2024年一條乳基與植物基酸奶的混合生產(chǎn)線白皮書（英文版）-Tetra Pak

Whitepaper

Dairyandplant-based yoghurtproductiononasinglehybridline

General

Publisher

TetraPakProcessingSystemsABSE22186Lund,Sweden

Published

May2024

?TetraPakInternationalS.A

Nopartofthispublicationmay

beduplicatedinanyformwithoutthesourcebeingindicated.

3

CONTENTS

INTRODUCTION 4

Whoisthiswhitepaperfor? 4

Whereareyounow? 5

Whatyou’lllearn 6

Yoghurtterminologyandthelaw 6

FERMENTEDPRODUCTS–GROWTHOPPORTUNITIES 7

Globalyoghurttrends 7

Newopportunities 9

WHATDAIRYANDPLANT-BASED 10

YOGHURTPRODUCTIONHAVEINCOMMON 10

Howrawmaterialsandingredientsaffectprocessing 12

WHATMAKESALINE“HYBRID”–CAPABLEOFBOTHDAIRYANDPLANT-BASED

PRODUCTION? 16

Extraction 16

Productformulation 18

Heattreatment 19

Startercultureadditionandfermentation 21

Smoothing&cooling 22

Buffering,fruitdosing&filling 22

Extraprocessingstepsforambientproducts 23

CLEANINGINPLACE(CIP) 24

ALLERGENSANDPRODUCTCHANGEOVERS 25

HYBRIDLINES–INSUMMARY 28

TETRAPAK–YOURGO-TOPARTNERFORYOGHURTPRODUCTINNOVATION 29

REFERENCES31

4

INTRODUCTION

Whoisthiswhitepaperfor?

Therearemanydiverseindustrygroupswhoareinterestedinbroadeningtheirknowledgeoffermentedplant-basedfoodsandbeverages,inparticularyoghurtproducts,inordertoexpandtheirproductioncapabilitiesandproductflexibility.Weseethatmanydairyproducersareinterestedinplant-basedproducts,in

keepingwithcurrentmarkettrends.

Thusthiswhitepaperistargetedtoanyproducerwhowantstoproducebothdairy-basedandplant-basedyoghurtproductsonasinglehybridline.The

principleswelayoutapplybothtonewlinesandtheadaptationofexistinglines.Inbothcases,thereistheaddedbenefitoffuture-proofingyouryoghurtproductionbyincreasingflexibility,butalsochallengessuchastheriskofallergencross-

contamination.

Thiswhitepaperhasbeenwrittenfor:

?Marketingmanagerswhoaimtolaunchnewproductformulations,expandconsumerappeal,andmaintainflexibilityintheirproductportfolio

?Productionmanagersconcernedwithproductivity,efficiencyandflexibilityofproductionlines

?R&Dmanagersresponsibleforcreatingnewformulationsandproducts

?Projectmanagersresponsibleforinstallinganewplant,oradaptingexistinglines

?Qualityassurancemanagers

?Environmentalandsafetymanagersconcernedwithenvironmentalimpacts,sustainabilityissues,productsafetyandconsumersafety–especiallyregardingallergens.

5

Whereareyounow?

Ifyouarealreadywellestablishedintraditionaldairyproduction,youhavealreadymasteredmanyofthehygienicaspectsandhaveagoodsenseofdairyyoghurt

production.Thiswhitepaperwillfillthegapsinyourfoodtechnologyknow-howsothatyouareabletostartworkingwithplant-basedyoghurtproducts.

Thiscanbechallenging,becauseplant-basedfermentationproductionhasn’tyetachievedthedegreeofstandardisationandefficiencythatiswellestablishedinthedairyindustry.Thisispartlybecauseofthehugevarietyofrawmaterialsandpartlybecauseitisarelativelyyoungproductcategory.

