A flavoring material applied to a backing for an aerosol-generating or nicotine-containing product

Abstract

There is provided a flavour material for use in an aerosol-generating article, wherein the flavourant is releasable from the flavour material upon heating the flavour material. The flavour material comprises a polysaccharide matrix structure comprising gellan gum and emulsifier; a flavourant formulation dispersed within the polysaccharide matrix structure, wherein the flavourant formulation is at least partly trapped within the polysaccharide matrix structure and releasable from the polysaccharide matrix structure upon heating of the flavour material; and a carrier thread material, wherein the polysaccharide matrix structure and the flavourant formulation are supported by the carrier thread material. Also provided is an aerosol-generating article comprising one such flavour material.

Description

[0001]SUPPORTED^FLAVOUR^MATERIAL FOR^AN^AEROSOL-GENERATING^ARTICLE^OR^NICOTINE^CONTAINING^PRODUCT The^present^disclosure relates^to a^flavour^material for^use^in^an^aerosol-generating^article.^^Further,^the^present^disclosure^relates^to^aerosol-generating^articles^comprising^one^such^flavour^ material.^^ Aerosol-generating^articles^in^which^an^aerosol-generating^substrate,^such^as^for^example^a^tobacco-containing^substrate or^a^non-tobacco,^nicotine-containing^substrate,^is^heated^rather^than^combusted,^are^known^in^the^art.^^Typically,^in^such^heated^smoking^articles^an^aerosol^is^ generated^by^the^transfer^of^heat^from^a^heat^source^to^a^physically^separate^aerosol-generating^ substrate^or^material,^which^may^be^located^in^contact^with,^within,^around,^or^downstream^of^the^ heat^source.^^During^use^of^the^aerosol-generating^article,^volatile^compounds^are^released^from^ the^aerosol-generating^substrate^by^heat^transfer^from^the^heat^source^and^are^entrained^in^air^ drawn^through^the^aerosol-generating^article.^^As^the^released^compounds^cool,^they^condense^ to^form^an^aerosol.^^ Several^aerosol-generating^devices^for^consuming^aerosol-generating^articles have^been^disclosed^in^the^art.^^Such^devices^include,^for^example,^electrically^heated^aerosol-generating^ devices^in^which^an^aerosol^is^generated^by^the^transfer^of^heat^from^one^or^more^electrical^heater^elements^of^ the^aerosol-generating^device^ to^ the^ aerosol-generating^ substrate^of^ an aerosol-generating^ article.^ ^ For^ example,^ electrically^ heated^ aerosol-generating^ devices^ have^ been^proposed^that^comprise^an^internal^heater^blade^which^is^adapted^to^be^inserted^into^the^aerosol-generating^ substrate.^ ^ As^ an^ alternative,^ inductively^ heatable^ aerosol-generating^ articles^comprising^ an^ aerosol-generating^ substrate^ and^ a^ susceptor^ arranged^ within^ the^ aerosol-generating^substrate^have^been^proposed^by^WO^2015 / 176898.^^ It^ has^ been^ proposed^ to^ include^ in^ aerosol-generating^ articles^ a^ source^ of^ flavour^ in^addition^to^the^aerosol-generating^substrate.^^In^effect,^this^practice^was^relatively^common^with^conventional^ filter^ cigarettes,^ and^ a^ number^ of^ solutions^ have^ been^ described^ in^ the^ art^ for^providing^a^flavourant^at^a^location^in^a^mouthpiece^filter^or^in^the^rod^of^tobacco^cut^filler.^^ However,^given^how^the^aerosol^is^generated^and^delivered^to^the^consumer in^aerosol-generating^articles,^ensuring a^consistent^flavour^delivery^during^use may^be^difficult,^and^so^a^consumer may^perceive^fluctuations^or^a^decrease^in^flavour^ intensity^over^time.^^Additionally,^even^prior^to^the^aerosol-generating^articles^being^used,^some^flavour^species^may^be^lost^during^certain^production^steps or^during^transportation^and^storage^of^the^aerosol-generating^articles.^^It^has^previously^been^proposed^to^reduce^the^loss^of^volatile^flavourants^from^smoking^conventional^ filter^ cigarettes during^ storage^ through^ the^ encapsulation^ of^ the^ flavourant,^ for^example^ in^ the^ form^ of^ a^ capsule^ or^ microcapsule containing^ a^ flavour^ formulation.^ The^encapsulated^flavour species can^be^released^prior^to^or^during^smoking^of^the^filter^cigarette^by^breaking^ open^ the^ encapsulating^ structure,^ for^ example^ by^ manually^ crushing^ the^ structure.^^However,^the^encapsulated^flavourant^is^typically^released^from^the^encapsulating^structure^in^a^ single^burst,^and^so^one^such^solution^might^fail^to^provide^a^consistently^intense^flavour^delivery^during^use of^the^article.^^Therefore,^a^need^is^felt^to^provide^flavour^materials,^as^well^as aerosol-generating^articles^containing^ flavour^materials, that^ are^ associated^with^ an^ enhanced^ flavour^perception^ for^ the^consumer,^particularly^towards^the^end^of^the^use^cycle^of^the^aerosol-generating^article.^^ The^present^disclosure^relates^to^a^flavour^material for^use^in^an^aerosol-generating^article,^wherein^a^flavourant^formulation^is^releasable^from^the^flavour^material upon^heating^the^flavour^material.^ ^ The^ flavour^material may^ comprise^a^matrix^ structure^ and^ a^ flavourant^ formulation^dispersed^within^the^matrix^structure.^^The^flavourant formulation^is^at^least^partly^trapped^within^the^matrix^ structure^ and^ is^ releasable^ from^ the^ matrix^ structure^ upon^ heating^ of^ the^ flavour^material.^^The^matrix^structure^may^be^a^polysaccharide^matrix^structure.^^The^flavour^materialmay^comprise^a^carrier^thread^material,^ the^polysaccharide^matrix^structure^and^the^flavourant^formulation^being supported^by^the^carrier^thread material.^^According^to^an^aspect^of^the^present^invention,^there^is^provided^a^flavour^material^^for^use^ in^an^aerosol-generating^ article;^ the^ flavour^material comprising:^ a^polysaccharide^matrix^structure;^and^a^flavourant^formulation^dispersed^within^the^polysaccharide^matrix^structure.^^The^ flavourant^formulation^is^at^least^partly^trapped^within^the^polysaccharide^matrix^structure^and^is^releasable^ from^ the^polysaccharide^matrix^structure^upon^heating^of^ the^ flavour^material.^ ^The^flavour^material comprises^a^carrier^thread material,^the^polysaccharide^matrix^structure^and^the^flavourant^formulation^being supported^by^the^carrier^thread material.^^As^ used^ herein,^ the^ term^ “thread material” denotes^ an elongate^ filamentous^material^having^a^length^substantially^greater^than^an^equivalent diameter^thereof.^^The^term^“equivalent^diameter^of^a thread”^is^used^herein^to^denote^the^diameter^of^the^circle^ which^ has^ the^ same^ transverse^ cross-sectional^ area^ as^ the^ thread.