamayresultinthe
releaseoftripeptideswithbloodpressureloweringactivities.Twoofthesepeptides,
isoleucylprolyl-proline(Ile-Pro-Pro)andValyl-Prolyl-Proline(Val-Pro-Pro)have
beenisolatedconsistentlyfromcaseindigestsandhavebeenshowntolowerblood
pressureinspontaneouslyhypertensiveratsandinhumanswithmildhypertension.
Inanotherstudy,middle-agedsubjectswithmoderatehypertension(systolic
readingsbetween140and180mmHganddiastolicreadingsbetween90and110
mmHg)received150mlofamilkfermentedwithL.helveticusLBK-16H,twicedaily
for16weeks,with7.5mg/100gofIle-Pro-Proand10mg/100gofVal-Pro-Pro.The
controlgroupreceivedthesameproductastheexperimentalgroupbutwithoutthe
twoactivepeptides.Bloodpressurewasmonitoredatthebeginningandattheend
ofthetrialwithanautomatic,24-hourpressurerecorderand,inadditionevery
participantwassubjectedtoninebloodpressurecontrolsatregularpredetermined
intervals.Theresultsshowedthattherewasadifferenceof0.9mmHginthesystolic
pressureanda-1.8mmHgbetweentheL.helveticusandthecontrolgroups,
respectively.Thiskindofareductioninbloodpressureisconsidered
epidemiologicallysigni icantintermsofpublichealth.
Furthermore,invivoandinvitroACE-inhibitoryactivityoriginatingfromthe
fractionationofcaseinshasbeendetectedinmilkproductsusingdifferentbacterial
strainsduringfermentation.ACEisoneofthemainbloodpressure-regulating
moleculesasitisabletosynthesizeangiotensinII,apotentvasoconstrictor.
Furthermore,thisprocessofangiotensinIIsynthesisinducesbradykinin
degradation,whichisapowerfulvasodilator.Therefore,theoveralleffectof
inhibitingACEresultsinaloweringofbloodpressure.Astudyongoat'smilkke ir
detectedthepresenceofACE-inhibitorypeptidesthatshowedanti-hypertensive
activity,twoofwhichwereparticularlypotent.Thedigestionwithgastricand
pancreaticenzymesfurtherhydrolyzedtheoriginalpeptidesandsomeofthe
resultingproductsalsoexhibitedvasomotoreffects(Brunseretal.,2007).
Antimicrobialactivity
Aswehavementionedinapreviousarticle,manybioactivepolypeptideshavebeen
identi iedinencryptedforminmilkproteins,whicharereleasedduring
fermentationand/orduringdigestionoftheseproteinsbythegastricandpancreatic
enzymesinthegastrointestinaltract.Thesepeptidesincludefamiliesorsingle
peptidescalledcaseicidins,isracidins,andlactoferrin,whichhavetheabilitytolyse
pathogenicbacteriaincludingStreptococcusmutans,E.coliO157:H7and
Enterobacterzakazakii.Thelaterhasbeenrecognizedastheetiologicalagentofa
formofneonatalmeningitis(Brunseretal.,2007).
Gastrointestinalandurogenitalhealth
Therehavebeennumerousstudiesconductedinordertodeterminetheeffectsof
fermentedgoatmilkontheinhibitionofvariousintestinalandurogenitalpathogens.
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Forexample,Slacanacetal(2004)investigatedtheeffectsoffermentedmilkon
urogenitalpathogeninhibitionandfoundaconsiderablyhigherinhibitoryeffectof
goatmilkfermentedwithB.longumonthegrowthofC.albicanscomparedwiththat
offermentedcowmilk.Similarly,Pavlovicetal.(2006)analysedtheantagonistic
actionofgoatandcowmilkfermentedwithB.longumBb-46onthepathogenic
organismsSerratiamarscensesandCampylobacterjejuni.Theirresultsalsoshoweda
greaterinhibitoryeffectoffermentedgoatmilk.
AChileanstudyinvestigatedtheeffectsofamilkformulaacidi iedbytheadditionof
L.helveticusandS.thermophileson82weanedinfantslessthan12monthsofagefor
a6-monthperiod.Inaddition,agroupof104infants,comparableintermsofthe
anthropometricandsocio-economicpointsofview,andwhoreceivedtheirmedical
careinanearbyareaservedascontrolsandreceivedanon-fermentedmilkof
similarcomposition.Thefermentedmilkdemonstratedaclearpreventiveeffect
againstnewepisodesofdiarrhea,astheincidence,durationandfrequencyof
recurrenceweresigni icantlylowerinthisgroup.Similarly,variousspeciesand
strainoflacticacidbacteriahavebeenevaluatedfortheirabilitytomodifythe
courseofviraldiarrhea,andL.rhamnosusGG(LGG)hasbeenthemostextensively
tested,especiallyforitseffectsondiarrheaassociatedwithrotavirusinfectionin
children.Whenadministeredinassociationwithfermentedmilk,asigni icant
shorteningoftheevolutionofthediseasewasobservedincomparisontothecontrol
group(Brunseretal.,2007).