Asaresult,thereisstillalottobedonetoestablishbestpracticesforproduct

qualityandprocessingefficiency.Makingtheleaptoplant-basedyoghurtwillalsoinvolveunderstandingthevaryingcompositionandfunctionalityofrawmaterialsandingredientssuchasthickeners,andhowtheseingredientsareimpactedby

differentprocessingsteps.

Finally,ifyouareanewcomertothefoodindustry,buthavecreativeideasfornewfermentedfoods,thiswhitepaperwillprovidetheoverviewyouneedtomove

aheadwithyourplans.

6

Whatyou’lllearn

Thismaterial,developedbyourdairyandplant-basedprocessingexperts,putsour

combinedknowledgeatyourdisposal,providingyouwithacompetitiveedge.Itwillhelpyouunderstandhowtheproductionprocessesrequiredfordairyand

plant-basedproductsdiffer,howtheydependoninputcharacteristicsand

formulations,andhowtomakeadjustmentstooptimiseproductionofbothtypesofproducts.Thisincludesreviewing:

?Thetechnologyandequipmentinvolved–capabilities,challengesandsolutions

?Thecompromisesandriskmanagementinvolvedininvestingandrunninga

“hybridline”–whatdecisionsdoyouhavetomake,andwhatistheimpactofthesedecisions?

?Thetechnologyrequirementsatanearlystageofdesign,whichcanreduceyourtimetomarketandinvestmentcosts,thusreducingtherisk.

Withmorethan100yearsofexperienceindairyproductsandmorethan40yearsinplant-basedproduction,wearereadytoshareourknowledgewithyou.

Yoghurtterminologyandthelaw

Terminologyisimportant.Whenwerefertoplant-basedyoghurtinthiswhitepaper,wemeanfermentedplant-basedproductsthataresimilarintaste,appearance,andtexturetotraditionaldairy-basedyoghurt.Butpleasenotethatinmanymarketstheterm“yoghurt”isreservedfordairyproducts,soinsomemarkets,producersareexperimentingwithotherlabelsfornewproductlines,suchthenovelword“gurt”.Youshouldverifyyourownmarketandlegalrequirementsbeforedecidingwhichtermtouseincommunicationsandadvertising,whenreferringtoplant-basedyoghurtproducts.

7

FERMENTEDPRODUCTS–GROWTHOPPORTUNITIES

Globalyoghurttrends

Whetherdairy-basedorplant-based,fermentedfoodssuchasyoghurtsand

yoghurt-likeproductsareincreasinginpopularityworld-wide.Theglobalyoghurtmarketforalltypes,includingbothdairyandplant-based,andrangingfromplainyoghurttoflavouredyoghurtdrinks,wasvaluedat$98bnin2020.Itisprojectedtogrowto$172bnby2031withacompoundannualgrowthrate(CAGR)of5.5%from2022to2031.EvenstrongergrowthisseeninIndia,wherethemarketisexpectedtogrowataCAGRof7.4%to2031,tolargeextentduetotheindustrialisationof

fermentedproductstraditionallymadeathome.

Theincreasinginterestinyoghurtproductsislargelydrivenbythehealthbenefitsassociatedwiththetraditionaldairyproduct,suchas:

?Dairyproductsnaturallycontainhighqualityproteinincludingallessentialaminoacids,andtheincreasedcontentinmanyyoghurttypesmakeitagreatsource

ofprotein.

?TheyaregoodsourcesofcalciumandvitaminsDandB12.

?Theycontainlivebacteria,whichhasapositiveimpactonimmunityandguthealth.

Healthisakeydriverforincreasedyoghurtconsumption,inparticularamong

youngerpeopleseekingtomaintainahealthierlifestyle.Tomeetconsumer

demand,plant-basedyoghurt-likeproductsareoftenformulatedtomimicthehealthbenefitsofyoghurt,ensuringthattheyareinmanywaysanalternativetotraditionaldairyproducts.