^ ^ In^ general,^ the^transverse^cross-section^of^the^thread^may^have^any^shape,^although^a^circular^or^quasi-circularshape,^ such^as^an^oval shape^or^elliptical shape^ is^preferred.^ ^For^a^ thread^having^a^ circular^transverse^ cross-section,^ the^ equivalent^ diameter^ is^ the^ diameter^ of^ the^ cross-section^ of^ the^thread.^^ For^example,^the^carrier^thread^material^may^be^a yarn^comprising^cellulosic^fibres.^In^the^manufacture^of^a^thread^material,^typically,^natural^plant^fibres^are^cleaned,^carded^to^disentangle^and^align^the^fibres,^and^optionally^combed,^before^being^spun^into^yarn.^The^cellulosic^fibres of^the^carrier^thread^material^may^include^fibres^derived^from^one^or^more^plants,^such^as^cottonfibres,^flax fibres,^hemp fibres,^bamboo fibres,^sisal fibres,^ramie fibres,^coir fibres,^kenaf fibres,^abaca fibres and^ jute fibres.^Alternatively,^ the^carrier^ thread^material^may^ include^ regenerated^cellulose^ fibres.^Regenerated^cellulose^ fibres^are^ formed^ from^cellulose^ that^ is^extracted^ from^wood^ pulp,^ which^ is^ then^ chemically^ dissolved^ and^ extruded^ as^ a^ filament.^ The^ regenerated^cellulose^may^be^formed^from^cellulose^from^any^suitable^wood^pulp^feedstock,^for^instance^but^not^limited^to^wood^pulp^derived^from^bamboo,^eucalyptus,^beech,^birch, spruce,^pine,^maple^and^aspen.^Preferably,^the^cellulosic^fibres^are^cotton^fibres,^such^that^the^carrier^thread^material^is^a^ cotton^yarn.^^Alternatively,^the^cellulosic^fibres^may^be^regenerated^cellulose^fibres. As^used^herein^with^ reference^ to^ the^ invention,^ the^ term^ “aerosol-generating^article”^ is^used^to^describe^an^article^comprising^an^aerosol-generating^substrate^that^is^heated^to^generate^ an^inhalable^aerosol^for^delivery^to^a^user. As^used^herein^with^reference^to^the^invention,^the^term^“aerosol-generating^substrate”^is^ used^to^describe^a^substrate^comprising^aerosol-generating^material^that^is^capable^of^releasing^ upon^heating^volatile^compounds^that^can^generate^an^aerosol. As^used^herein^with^reference^to^the^invention,^the^term^“aerosol”^is^used^to^describe^a^dispersion^ of^ solid^ particles,^ or^ liquid^ droplets,^ or^ a^ combination^ of^ solid^ particles^ and^ liquid^droplets,^in^a^gas.^^The^aerosol^may^be^visible^or^invisible.^^The^aerosol^may^include^vapours^of^substances^ that^are^ordinarily^ liquid^or^solid^at^ room^ temperature^as^well^as^solid^particles,^or^liquid^droplets,^or^a^combination^of^solid^particles^and^liquid^droplets. As^used^herein^with^ reference^ to^ the^ invention,^ the^term^“aerosol-generating^device”^ is^used^ to^describe^a^device^ that^ interacts^with^ the^aerosol-generating^ substrate^of^ the^aerosol-generating^article^to^generate^an^aerosol.^^ Aerosol-generating^articles^according^to^the^invention^have^a^proximal^end^through^which,^ in^use,^an^aerosol^exits^the^aerosol-generating^article^for^delivery^to^a^user.^^The^proximal^end^of^ the^aerosol-generating^article^may^also^be^referred^to^as^the^downstream^end^or^mouth^end^of^the^aerosol-generating^article.^^In^use,^a^user^draws^directly or^indirectly^on^the^proximal^end^of^the^aerosol-generating^article^in^order^to^inhale^an^aerosol^generated^by^the^aerosol-generating^ article. Aerosol-generating^articles^according^to^the^invention^have^a^distal^end.^^The^distal^end^is^ opposite^the^proximal^end.^^The^distal^end^of^the^aerosol-generating^article^may^also^be^referred^ to^as^the^upstream^end^of^the^aerosol-generating^article. Components^of^aerosol-generating^articles^according^to^the^invention^may^be^described^ as^being^upstream^or^downstream^of^one^another^based^on^their^relative^positions^between^the^ proximal^end^of^the^aerosol-generating^article^and^the^distal^end^of^the^aerosol-generating^article. As^used^herein^with^reference^to^the^invention,^the^term^“longitudinal”^is^used^to^describe^the^ direction^ between^ the^ upstream^ end^ and^ the^ downstream^ end^ of^ the^ aerosol-generating^article.^^During^use,^air^is^drawn^through^the^aerosol-generating^article^in the^longitudinal^direction.As^used^herein^with^reference^to^the^invention,^the^term^“length”^is^used^to^describe^the^ maximum^dimension^of^the^aerosol-generating^article^or^a^component^of^the^aerosol-generating^ article^in^the^longitudinal^direction. As^used^herein^with^reference^to^the^invention,^the^term^“transverse”^is^used^to^describe^ the^direction^perpendicular^to^the^longitudinal^direction.^^Unless^otherwise^stated,^references^to^the^ “cross-section”^of^ the^aerosol-generating^article^or^a^ component^of^ the^aerosol-generating^article^refer^to^the^transverse^cross-section. As^used^herein^with^reference^to^the^invention,^the^term^"hollow^tubular^element"^is^used^ to^denote^a^generally^cylindrical^element^having^a^lumen^along^a^longitudinal^axis^thereof.^^The^ tubular^portion^may^have^a^substantially^circular,^oval^or^elliptical^cross-section.^^The^lumen^may^ have^a^substantially^circular,^oval^or^elliptical^cross-section.^^In^particular,^the^term^"hollow^tubular^element"^ is^ used^ to^ denote^ an^ element defining^ at^ least^ one^ airflow^ conduit^ establishing^ an^uninterrupted^fluid^communication^between^an^upstream^end^of^the^hollow^tubular^element^and^a^ downstream^end^of^the^tubular^element.^^ The^ inclusion^ of^ a^ carrier^ thread^material^ in^ flavour^materials^ in^ accordance^ with^ the^present^invention^has^been^found^to^enhance the^structural^strength^of^the^flavour^materials^by^virtue^of^ the^carrier^ thread^material^supporting^and^holding^ in^place^ the^polysaccharide^matrix^trapping^the^flavour^formulation.^^By^selecting^and^adjusting^certain^properties^of^the^carrier^thread^ material^(for^example,^its^thickness)^one^may^obtain^a^flavour^material^that^is^especially^resistant^ to^wear^and^tear^and^that^has^particularly^good^mechanical^properties.^^ Compared^with^flavour^materials^having^a^comparable^composition^and^matrix^structure,^but^ lacking^the^support^of^ the^carrier^ thread material,^ flavour^materials^ in^accordance^with^the^present^invention^have^thus^been^found^to^be^easier^to^handle^and^may^more^conveniently^stored,^ for^example,^in^bobbin^form.^^This^advantageously^facilitates^their^incorporation^into^an^aerosol-generating^article,^ particularly^within^ the^ framework^of^ a^high-speed^automated^manufacturing^process.