Antioxidativeandanticarcinogeniceffects
Kullisaaretal.(2003)studiedtheantioxidativeeffectsofafermentedgoat'smilk.
Theyassignedtwenty-onehealthysubjectstotwotreatmentgroups:goat'smilk
groupandfermentedgoat'smilkgroup(150g/d)fortwenty-onedays.Consumption
ofthefermentedgoat'smilkimprovedanti-atherogenicityinhealthysubjects,
prolongedresistanceofthelipoproteinfractiontooxidation,loweredlevelsof
peroxidizedlipoproteins,oxidizedLDL,andglutathioneratio,andenhancedtotal
antioxidativeactivity.Furthermore,thesubjectsreceivingthefermentedgoat'smilk
groupshowedanalteredprevalenceandproportionoflacticacidbacteriaspeciesin
thegutmicro lora.
Animalfoodproducts,particularlydairyproducts,arerichinconjugatedlinoleic
acid(CLA).CLAisknowntopossessanti-carcinogenic,atherosclerosisinhibiting
andbodyfatreducingproperties,andhenceitsconsumptionisconsideredtohave
healthbene itingeffects.Indratiningsihetal.(2012)investigatedtheeffectof
fermentationonchangesintheCLAcontentingoatmilk.Theresultsdemonstrated
thatthefermentationprocessincreasedtheCLAcontentofgoatmilkfrom3.09
mg/gfatinfreshmilkto3.26mg/gfatinfermentedmilk.
Allergymanagement
Anumberofstudieshaveshowntherelationshipbetweenallergicconditionsand
thecompositionofthegutmicrobiota.Thelevelsofbi idobacteriainstoolsfrom
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allergicinfants,particularlythosewithatopiceczema,aresigni icantlylowerthan
thoseinhealthysubjects.Therefore,ithasbeenproposedthattheintakeof
fermentedproductscontaininglacticacidbacteriacouldbeusedtoachieve
homeostasisofthegutmicrobiotaandtherebydecreasethesymptomatologyin
infantsatriskforallergy(Brunseretal.,2007;Gilliland,1999).
Conclusion
Fermenteddairyproductshavealonghistoryofbeingimportantdietary
componentsforhumans,andthemorerecentapplicationofmodernresearch
methodologiesisshowingthatthebacteriaandtheproductsofthefermentation
processparticipateinavarietyoffunctionsthatarepositiveforhealthandwellness
ofallagegroups.
References:
Brunser,O.,Gotteland,M.,Cruchet,S.Functionalfermentedmilkproducts.Nestle
NutritionWorkshopPediatricProgram.2007;60:235-247.
Gilliland,S.E.Technological&CommercialApplicationsofLacticAcidBacteria;
Health&NutritionalBene itsinDairyProducts.Availableat:
ftp://ftp.fao.org/es/esn/food/Gilli.pdf
Howcheeseismade.Availableat:http://www.dairygoodness.ca/
Indratiningsih,S.,Djojowidagdo,Z.,Bachruddin,Z.,Widyobroto,B.P.Conjugated
st
LinoleicAcid(CLA)ContentinFermentedGoatMilk.1 AsiaDairyGoatConference.
2012;9-12.
Kullisaar,T.,Songisepp,E.,Mikelsaar,M.,Zilmer,K.,Vihalemm,T.,Zilmer,M.
Antioxidativeprobioticfermentedgoats'milkdecreasesoxidativestress-mediated
atherogenicityinhumansubjects.BritishJournalofNutrition.2003;90:449-456.
Nummer,B.A.FermentedFoods:Ke ir.Availableat:
http://nchfp.uga.edu/publications/nchfp/factsheets/ke ir.html
Slacanac,V.,Bozanic,R.,Hardi,J.,Szabo,J.R.,Lucan,M.,Krstanovic,V.Nutritionaland
therapeuticvalueoffermentedgoatmilk.InternationalJournalofDairyTechnology.
2010;63:1-19.
Slacanac.V.,Hardi.J.,Pavlovic.H,,Vukovic,D.,Cutic.V.Inhibitoryeffectofgoatandcow
milkfermentedbyABT-2culture(LactobacillusacidophilusLa-5,Bi ido-bacterium
lactisBb-12andStreptococcusthermophilus)onthegrowthofsomeuropathogenic
E.colistrains.ItalianJournalofFoodScience.2004;16:209–219.
Yim,G.,Glover,C.Foodmicrobiology:thebasicsandthedetailsofcheeseproduction.
TheScienceCreativeQuarterly.2003;8:1-3.
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