Themarketgrowthinyoghurtgoeshand-in-handwithanincreasedvarietyof

products,andproducersmustprovideacontinuouslybroaderproductassortment.Thehighinnovationratealsoleadstoamoveintopremiumproductranges,

allowingproducerstocommandhigherconsumerprices.Forinstance,yoghurtsarenowalsoseenasanindulgenceproduct,beingconsumedasdessertseveninmarketswheretheyweretraditionallyonlyusedasaningredientincooking.

8

Whytheinterestinplant-basedyoghurt?

Themarketforplant-basedyoghurtproductsisgrowingevenfasterthandairy-based,forreasonsthatrangefromnutritionalandeconomictoregulatoryandenvironmental.Theglobalmarketisforecasttoexceed$5bnby2030,reflectingaCAGRof10%between2020and2030.

Consumersareincreasinglyawareoftheimpactoftheirdietonphysicaland

mentalhealth,andthereforelookforalternativestomanytraditionalfood

products.Consumerswillcontinuetoseekoutproducts–bothdairyandplant-

based–thatbalancetheirintakeofcarbohydrates,proteinsandothernutrientsinawaythatenhancestheirhealth.Andplant-basedproductsaresuitableforthe

growingnumberofpeoplefollowingveganlifestyles.

Manyconsumersarechoosingmoresustainableproducts,withtheaimtofight

climatechangebyreducingtheirenvironmentalimpact,evenifthismeanspayingapremiumforenvironmentallyfriendlybrandsandproducts.Theenvironmentaleffectsofgreenhouseemissionscomingfromthedairyindustryareunder

particularscrutiny.Inmanycasesthismeansthatplant-basedproducts,intheir

roleas“dairyalternatives”areoftenperceivedasnotonlygoodfortheconsumerbutalsogoodfortheplanet.However,itisimportanttoconsiderthefullvalue

chainwhenevaluatingafoodproduct’simpactontheenvironment,asconsumerswillvaluesomeplant-basedproteinsmorethanothersduetotheirlower

environmentalfootprint.Wemustconsidertheenvironmentalimpactofachievingagivennutritionalvalue,butalsohowandwheredifferentrawmaterialsare

produced.

9

Newopportunities

Weareseeingtheconfluenceofseveraltrendshere:tastyproductstargeting

healthconcerns,plant-baseddiets,sustainability,andanimalwelfare.Plant-basedproductsmaybeconsumedaspartofanymealduringtheday,justlikedairy

products.

NorthAmericaandEuropearerapidlydevelopingmarketsforplant-based

productsingeneralandplant-basedyoghurtinparticular.Butthereisalsoalongtraditionandsignificantgrowthofplant-basedproductsinEastAsia(particularlybasedonsoya),andthesethreecombinedmarketsaccountfor65%ofglobal

production.

ResearchbythePlantBasedFoodsAssociationintheUSshowthat35%of

Americansareactivelydecreasingtheirdairyandmeatconsumption.Andthe

increasinghealthconsciousnessofconsumersisresponsiblefortheincreasein

veganismintheAsiaandPacificmarkets,againgivingopportunitiestogrowplant-basedyoghurtconsumption.

TheMiddleEastandAfricaarealsoseenasdevelopingmarketsforplant-based

yoghurts.Thereisageneralgrowthintheavailabilityofconveniencefoodsinthesemarkets,whichishelpingcreateanopportunityforthelaunchofnew,innovativeproducts.

10

WHATDAIRYANDPLANT-BASED

YOGHURTPRODUCTIONHAVEINCOMMON

Yoghurtexistsinalmostendlessvarieties.Everythingfromlow-viscous,almost

milk-likeanddrinkable,tothick,mouldabletexturescanbeproducedbyvaryingtheproductionprocess.Thoughmostyoghurtsarechilledproductscontainingliveandactiveyoghurtbacteria,therearealsoproductsthatareheat-treatedafter

fermentation,sothattheycanbestoredanddistributedatambientconditions(oftenreferredtoas“thermisedyoghurt"or“ambientyoghurt”).

Themostcommontypeofchilledyoghurtproductionprocessisthatof"stirred-type"yoghurt,aimedatpreservingasmuchtextureaspossibleintheyoghurt,whilesimultaneouslygivingtheproductaspoonable,shinyandhomogeneousconsistency.