^^ Flavour^materials^in^accordance^with^the^present^invention^also^have^the^advantage^that^the^ polysaccharide^ matrix^ structure^ and^ the^ flavourant^ formulation^ trapped^ therein^ may^ be^deposited^onto^the^carrier^thread material to^form^a^flavour^material^ that^ is,^ in^effect,^ in^threadform^and^that^can,^as^such,^be^cut^into^pieces^having^a^predetermined^average^size^(for^example,^ a^predetermined^cut^length).^^This^makes^it^easy^to^combine^a^flavour^material^in^accordance^with^ the^present^invention^with^an^aerosol-generating^substrate^in^certain^aerosol-generating^articles,^ as^will^be^described^in^more^detail^below.^^ In^some^embodiments,^the^carrier^thread material^may^alternatively^comprise^a^plurality^of^pieces^cut^from^a^thread material,^the^pieces^having^a^predetermined^average^size^(for^example,^a^predetermined cut^length).^^In^flavour^materials^in^accordance^with^the^present^invention,^the^polysaccharide^matrix^structure^trapping^the^flavourant^formulation^may^be^formed in^situ on^the^carrier^thread material.^^If^this^in^situ formation^step^follows^a^manufacturing^process^from^which^the^carrier^threadmaterial^is^obtained,^ the^ in^situ formation^step^may^even^be^performed^at^a^ later^date^or^at^a^different^location.^^ In^general,^it^has^been^recognised^that^use^of^a^flavour^material^in^an^aerosol-generating^ article,^wherein^an^aerosol-generating^substrate^is^meant^to^be^heated^to^generate^the^aerosol,^presents^ different^ challenges^ and^ poses^ different^ constraints,^ compared^ with^ conditions^encountered^ in^ the^ past^ with^ conventional^ cigarettes,^ wherein^ a^ substrate^ is^ combusted^ to^generate^a^smoke.^ ^The^ inventors^have^ found^ that^by^adjusting^ the^ relative^proportions^of^ the^various^ingredients^in^the^formulation^or by^altering^the^composition^of^the^matrix^– for^example,^by^selecting^certain^combinations^of^polysaccharides to^form^the^matrix^– or^by^doing^both,^it^may^advantageously^be^possible^to^finely^tailor^certain^characteristics^of^the^flavour^material^to^specific^needs^associated^with^use^ in^an^aerosol-generating^article.^ ^For^example,^ the^ flavour^ release^profile may^be^adjusted,^such^as^to^have^the^flavour^released^in^more^successive^“waves”^during^use.^^As^a^result,^the^consumer^may^perceive^flavour^notes^as^more^intense^or^lingering^for^longer^ during^use.^^Thus,^flavour^materials^in^accordance^with^the^present^invention^may^offer^a^wider^ breadth^of^flavour^profiles^that^were^not^accessible^with^the^known^flavour^materials.^^ When^a^flavour^material^ in^accordance^with^the^ invention^is^ incorporated^in^an^aerosol-generating^article,^such^as^for^example^a^heat-not-burn^article^configured^to^generate^an^aerosol^ upon^heating^a^tobacco-containing^aerosol-generating^substrate,^puff-by-puff^flavour^release^has^ been^found^to^be^generally^more^efficient.^^ Because^ the^ flavourant^ formulation^ is^at^ least^partly^ trapped^within^the^matrix^until^ it^ is^released^upon^heating,^ flavour^materials^ in^accordance^with^ the^present^ invention^have^been^found^ to^ exhibit^ increased^ stability.^ ^ For^ example,^ a^ significant^ reduction^ in^ losses^ of^ flavour^species^ during^ storage,^ transportation,^ and^ so^ forth,^ has^ been^ observed,^ even^ under^ stress^conditions.^^Coupled^with^the^enhancement^in^flavour^release,^this^makes^for^a^particularly^efficient^ use^of^flavourants^and^other^ingredients^of^the^flavour^formulation.^^ Preferably,^the^polysaccharide^matrix^structure^comprises^gellan^gum^and^an^emulsifier.^^The^ term^ “gellan^ gum”^ is^ used^ to^ identify^ a^ water-soluble^ anionic^ polysaccharide,^ which^ isproduced^ by^ the^ bacterium^ Sphingomonas^ elodea.^ ^ The^ repeating^ unit^ of^ the^ polymer^ is^ a^tetrasaccharide,^which^ consists^of^ two^ residues^of^D-glucose^ and^one^of^ each^ residues^ of^ L-rhamnose^and^D-glucuronic^acid.^^Gellan^gum^has^been^approved^for^food,^non-food,^cosmetic^and^ pharmaceutical^ uses^ by^authorities^ in^many^ jurisdictions,^ such^ as^ Japan,^USA,^Canada,^China,^South^Korea^and^the^EU.^ Two^forms^of^gellan^gum^are^known^– namely,^high^acyl^gellan^gum^and^low^acyl^gellan^gum^– which^differ^by^way^of^the^degree / percent^of^substitution^by^O-acyl^groups.^^In^flavour^materials^in^accordance^with^the^present^invention,^the^gellan^gum^is^preferably^low^acyl^gellan^gum.^^This^is^a^gellan^gum^that^is^partly^deacylated^or^fully^deacylated.^^ Its^most^common^ form^ is^ the^ fully^deacylated^one,^with^no^detectable^acyl^groups,^which^ is^also^called^deacetylated^gellan^gum.^^ Use^ of^ low^ acyl^ gellan^gum^ to^ form^ the^polysaccharide^matrix^ of^ a^ flavour^material^ in^accordance^with^ the^present^ invention^ is^preferred^because^ low^acyl^gellan^gum^ is^capable^of^forming^gels^at^very^low^concentrations.^^Additionally,^the^texture^of^gellan gum^based^gels^varies^with^the^acyl^content,^ low^acyl^gellan^gum^typically^forming^firmer,^ less^elastic^and^more^brittle^gels^compared^with^high^acyl^gellan^gum.^^ In^embodiments^wherein^the^polysaccharide^matrix^structure^comprises^gellan^gum^and^ an^emulsifier,^a^flavour^material^may^advantageously^be^provided^wherein^a^substantial^fraction^ of^the^flavourant^formulation^is^effectively^trapped^within^the^polysaccharide^matrix^structure.^^This^ is^beneficial^in^that^it^improves^the^stability^of^the^flavour^material.^^Further,^as^it^will^be^discussed^in^more^detail^ below,^ it^ has^an^ impact^on^how^ flavour^ species^are^ released^upon^heating^ the^flavour^material,^and^so^it^may^help^tune^a^flavourant^release^profile^during^use.^^ Additionally,^ from^ a^manufacturing^ viewpoint,^ a^ stable^ polysaccharide^matrix^ structure^comprising gellan^gum^and^an^emulsifier can^be^formed^by^supplying^heat^to^the^starting^reagents^without^requiring^the^use^of^cross-linking^agents.^^In^fact,^by^kneading^and^emulsifying^the^flavour^ formulation^and^gellan^gum^in^a^heated^aqueous^bath,^the^polysaccharide-coated^flavourant^can^be^brought^to^an^emulsified^state^which^is^then^substantially preserved^after^drying^and^cooling.^^Advantageously,^this^allows^for^a^significant^amount^of^flavourant^to^be^provided^in^an^immobilised^ state^within^the^polysaccharide^matrix,^and^so^a^flavour^material^with^a^high^flavourant^content^ may^be^provided.^^ Preferably,^the^emulsifier^is^lecithin.^^Use^of^lecithin^as^the^emulsifier^is^advantageous^in^that^ it^ is^ commonly^ available^ and^ generally^ recognised^ as^ being^non-toxic.^ ^ Like^gellan^gum,^lecithin^is^commonly^used^in^the^food^industry^as^an^additive,^and^has^been^approved^for^such^ use^by^both^the^USA^Food^and^Drug^Administration^and^the^EU^authorities.^^As^such,^the^pairing^ of^gellan^gum^and^lecithin^is^especially^adapted^to^be^included^in^a^flavour^material^destined^for^ human^use.^^ Preferably,^where^the^polysaccharide^matrix^comprises^gellan^gum^and^an^emulsifier,^the^ gellan^gum^makes^up^from^5^percent^by^weight^to^99.9^percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^ More^preferably,^ the^gellan^gum^makes^up^at^ least^7 percent^by^weight^of^ the^ flavour^material on^a^dry^weight^basis,^even^more^preferably^at^least^10 percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^The^gellan^gum^preferably^makes^up^for^up^to^80 percent^by^weight^of^the^flavour^materialon^a^dry^weight^basis,^more^preferably^up^to^60 percent^by^weight^of^the^flavour^material on^a^dry^weight^basis,^even^more^preferably^up^to^40 percent^by^weight^of^the^flavour^material on^a^dry^weight^basis,^particularly^preferably^up^to^30 percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^ In^some^embodiments,^the^gellan^gum^makes^up^from^5 percent^by^weight^to^80 percent^by^weight^of^the^flavour^material on^a^dry^weight^basis,^preferably^from^5 percent^by^weight^to^60percent^by^weight^of^the^flavour^material on^a^dry^weight^basis,^more^preferably^from^5 percent^by^ weight^ to^ 40 percent^ by^ weight^ of^ the^ flavour^material on^ a^ dry^ weight^ basis,^ even^more^preferably^from^5 percent^by^weight^to^30 percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^ In^other^embodiments,^the^gellan^gum^makes^up^from^10 percent^by^weight^to^80 percent^by^weight^of^the^flavour^material on^a^dry^weight^basis,^preferably^from^10 percent^by^weight^to^60 percent^by^weight^of^the^flavour^material on^a^dry^weight^basis,^more^preferably^from^10 percent^by^ weight^ to^ 40 percent^ by^ weight^ of^ the^ flavour^material on^ a^ dry^ weight^ basis,^ even^more^preferably^from^10 percent^by^weight^ to^30 percent^by^weight^of^ the^flavour^material on^a^dry^weight^basis.^^ The^emulsifier^may^make^up^from^0.01^percent^by^weight^to 2^percent^by^weight^of^ the^flavour^material on^a^dry^weight^basis.^^Preferably,^the^emulsifier^makes^up^from^0.02^percent^by^weight^to 2^percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^More^preferably,^the^emulsifier^makes^up^from^0.05^percent^by^weight^to 2^percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^Even^more^preferably,^the^emulsifier^makes^up^from^0.1^percent^by^weight^to2^percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^In^preferred^embodiments,^emulsifier^is^lecithin^and^makes^up^from^0.01^percent^by^weight^to^2^percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^Preferably,^lecithin^makes^up^ from^0.02^percent^by^weight^ to^2^percent^by^weight^of^ the^ flavour^material on^a^dry^weight^basis.^^More^preferably,^lecithin^makes^up^from^0.05^percent^by^weight^to^2^percent^by^weight^of^the^ flavour^material on^a^dry^weight^basis.^ ^Even^more^preferably,^ lecithin^makes^up^ from^0.1^percent^by^weight^to^2^percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^In^certain^embodiments,^the^polysaccharide^matrix^structure^comprises^gellan^gum^as^the^ sole^polysaccharide.^^ In^ other^ embodiments,^ the^ polysaccharide^ matrix^ structure comprises^ gellan^ gum^ in^combination^with^at^ least^a^ further^polysaccharide^selected^ from^ the^group^consisting^of^guar,^tamarind^ gum,^ sodium^ alginate,^ xanthan^ gum,^ sodium^ carboxymethyl^ cellulose,^ and^hydroxypropyl^methyl^cellulose.^^ Flavour^materials^according^to^the^invention^wherein^the^polysaccharide^matrix^structure comprises^gellan^gum^in^combination^with^one^or^more^of^the^polysaccharides^listed^above^have^been^ found^ to^ provide^ different^ flavourant^ release^ profiles^ upon^ heating.^ ^ For^ example,^ in^embodiments^wherein^the^polysaccharide^matrix^structure comprises^gellan^gum^in^combination^with^another^one^of^the^polysaccharides^listed^above,^a^flavourant^release^profile^characterised^by^two^distinct^peaks^at^ two^different^temperatures^has^been^observed.^^Without^wishing^to^be^bound^by^theory,^it^is^hypothesised^that^this^is^due^to^a^different^strength^of^interaction^between^ the^flavourant^and^each^polysaccharide^in^the^matrix^structure,^and^may^also^have^to^do^with^each^ polysaccharide^undergoing^thermal^decomposition^at^slightly^different^temperatures.^^ Because^different^combinations^of^polysaccharides^in^the^matrix^structure^will^generally^lead^ to^ slightly^ different^ flavourant^ release^ profiles^ when^ the^ flavour^ material^ is^ heated,^embodiments^wherein^gellan^gum^ is^combined^with^one^or^more^of^ the^other^polysaccharides^listed^above^may^advantageously^be^used^to^fine-tune^the^flavourant^release during^use^of^an^aerosol-generating^article^containing^the^flavour^material.^^Additionally,^different^flavour^materials,^each^ containing^ a^ polysaccharide^ matrix^ structure^ comprising^ a^ different^ combination^ of^polysaccharides,^may^ be^used^ in^ combination^ in^ a^ single^ aerosol-generating^article^ to^ further^adjust^and^control^flavourant^delivery^during^a^whole^use^cycle^of^the^aerosol-generating^article.^^For^ example,^ incorporating^ in^ a^ single^ aerosol-generating^ article^ different^ flavour^ materials^according^to^the^invention,^wherein^the^different^flavour^materials^are^adapted^to^release^most^of^ the^flavourant^at^different^temperature^or^at^different^times^during^the^use^cycle^may^help^maintain^ an^overall^flavour^delivery^substantially^consistent^throughout.^^ In^embodiments^of^the^flavour^material^wherein^the^matrix^structure^comprises^gellan^gum^in^combination^with^at^least^one of^the^additional^polysaccharides^listed^above,^the^at^least^one^additional^polysaccharide^may^make^up^at^least^0.01^percent^by^weight^of^the^flavourant^delivery^ material^on^a^dry^weight^basis.^^Preferably,^the^at^least^one^additional^polysaccharide^makes^up^at^ least^0.1^percent^by^weight^of^ the^ flavourant^delivery^material^on^a^dry^weight^basis.^ ^More^preferably,^the^at^least^one^additional^polysaccharide^makes^up^at^least^1.0^percent^by^weight^of^the^flavourant^delivery^material^on^a^dry^weight^basis.^ ^Even^more^preferably,^ the^at^ least^one^additional^ polysaccharide^makes^ up^ at^ least^ 2.0^ percent^ by^ weight^ of^ the^ flavourant^ delivery^material^on^a^dry^weight^basis.^^In^particularly^preferred^embodiments,^the^at^least^one^additional^ polysaccharide^makes^up^at^least^5^percent^by^weight^of^the^flavourant^delivery^material^on^a^dry^ weight^basis.