Atfirstglance,theproductionlinesusedforstirreddairyyoghurtandplant-basedyoghurtproductslookverysimilar.Insomecases,particularlyiftheplant-based

productisbasedonaconcentrate(“paste”,“compound”or“syrup”),theymight

evenappearidentical,anditisonlywhenwefocusonspecificprocessingsteps,

designdetailsandparameters,thatthedifferentneedsandrequirementsoftheseproductsbecomeclear.

Butlet’sstartwithcommonalities:

Whileitispossibletofermentthemilkortheliquidplantbaseusingonlyastarterculture,otheringredientsareoftenaddedtoinfluencethecomposition,flavour,texture,stabilityandviscosityofthefinalproduct.Thisformulationoftheliquidisoftendonebymixing.

Theformulatedliquidisheatedbeforefermentation.Whiletheheattreatmentcanhaveaslightlydifferentoverallpurposefordairyandplant-basedproducts,inbothcasesitensuresthatthefinalproductissafetoconsume,aswellaseliminates

microorganismsthatmightotherwisecompetewiththestartercultureduring

fermentation.Homogenisationisappliedasapartoftheheattreatment,uniformlydecreasingthesizeoffat/oildropletsintheliquid.

Afteraddingthestarterculture,theproductislefttofermentforanumberofhoursuntilthedesiredpHlevelisreached.Inadditiontoacidity,thefermentingcultureproducesaromacompoundsthatcontributetotheflavourofthefinalproduct.

11

Inordertostore/buffertheproductbeforefilling,thefermentationissloweddownbycoolingtheproduct.Itisalsosimultaneouslysmoothedtogiveitamore

homogeneous,smoothertexture.Forflavouredproducts,fruitpreparationsor

aromasaredosedinlineintothefermentedproductasitispumpedintothefillingmachinefromthebuffertank,ordirectlyinthefillingmachine.

Finally,thefilledproductiscooledtorefrigeratortemperatureincoldstorage,fromwhichitcanthenbedistributedtoretailersunderchilledconditions,withashelf

lifeofaboutonemonth.

Plant-basedbase

Smoothing&cooling

Culturedosing

Formulation

Fermentation

Homogenisation&heattreament

Buffering

Filling

Fruitdosing

Figure1Exampleofproductionlineforplant-basedyoghurtforchilleddistribution

Alternatively,theproductcanundergoasecondheattreatmentafterfermentationandcooling,designedtoinactivatethefermentingbacteria.Followedbyultra-highhygienicorasepticfilling,thiscreatesaproductthatcanbestoredanddistributedatambienttemperatures,withashelflifeof4-12months.

Plant-basedbase

Smoothing&cooling

Culturedosing

Formulation

Fermentation

Homogenisation&heattreament

Heat

treatment

Buffering

Filling

Asepticbuffering

Figure2Exampleofproductionlineforplant-basedyoghurtforambientdistribution

12

Howrawmaterialsandingredientsaffectprocessing

Therearemanydifferenttypesofplantsthatcanbeusedtocreateplant-based

yoghurts,butthemostcommononestodayaresoyabeans,oats,almonds,coconutandpeas–andsometimesblendsofdifferentrawingredients.Someplant-based

proteinsaremorefavouredthanothersforfermentedproducts.Mouthfeeland

flavourareparamount:consumerslookforasmoothtextureandpleasanttaste.

Anotherissueistheirsuitabilitybasedonproteincontentandpotentialallergens;yetanotheristheirlocalavailabilityandenvironmentalimpactthroughoutthefullvaluechain.

Whatevertherawmaterial,theirparticularpropertieswillinfluencetherecipe,

processandfinalproduct.Milkisrichinbothprotein(~3.4%)andsugar(4.8%),whileoatbaseismainlyrichinsugarbutlowinprotein(therawoatitselfincludessomeproteinbutintheoat“base”extractedforfermentationthelevelislower).