^^ In^embodiments^of^the^flavour^material^wherein^the^matrix^structure^comprises^gellan^gum^in^combination^with^at^least^one of^the^additional^polysaccharides^listed^above,^the^at^least^one^additional^polysaccharide^may^make^up^80^percent^by^weight^or^ less^of^the^flavourant^delivery^material^on^a^dry^weight^basis.^^Preferably,^the^at^least^one^additional^polysaccharide^makes^up^35^percent^by^weight^ or^ less^of^ the^ flavourant^delivery^material^ on^a^dry^weight^ basis.^ ^More^preferably,^the^at^least^one^additional^polysaccharide^makes^up^25^percent^by^weight^or^less^of^the^flavourant^delivery^material^on^a^dry^weight^basis.^ ^Even^more^preferably,^ the^at^ least^one^additional^ polysaccharide^ makes^ up^ 15^ percent^ by^ weight^ or^ less^ of^ the^ flavourant^ delivery^material^on^a^dry^weight^basis.^^In^ some^ embodiments,^ the^ at^ least^ one^ additional^ polysaccharide^makes^up^ from^1.0^percent^to^35^percent^by^weight^or^less^of^the^flavourant^delivery^material^on^a^dry^weight^basis,^ preferably^from^2.0^percent^to^35^percent^by^weight^or^less^of^the^flavourant^delivery^material^on^a^ dry^weight^ basis,^more^preferably^ from^ 5.0^ percent^ to^ 35^ percent^ by^weight^ or^ less^of^ the^flavourant^delivery^material^on^a^dry^weight^basis.^^ In^ other^ embodiments,^ the^ at^ least^ one^ additional^ polysaccharide^makes^ up^ from^ 1.0^percent^to^25^percent^by^weight^or^less^of^the^flavourant^delivery^material^on^a^dry^weight^basis,^ preferably^from^2.0^percent^to^25^percent^by^weight^or^less^of^the^flavourant^delivery^material^on^a^ dry^weight^ basis,^more^preferably^ from^ 5.0^ percent^ to^ 25^ percent^ by^weight^ or^ less^of^ the^flavourant^delivery^material^on^a^dry^weight^basis.^^ In^ further^embodiments,^ the^at^ least^ one^additional^ polysaccharide^makes^up^ from^1.0^percent^to^15^percent^by^weight^or^less^of^the^flavourant^delivery^material^on^a^dry^weight^basis,^ preferably^from^2.0^percent^to^15^percent^by^weight^or^less^of^the^flavourant^delivery^material^on^a^ dry^weight^ basis,^more^preferably^ from^ 5.0^ percent^ to^ 15^ percent^ by^weight^ or^ less^of^ the^flavourant^delivery^material^on^a^dry^weight^basis.^^ The^flavour^material^may^comprise^at^least^0.01^percent^by^weight^of^a^flavourant^on^a^dry^weight^ basis.^ ^ Preferably,^ the^ flavour^ material^ comprises^ at^ least^ 1^ percent^ by^ weight^ of^ a^flavourant^ on^ a^dry^weight^ basis.^ ^More^ preferably,^ the^ flavour^material^ comprises^ at^ least^ 5percent^by^weight^of^a^flavourant^on^a^dry^weight^basis.^^Even^more^preferably,^the^flavour^material^comprises^at^least^10 percent^by^weight^of^a^flavourant^on^a^dry^weight^basis.^^In^certain^embodiments,^the^flavour^material^comprises^at^least^20 percent^by^weight^of^a^flavourant^on^a^dry^weight^basis,^preferably^at^least^25 percent^by^weight^of^a^flavourant^on^a^dry^weight^basis,^more^preferably^at^least^30 percent^by^weight^of^a^flavourant^on^a^dry^weight^basis.^^The^flavour^material^may^up^to^90 percent^by^weight^of^a^flavourant^on^a^dry^weight^basis.^^Preferably,^the^flavour^material^may^up^to^85 percent^by^weight^of^a^flavourant^on^a^dry^weight^basis.^^More^preferably,^the^flavour^material^may^up^to^80 percent^by^weight^of^a^flavourant^on^a^dry^weight^basis.^^Even^more^preferably,^the^flavour^material^may^up^to^75 percent^by^weight^of^a^flavourant^on^a^dry^weight^basis.^^ In^ certain^ preferred^ embodiments,^ the^ flavour^material^ comprises^ from^ 20 percent^ by^weight^to^80^percent^by^weight^of^a^flavourant^on^a^dry^weight^basis,^preferably^from^25 percent^by^weight^to^80^percent^by^weight^of^a^flavourant^on^a^dry^weight^basis,^more^preferably^from^30 percent^by^weight^to^80^percent^by^weight^of^a^flavourant^on^a^dry^weight^basis.^^ In^other^preferred^embodiments,^the^flavour^material^comprises^from^20 percent^by^weight^to^75^percent^by^weight^of^a^flavourant^on^a^dry^weight^basis,^preferably^from^25 percent^by^weight^to^75^percent^by^weight^of^a^flavourant^on^a^dry^weight^basis,^more^preferably^from^30 percent^by^weight^to^75^percent^by^weight^of^a^flavourant^on^a^dry^weight^basis.^^Suitable^ flavourants^ for^ inclusion^ in^ the^ flavour^ formulation^ of^ a^ flavour^ material^ in^accordance^with^the^present^invention^include,^but^are^not^limited^to:^^ Suitable^ flavourants^ for^ inclusion^ in^ the^ flavour^ formulation^ of^ a^ flavour^ material^ in^accordance^with^ the^present^ invention^ include,^ but^are^not^ limited^ to,^menthol,^ limonene,^and^eugenol.^^ Menthol^is^a^monoterpenoid,^which^may^be^made^synthetically^or^obtained^from^the^oils^of^ peppermint^or^other^mints.^^It^imparts^minty,^cool^flavour^notes.^^ Limonene^is^a^cyclic^monoterpene,^and^is^typically^found^in^the^oil^of^citrus^fruit^peels.^^It^is^also^a^component^of^ the^aromatic^resins^of^numerous^coniferous^and^broadleaved^trees.^^ It^imparts^citrusy^flavour^notes.^^ Eugenol^is^an^allyl^chain-substituted^guaiacol,^and^is^commonly^found^in^the^essential^oils^ of^clove,^nutmeg,^cinnamon,^basil^and^bay^leaf.^^It^imparts^spicy,^clove-like^flavour^notes.^^ The^ inventors^have^ found^ that^menthol^ and^ limonene^can^be^ fairly^ easily^ trapped^and^immobilised^ within^ the^ polysaccharide^ matrix,^ and^ so^ flavour^ materials^ containing^ a^ flavour^formulation^containing^menthol,^limonene^or^mixtures^thereof^exhibit^very^good^stability.^^^ In^preferred^embodiments,^the^flavourant^formulation^comprises^menthol.^^ The^flavour^material^may^comprise^at^least^0.01^percent^by^weight^of^a^menthol^on^a^dry^ weight^basis.^^Preferably,^the^flavour^material^comprises^at^least^1^percent^by^weight^of^a^menthol^on^a^dry^weight^basis.^^More^preferably,^the^flavour^material^comprises^at^least^5 percent^by^weight^of^a^menthol^on^a^dry^weight^basis.^^Even^more^preferably,^the^flavour^material^comprises^at^least^10 percent^by^weight^of^a^menthol^on^a^dry^weight^basis.^^In^certain^embodiments,^the^flavour^material^comprises^at^least^20 percent^by^weight^of^a^menthol^on^a^dry^weight^basis,^preferably^at^ least^25 percent^by^weight^of^a^menthol^on^a^dry^weight^basis,^more^preferably^at^least^30 percent^by^weight^of^a^menthol^on^a^dry^weight^basis.^^The^flavour^material^may^up^to^90 percent^by^weight^of^a^menthol^on^a^dry^weight^basis.^^Preferably,^ the^ flavour^material^may^up^ to^85 percent^by^weight^of^a^menthol^on^a^dry^weight^basis.^^More^preferably,^the^flavour^material^may^up^to^80 percent^by^weight^of^a^menthol^on^a^dry^weight^basis.^ ^Even^more^preferably,^ the^flavour^material^may^up^to^75 percent^by^weight^of^a^menthol^on^a^dry^weight^basis.^^ In^ certain^ preferred^ embodiments,^ the^ flavour^material^ comprises^ from^ 20 percent^ by^weight^to^80^percent^by^weight^of^a^menthol^on^a^dry^weight^basis,^preferably^from^25 percent^by^weight^ to^80^percent^by^weight^ of^a^menthol^ on^a^dry^weight^basis,^more^preferably^ from^30percent^by^weight^to^80^percent^by^weight^of^a^menthol^on^a^dry^weight^basis.^^ In^other^preferred^embodiments,^the^flavour^material^comprises^from^20 percent^by^weight^to^75^percent^by^weight^of^a^menthol^on^a^dry^weight^basis,^preferably^from^25 percent^by^weight^to^75^percent^by^weight^of^a^menthol^on^a^dry^weight^basis,^more^preferably^from^30 percent^by^weight^to^75^percent^by^weight^of^a^menthol^on^a^dry^weight^basis.^^ In^some^embodiments,^the^flavour^material^further^comprises^a^polyol^having^the^formula^ CnH2n+2On.^^ The^term^“polyol”^is^used^herein^to^describe^an^organic^compound^comprising^two^or^more^ hydroxyl^groups.^^Polyols^containing^two,^three,^and^four^hydroxyl^groups^may^also^be^referred^to^ as^diols,^triols,^and^tetrols,^respectively.^^ Preferred^ polyols^ for^ inclusion^ in^ a^ flavour^ material^ in^ accordance^ with^ the^ present^invention^include^glycerol,^sorbitol,^xylitol,^mannitol,^and^erythritol.^^ The^incorporation^of^a^polyol^in^the^flavour^material^has^a^beneficial^effect^on^its^pliability.^^ This^may^make^the^flavour^material^easier^to^handle^and^given^a^predetermined^form,^which^may^ facilitate^its^incorporation^into^an^aerosol-generating^article.^^ Preferably,^in^embodiments^where^the^flavour^material^comprises^a^polyol^as^described^ above,^the^polyol^makes^up^from^0.01^percent^by^weight^to^20^percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^More^preferably,^the^polyol^makes^up^from^0.01^percent^by^weight^to^15 percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^Even^more^preferably,^the^polyol^makes^up^from^0.01^percent^by^weight^to^10 percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^ In^some^embodiments,^the^polysaccharide^matrix^may^comprise^a^salt^of^calcium^or^a^salt^of^magnesium^ or^ both,^ such^ as^ one^or^more^ of^ calcium^ lactate,^magnesium^ lactate,^ calcium^carbonate,^magnesium^ carbonate,^ calcium^ acetate^ and^magnesium^ acetate.^ ^ Preferably,^ the^polysaccharide^matrix^may^ comprise^ one^ or^more^ of^ calcium^ lactate,^ calcium^ carbonate^ andcalcium^acetate.^Most^preferably,^the^polysaccharide^matrix^may^comprise^calcium^lactate. The^ inclusion^ of^ a^ calcium^ or^ magnesium^ salt,^ especially^ calcium^ lactate,^ calcium^carbonate^or^calcium^lactate^within^the^polysaccharide^matrix^has^been^found^to^improve^adhesion^ of^the^polysaccharide^matrix^to^the^carrier^thread^material. In^ embodiments^ where^ the^ flavour^ material^ comprises^ a^ salt^ of^ calcium^ or^ a^ salt^ of^magnesium^or^both,^the^salt^or^salts^make^up^from^0.01^percent^by^weight^to^10^percent^by^weight^on^a^dry^weight^basis.^ ^Preferably,^ the^salt^or^salts^make^up^from^0.01^percent^by^weight^to^5^percent^by^weight^on^a^dry^weight^basis.^^ A^flavour^material^in^accordance^with^the^present^invention^may^generally^comprise^water.^^This^ is^because^ the^ flavour^material^will^generally^ be^manufactured^by^ combining^ the^ various^compounds^described^above^in^an^aqueous^bath.^^After^drying,^the^water^content^will^be^reduced,^ but^may^generally^be^non-null.^^ Thus,^a^flavour^material^in^accordance^with^the^present^invention^may^comprise^from^0.01^ percent^by^weight^to^10^percent^by^weight^of^water,^preferably^from^0.01^percent^by^weight^to^8^percent^by^weight^of^water,^more^preferably^from^0.01^percent^by^weight to^6^percent^by^weight^of^water,^even^more^preferably^from^0.01^percent^by^weight^to^4^percent^by^weight^of^water.^^ In^some^embodiments,^the^flavour^material^comprises^from^0.5^percent^by^weight^to^10^ percent^by^weight^of^water,^preferably^from^0.01^percent^by^weight^to^8^percent^by^weight^of^water,^ more^preferably^from^0.5^percent^by^weight^to^6^percent^by^weight^of^water,^even^more^preferably^ from^0.5^percent^by^weight^to^4^percent^by^weight^of^water.^^ In^other^embodiments,^ the^flavour^material^comprises^from^1.0^percent^by^weight^to^10^percent^by^weight^of^water,^preferably^from^1.0^percent^by^weight^to^8^percent^by^weight^of^water,^ more^preferably^from^1.0^percent^by^weight^to^6^percent^by^weight^of^water,^even^more^preferably^ from^1.0^percent^by^weight^to^4^percent^by^weight^of^water.^ In^further^embodiments,^the^flavour^material^comprises^from^1.5^percent^by^weight^to^10^ percent^by^weight^of^water,^preferably^from^1.5^percent^by^weight^to^8^percent^by^weight^of^water,^ more^preferably^from^1.5^percent^by^weight^to^6^percent^by^weight^of^water,^even^more^preferably^ from^1.5^percent^by^weight^to^4^percent^by^weight^of^water.^^ The^ carrier^ thread^ material^ may^ have^ an^ equivalent diameter^ of^ at^ least^ about^ 0.05^millimetre^and^less^than^or^equal^to^about^1^millimetre,^such^as^at^least^about^0.1^millimetre^and^ less^than^or^equal^to^about^0.8^millimetre,^such^as^at^least^about^0.12^millimetre^and^less^than^or^ equal^to^about^0.4^millimetre. The^carrier^thread^material^may^have^any^suitable^length^for^inclusion^in a^flavour^material^for^ use^ in^an^aerosol-generating^article. For^example,^ the^carrier^ thread^material^may^have^a^length^of^at^least^about^0.5^millimetres,^such^as^at^least^about^1^millimetre.^ The^term^“breaking^force”^ is^used^throughout^the^specification^to^ indicate^a^measure^of^the^force^required^to^stretch^a^thread^material^until^it^breaks.^It^is^expressed^in^Newtons (N).^The^term^“elongation^at^break”^is^used^throughout^the^specification^to^refer^to^the^percentage^increase^ in^the^length^of^the^thread^at^the^point^at^which^it^breaks.^ISO^2062^may^be^used^to^determine^the^breaking^ force^and^elongation^at^break^of a thread^material.^ In^ this^ test,^ the^ test^ specimen^ is^clamped^on^either^end^ in^ stationary^ jaws^and^ is^pulled^at^a^ constant^ rate^of^extension^until^ it^breaks.^ The^carrier^thread^material^may^have^a^breaking^force^of^about^1^N^to^about^20^N,^such^as^about 2^N^to^about^15^N,^such^as^about^3^N^to^about^10^N,^such^as^about^4^N^to^about^8^N.The^carrier^thread^material^may^have^an^elongation^at^break^of^between^about^2%^and^ about^20%,^such^as^between^about^3%^and^about^15%,^such^as^between^about^4%^and^about^ 8%.^ As^mentioned^previously,^in^some^preferred^embodiments,^the^carrier^thread^material^may^ be^a^cotton^yarn. In^ certain^ embodiments,^ carbon^ particles may^be^ dispersed^within^ the^ polysaccharide^matrix^structure.^^The^carbon^particles^may^be^at^least^partly^trapped^within^the^polysaccharide^matrix^ structure.