Almonds,ontheotherhand,arerichinfatbutlowerthanmilkinbothproteinandcarbohydrates,andsoyabeansarerichinproteinlikemilkbutcontainlesssugarandfat.

14

12

10

8

6

4

2

0

Almond

frompaste

Soyafrom

Freshmilkorrecombined

Oats

grinding

fromflour/

kerns,treatedwithenzymes

Totalsolids%Proteins%Fat%Sugar/carbohydrates%

Figure3Examplesofmilkandplant-basedextractsthatcanbeusedforyoghurtproduction

13

Eveniftheproteinlevelisthesame,thetypeofproteincanbedifferent,

influencingthenutritionalaswellasfunctionalpropertiesoftheproduct.Andsomeproteinsareevenclassifiedasallergens,whichmeanstheycantrigger

allergicreactionsintheconsumer(readmoreaboutallergensinalatersection).

Plant-basedproductscancontainsmallparticlesofvarioussizes,suchasplant

fibres,dependingontheextractionprocess.Thiscanaffectmouthfeelandproductstabilityaswellasthechoiceofprocessingequipmentandtheeaseofcleaning

thatequipment.

Asmilkandplant-basedproductshavedifferentorigins,theyalsohavedifferentmicrobiologicalflora,whichcanaffect,forinstance,theheattreatmentprogramrequiredtocreateasafeproduct.

Addingyoghurtstarterculturetomilkresultsinfermentationandformationoftheproteinnetworkthatgivestheyoghurtitscharacteristictextureandappearance.

Evenso,itiscommoninmanycountriestoaddstabilisersandthickenersto

fermenteddairyproducts.Theseadditiveswillthencontributetothefinaltextureandstabilityoftheproduct.Theuseoftheseingredientsmightbemotivatedbycostoptimisation(replacingprotein/fatintheproductwithlessexpensive

components),orusedtoprolongshelflifebyimprovingproductstability(forinstanceinregionswithanunreliablecoldchain).

Fermentingliquidplantbasealoneusingastarterculturedoesnotautomaticallyresultinayoghurt-likeproduct.Infact,otheringredientsoftenneedtobeaddedtoaidthefermentationorinfluencetheflavour,textureandstabilityofthefinal

product.

?Ifthereisn’tsufficientsugarintheplantbasethismustbeadded(orcreatedthroughhydrolysingstarch)forfermentationtoproceed.

?Iftheproteinlevelislow,ortheproteinisofthewrongfunctionaltype,the

fermentedproductwillnothavetheviscoustextureassociatedwithyoghurt.

Theproteincontentcanbeboostedbyaddingproteinisolate,whilethickenersor

stabiliserscanbeaddedtocompensateforweakgel-formingability.Addingstarch,forinstance,haslongbeenapopularandrelativelyinexpensivemeansofproducingamoreviscoustexture.Moreandmoreproducersarefindingwaystocreate

productswithoutaddingstarch,butitisstillaverycommoningredient.

Insomecases,addingproteintoaplant-basedyoghurtisdoneforthesakeofthenutritionalproteincontentratherthanitsimpactontexture.

?Thefatleveloftheproductisoftenadjustedbyaddingoil/fattogiveafullerandsmoothermouthfeel.

14

Manyformulationsforplant-basedproductsalsocontainingredientslikemineralsandvitaminstoincreasethenutritionalvalueoftheproduct,aswellsaltandsugartoadjusttheflavour,eveninan“unflavoured”product.

Theactualstarterculturealsodiffersbetweendairyandplant-basedproducts.In

dairyproductsthefermentingstarterculturealwayscontainthesametwobacteria(StreptococcusthermophilusandLactobacillusbulgaricus)andinmanycountriestheuseofthesebacteriaisalegalrequirementforproductssoldas“yoghurt”.Theplant-basedproductsaregenerallylessregulated.Besidesensuringefficient

fermentation,manystarterculturesforplant-basedyoghurtsaimtocreateflavourcompoundssimilartothosefoundindairyproducts,eventhoughtherawmaterialisdifferent.Todaytherearealsostarterculturesavailablefortheplant-basedrangethatpartlycompensatefortheweakergel-buildingabilitiesoftherawmaterialbyhavingtexturisingpropertiesthemselves,makingitpossibletocreatethicker

textureswithouttheadditionofotheringredients.