^ ^ Preferably,^ the^ flavour^material^ comprises^ greater^ than^ 0.1^ weight^ percent^carbon^particles,^ the^ carbon^particles^ having^a^ volume^mean^particle^ size^ of^ greater^ than^10^micrometres.^^ The^inclusion^of^carbon^based^material^– such^as^graphite,^expanded^graphite,^graphene,^etc.^ – in^ the^ flavour^material has^been^ found^ to^enhance^ flavour^ release,^ particularly^ at^ lower^temperatures,^with^respect^to^flavour^materials^having^comparable^composition^and^structure,^but^lacking^ the^carbon^enriched polysaccharide^matrix^structure.^ ^Without^wishing^ to^be^bound^by^theory,^ this^ is^ hypothesised^ to^ relate^ to^ an^ enhancement^ of^ the^ thermal^ conductivity^ of^ thepolysaccharide^matrix^structure,^which^may^cause^the^flavourant^formulation^to^be^more^promptly^released^ from^ the^polysaccharide^matrix^ structure^as^a^ certain^ threshold^ temperature^may^be^reached^more^quickly.^^ The^improvement^in^flavour^release^is^thought^to^be^linked^to^a^more^even^temperature^ distribution^throughout^the^flavour^material^during^use.^^With^a^greater^proportion^of^the^flavour^material^ reaching^ a^ sufficiently^ high^ temperature^ to^ release^ flavour^ species^ from^ the^ matrix^structure,^a^higher^usage^efficiency^of^the^flavourant^formulation^is^made^possible.^^^ The^improved^release^of^flavour^species^afforded^by^embodiments^of^the^flavour^material^ in^accordance^with^the^present^invention^including^carbon^particles^as^described^above^may^also^ allow^a^heater^configured^to^supply^heat^to^an^aerosol-generating^article^incorporating^the^flavour^ delivery^material^to^operate^at^a^lower^temperature^and^thus^require^less^power.^^ By^adjusting^the^amount^and^size^of^the^carbon^particles,^it^may^be^possible^to^control^and^fine-tune^ the^ flavour^ release^ enhancement.^ ^ For^ example,^ a^ relatively^ narrow^ particle^ size^distribution^ may^ provide^ a^ flavour^ material^ that^ is^ more^ homogenous^ in^ terms^ of^ thermal^conductivity.^ ^ This^may^mean^ that,^ during^ use,^ temperature^ gradients^ in^ the^ flavour^ delivery^material^provided^ in^different^portions^of^an^aerosol-generating^article^that^are^exposed^to^ the^same^heating^profile^are^minimised.^^ Preferably,^ the^carbon^particles^consist^of^one^or^more^of:^graphite^particles,^expanded^graphite^particles^and^graphene^particles.^^In^a^preferred^embodiment,^the^carbon^particles^consist^ of^one^or^both^of^expanded^graphite^particles^and^graphene^particles.^^ Advantageously,^particles^such^as^those^listed^above,^particularly^graphite^and^expanded^graphite,^may^have^a^high^thermal^conductivity^and^a^ low^density,^and^so^they^may^be^able^to^substantially^ improve^ the^ thermal^ conductivity^ of^ the^ flavour^ material^ without^ significantly^increasing^the^density^of^the^flavour^material.^ This may^be^advantageous^in^that^an^increase^in^density^may^ increase^ the^weight,^and^ therefore^ the^ transport^costs,^ for^a^given^volume^of^ the^flavour^material^itself.^^Equally,^an^increase^in^density^may^potentially^have^a^proportional^impact^ on^transport^costs^when^the^flavour^material^is^incorporated^into^an^aerosol-generating^article.^^ Additionally,^ particles^ such^ as^ those^ listed^ above^ have^ the^ benefit^ that^ they^ may^ be^inductively^heated,^and^so^heat^may^be^supplied^directly^within^a^flavour^material^in^accordance^with^ the^ present^ invention^ when^ the^ flavour^ material^ is^ exposed^ to^ an^ electromagnetic^ field^generated^by^an^induction^coil.^^^^ Preferably,^the^carbon^particles^have^a^volume^mean^particle^size^from^30^micrometres^to^ 150^micrometres.^^ As^used^herein,^the^term^“volume^mean^particle^size”^may^refer^to^a^mean^calculated^using^ the^equation^below,^where^d[4,3]^is^the^volume^mean^particle^size^and^d^is^the^particle^size. ^^ ^^^^ ^ ^^ ^^ ^^In^other^words,^the^volume^mean^particle^size^may^refer^to^a^mean^calculated^by^dividing^ the^sum^of^the^particle^sizes^to^the^fourth^power^by^the^sum^of^the^particle^sizes^to^the^third^power. Surprisingly,^ the^ inventors^have^ found^ these^ relatively^ small^particle^ size^ ranges^ to^be^particularly^effective^at^ increasing^ the^ thermal^conductivity^of the flavour^material.^ ^ In^addition,^these^ relatively^ small^ particle^ sizes^ may^ advantageously^ result^ in^ a^ more^ homogeneous^distribution^of^thermal^conductivity.^^ The^carbon^particles^may^have^a^particle^size^distribution^having^a^D10^particle^size,^a^D50^particle^size,^and^a^D90^particle^size.^^In^such^a particle^size^distribution,^10%^of^the^particles^have^a^particle^size^which^is^less^than^or^equal^to^the^D10^particle^size^and^90%^of^the^particles^ have^a^particle^size^which^is^less^than^or^equal^to^the^D90^particle^size.^^The^D50^particle^size^is^ the^median^particle^size^so^50%^of^the^particles^have^a^particle^size^which^is^less^than^or^equal^to^ the^D50^particle^size.^^ The^D90^particle^size^may^be^less^than^or^equal^to^50,^40,^30,^25,^20,^15,^10,^8,^5,^or^3^ times^the^D10^particle^size.^The^D90^particle^size^may^be^greater^than^or^equal^to^2,^3,^5^or^8^ times^the^D10^particle^size.^ The^D90^particle^size^may^be^between^3^and^50,^3^and^40,^3^and^30,^3^and^25,^3^and^20,^ 3^and^15,^3^and^10,^3^and^8,^3^and^5,^5^and^50,^5^and^40,^5^and^30,^5^and^25,^5^and^20,^5^and^ 15,^5^and^10,^5^and^8,^8^and^50,^8^and^40,^8^and^30,^8^and^25,^8^and^20,^8^and^15,^8^and^10,^10^ and^50,^10^and^40,^10^and^30,^10^and^25,^10^and^20,^10^and^15,^15^and^50,^15^and^40,^15^and^ 30,^15^and^25,^15^and^20^times^the^D10^particle^size. Preferred^particle^size^distributions^may^have^a^D90^particle^size^between^3^and^25,^or^3^and^15,^times^the^D10^particle^size. Particularly^preferred^particle^size^distributions^may^have^a^D90^particle^size^between^5^and^20,^or^5^and^10,^times^the^D10^particle^size. In^certain^preferred^embodiments,^in^a^flavour^material according^to^the^present^invention^the^carbon^particles^have^a^particle^size^distribution^with^a^D90^particle^size^and^a^D10^particles^ size,^and^the^D90^particle^size^is^no^more^than^25^or^15^times^the^D10^particle^size.^^ A^compromise^must^be^made^in^relation^to^the^particle^size^distribution.^^A^tighter^particle^ size^distribution^may^advantageously^provide^a^more^uniform^thermal^conductivity^throughout^the^ flavour^material.^^This^is^because^there^will^be^less^variation^in^particle^size^in^different^locations^ in^the^flavour^material.^^This^may^advantageously^allow^for^more^efficient^usage^of^the^flavourant^formulation^ throughout^ the^ flavour^material.