Ingredientpropertiesmustbetakenintoaccountwhendesigningayoghurt

productionlineofanytype.Forinstance,warm-swellingstarchisoftenthemain

thickenerusedforplant-basedproducts.Dependingonthetypeandamountof

starchadded,theviscosityoftheproductcandevelopindifferentstages.AsFigure4shows,mostoftheviscositydevelopmentforadairyproducttakesplaceinthe

fermentationtank,andthenlaterduringthefirstdayofcoldstorage.Butforsometypesofplant-basedproductscontainingstarchthereisasignificantviscosity

increaseimmediatelyduringtheheattreatmentthatfollowstheformulation.

Othersbuildviscosityfirstinthefermentationtankornotuntiltheproducthasbeenfilledandplacedincoldstorage(comparethetwoplant-basedstarch

systemsinFigure4).Knowledgeoftheingredientsandthestarchsystemisthereforeessentialtothefinaldesignofaproductionlineandheattreatment.

15

Viscosity

Milk/baseFermentationBufferingPackagingStorage

Treatment

Plant-basedstarchsystem#1DairyPlant-basedstarchsystem#2

Figure4Exampleofhowdifferentstarchsystemsmayinfluenceproductviscositythroughouttheyoghurtprocessingline,comparedtothebehaviouroftypicaldairyyoghurt.

Theformulationofanambientfermentedproducthasdifferentrequirementsthanachilledfermentedproduct.Notonlydoesithavetodeliveranacceptableproductqualityafterthesecondheattreatment,butitalsohastoensurethatproduct

qualityremainsstableduringthesignificantlylongershelflifeexpectedofthe

product,andatambientstorageconditions.Thisisgenerallyachievedthroughtheadditionaldosageorchangeoftypeofstabilisersandthickenersincludedinthe

product.

Togetherthesebiologicalandchemicaldifferencesmeanthatrequirementson

processinglinesfordairyandplant-basedproductsaredifferent,whichweexplaininthefollowingsections.

16

WHATMAKESALINE“HYBRID”–

CAPABLEOFBOTHDAIRY

ANDPLANT-BASEDPRODUCTION?

Howcanayoghurtlinequalifyasahybridproductionline,capableofalternating

betweendairy-basedandplant-basedproduction?Inthissectionweintroducetheelementsofahybridlinestep-by-step,evaluatingeachprocessforhowithandlesdairyvsplant-basedmaterials,whatchallengesitmustmeet,andhowprocessingcomponentscanbeadaptedorconfiguredtoreachadesiredresult.

Extraction

Whiledairyyoghurtstartswithmilkinvariousformsthataretheproductsofwell-knownstandardisedprocesses,plant-basedprocessesstartbyextractingthe

relevantproteinsandotheringredientsfromtherawmaterial.Thisprocessiscommonlyreferredtoas“extraction”,andresultsinaliquidbase.

Theextractioncanbedonedirectlyataproductionsite.Alternatively,producers

canpurchaseready-madeextractsintheformofconcentrates(compoundsor

syrups),powdersorpastesfromingredientsuppliers.Usinganextractionline

providesanopportunitytotailortheliquidbasetospecificrequirementsinordertocustomiseyourproduct.However,suitableextractioncapabilitymayrequirean

additionalinvestment.

SyrupPowderPaste

17

Theextractionprocesslooksverydifferentdependingonwhattypeofplantrawmaterialisused,butittypicallyinvolves:

?Grindingincludingmixingwithwater

?Enzymatictreatmentforstarch-richrawmaterial,suchasoats

?Separationofinsolublesolids

?Heattreatment

Theprocessandparametersusedintheextractionwillhaveanimpactonthe

productcomposition,taste,mouthfeelandevenfunctionalityofproteinsand

carbohydrates.Itisacrucialstepforthefinalproductqualityandcanimpacttherestoftheproductionline.Figure5showsanexamplefromoat-basedproduction.

Dry

handling

Grindingormixing

Fermentedproducts

SeparationStorage

Hydrolysation

Deactivation&cooling

Cheese

alternatives

Plant-basedcreams

Preparedfoods

Beverages

Frozendesserts

Figure5Oatextractionprocess

MoreinformationabouttheextractionprocessofoatbasecanbefoundintheTetraPakwhitepaper

“Oat-basedbeverages”

.

18

Productformulation

Theformulationstepiscommonlycarriedoutusingamixerwherethedifferent

ingredients(powdersorliquids)areincorporatedintheplant-basedordairyliquid.

Thestartingpointforformulationinadairylineistypicallypasteurisedmilkwherethefatlevelhasalreadybeenadjusted(standardised)totherequiredlevel.The

powdervolumesaddedareoftenlowandconsistofpowdersthatareeasytomixanddissolve(sugarormilkpowderconcentrates),meaningthatmanyproducersdothemixingcold.Aftermixing,theproductisstillalow-viscosityliquid.

Forplant-basedproductstheingredientlistcouldbelongerandtheamountofingredientshigherthanfordairyproducts.Someingredientsmayrequirewarmmixing,andtheadditionofoilandcertainstabiliserstypicallyneedhigh-shearmixingtocreateamixthatishomogeneousandlump-free.Forthisreason,

ahigh-shearmixerisrecommendedaswellasamixingstationthatincludesheatingfunctionality.

Inthecaseoftheproductformulationstep,itisthereforeoftentheplant-based

productsthathavethehighestrequirementsontheequipmentused.Amixing

stationwithahigh-shearmixerandheatingfunctionalityisbeneficialalsofordairyproducts,evenifitisnotstrictlynecessary.

19

Heattreatment

Theformulatedliquidbase,whetherdairyorplant-based,isheat-treatedbeforefermentation,accomplishingthreemajorchanges:

?Iteliminatespathogenicbacteriathatwouldbeabletogrowandmultiplyinthe

finalproduct.Thisisalegalrequirement.Theheattreatmentwillalsoreducethe

overallmicrobialload,whichgivesthestarterculturecompetition-freeconditionstofermenttheproductwhenitisadded.

?Itdenaturesproteins,whichisofgreatimportancetodairyproducts,asthiswillsignificantlyimprovethetextureandstabilityofthefinalproduct.Infact,the

proteindenaturationiswhatdeterminestheheattreatmentprogramfortheseproducts.

Forplant-basedproductsdenaturationofproteinsdoesn’talwayshaveadirectconnectiontothefinalproductquality.Notonlyistheregenerallylessproteininplant-basedproducts,buttheirfunctionalitydiffersfromthoseofdairy.

Inaddition,theplant-basedliquidisoftenalreadyheatedtohightemperaturesintheextractionprocess,meaningthattheheattreatmentbeforefermentationisjustpartofthetotalheatloadappliedtotheproductbeforefermentation,andproteindenaturationmaythereforealreadyhavetakenplace.

?Itactivatesthefunctionalityofdifferentstabilisersandthickeners,forinstance

starch.Asmentionedearlier,stabilisersandthickenersarenotstrictlynecessaryinallfermentedproducts,butareoftenaddedasawaytoimprovethefinalproductqualityintermsoftextureandstability.

Heattreatmentofdairyproductsisoftendonebyheatingthemilkto60-65°C,atwhichtemperaturetheproductishomogenisedatapressureof200barorhigher.Sometimesthehomogenisationstepisprecededbypassingthemilkthrougha

deaeratortoreducetheamountofairintheproduct.Theproductisthenheatedfurtherto90-95°Candheld