^ ^ However,^ a^ tighter^ particle^ size^distribution^may^disadvantageously^be^more^difficult^and^expensive^to^achieve.^^The^inventors^have^found^that^the^ particle^size^distributions^described^above^may^provide^an^optimal^compromise^between^these^ two^factors.^^ Desired^D10^and^D90^particle^sizes^may^be^obtained^by^sieving.^^Sieving^may^therefore^ be^used^to^obtain^a^narrow^particle^size^distribution^where^desired.^^ The^D10^particle^size^of^the^carbon^particles^may^be^greater^than^or^equal^to^1,^2,^3,^5,^10,^20,^30,^35,^50,^75,^100,^150,^200,^250,^500,^or^900^microns. Each^of^the^carbon^particles^may^have^a^particle^size^of^greater^than^or^equal^to^1,^2,^3,^5,^10,^20,^30,^35,^50,^75,^100,^150,^200,^ 250,^500,^or^900^microns. The^D10^particle^size^of^the^carbon^particles^may^be^less^than^or^equal^to^1000,^900,^500,^200,^100,^150,^100,^75,^50,^35,^30,^20,^10,^5,^3^or^2^microns. Each^of^the^carbon^particles^may^have^a^particle^size^of^less^than^or^equal^to^1000,^900,^500,^200,^100,^150,^100,^75,^50,^35,^30,^ 20,^10,^5,^3^or^2^microns. The^D90^particle^size^of^the^carbon^particles^may^be^less^than^or^equal^to^1000,^900,^500,^200,^100,^150,^100,^75,^50,^35,^30,^20,^10,^5,^3^or^2^microns. Each^of^the^carbon^particles^may^have^a^particle^size^of^less^than^or^equal^to^1000,^900,^500,^200,^100,^150,^100,^75,^50,^35,^30,^ 20,^10,^5,^3^or^2^microns. The^D90^particle^size^of^the^carbon^particles^may^be^greater^than^or^equal^to^1,^2,^3,^5,^10,^20,^30,^35,^50,^75,^100,^150,^200,^250,^500,^or^900^microns. Each^of^the^carbon^particles^may^have^a^particle^size^of^greater^than^or^equal^to^1,^2,^3,^5,^10,^20,^30,^35,^50,^75,^100,^150,^200,^ 250,^500,^or^900^microns. One^or^both^of^a^D50^particle^size^and^a^volume^mean^particle^size^of^the^carbon^particles^may^be greater^than^or^equal^to^1,^2,^3,^5,^10,^20,^30,^35,^50,^75,^100,^150,^200,^250,^500,^or^900^microns. One^or^both^of^a^D50^particle^size^and^a^volume^mean^particle^size^of^the^carbon^particles^may^be less^than^or^equal^to^1000,^900,^500,^200,^100,^150,^100,^75,^50,^35,^30,^20,^10,^5,^3^or^2^microns. One^or^both^of^a^D50^particle^size^and^a^volume^mean^particle^size^of^the^carbon^particles^ may^be^between^1^and^1000,^preferably^between^10^and^200,^more^preferably^between^30^and^150,^or^even^more^preferably^between^50^and^75^microns. Alternatively,^or^in^addition,^each^of^the^carbon^particles^may^have^a^particle^size^of^between^1^and^1000,^preferably^between^10^and^ 200,^more^preferably^between^30^and^150,^or^even^more^preferably^between^50^and^75^microns. Surprisingly,^ the^ inventors^have^ found^ these^ relatively^ small^particle^ size^ ranges^ to^be^particularly^effective^at^increasing^the^thermal^conductivity^of^a^flavour^material^in^accordance^with^ the^present^invention.^^In^addition,^these^relatively^small^particle^sizes^may^advantageously^result^ in^a^more^homogeneous^flavour^material^in^terms^of^thermal^conductivity The^carbon^particles^may^have^a^volume^mean^particle^size^of^greater^than^or^equal^to^1,^ 2,^3,^5,^10,^20,^30,^35,^50,^75,^100,^150,^200,^250,^500,^or^900^microns.^ It^may^be^particularly^preferable^that^the^volume^mean^particle^size^of^the^carbon^particles^ is^greater^than^10^microns. The^carbon^particles^may^have^a^volume^mean^particle^size^of^less^than^or^equal^to^1000,^ 900,^500,^200,^100,^150,^100,^75,^50,^35,^30,^20,^10,^5,^3^or^2^microns.^ The^carbon^particles^may^have^a^volume^mean^particle^size^of^between^1^and^1000,^10^and^200,^30^and^150,^or^50^and^75^microns. These^volume^mean^particle^size^ranges^may^be^particularly^preferable^where^the flavour^material^comprises,^or^is^in^the^form^of,^a^sheet.The^carbon^particles^may^have^a^volume^mean^particle^size^at^least^2,^3,^5,^8,^10,^15,^or^ 20^times^the^number^mean^particle^size. It^may^be^particularly^preferable^that^the^thermally^conductive^particles^are,^or^comprise,^ graphite^particles.^ The^graphite^particles^may^have^a^particle^ size^distribution^with^a^D10^particle^ size^of^between^5^and^20,^for^example^10^and^14,^microns,^for^example^around^12^microns.^^The^graphite^particles^may^have^a^particle^ size^distribution^with^a^D50^particle^ size of^between^25^and^45^microns,^ for^ example^ around^ 35^ microns. The^ graphite^ particles^ may^ have^ a^ particle^ size^distribution^ with^ a^ D90^ particle^ size^ of^ between^ 45^ and^ 75^microns,^ for^ example^ around^ 55^microns.^^Advantageously,^such^particles^are^commercially^available^and^have^been^found^by^the^ inventors^to^provide^a^significant^increase^in^the^thermal^conductivity^of^flavour^materials. It^may^be^particularly^preferable^that^the^thermally^conductive^particles^are,^or^comprise,^ expanded^graphite^particles.^ The^expanded^graphite^particles^may^have^a^particle^size^distribution^with^a^D10^particle^ size^of^between^5^and^20,^for^example^9^and^12,^microns,^for^example^around^10.5^microns.^^The^expanded^ graphite^ particles^may^ have^ a^ particle^ size^ distribution^ with^ a^ D50^ particle^ size^ of^between^15^and^25^microns,^for^example^around^20^microns. The^expanded^graphite^particles^may^have^a^particle^size^distribution^with^a^D90^particle^size^of^between^46^and^66^microns,^for^example^around^56^microns.^ ^Advantageously,^ such^particles^are^ commercially^ available^and^have^been^found^by^the^inventors^to^provide^a^significant^increase^in^the^thermal^conductivity^of^ flavour^materials.^^The^expanded^graphite^particles^may^also^advantageously^reduce^the^overall^ density^of^the^flavour^material. Each^of^the^carbon^particles^may^have^three^mutually^perpendicular^dimensions.^^A^largest^ dimension^of^these^three^dimensions^may^be^no^more^than^10,^8,^5,^3,^or^2^times^larger^than^a^ smallest^dimension^of^these^three^dimensions.^^A^largest^dimension^of^these^three^dimensions^ being^no^more^than^10,^8,^5,^3,^or^2^times^larger^than^a^second^largest^dimension^of^these^three^dimensions.^^Each^of^ these^three^dimensions^may^be^substantially^equal.^ ^Each^of^ the^carbon^particles^may^be^substantially^spherical. The^carbon^particles^may^comprise^at^least^10,^20,^50,^100,^200,^500,^or^1000^particles.^^ In^a^flavour^material^in^accordance^with^the^present^invention,^the^carbon^particles^make^up from^0.01^percent^by^weight^to^10^percent^by^weight^of^the^flavour^material on^a^dry^weight^basis.^^^ In^a^flavour^material^in^accordance^with^the^present^invention,^the^polysaccharide^matrix^ structure^and^the^flavourant^formulation^form^a^layer^on^the^carrier^thread^material.^^The^layer^may^have^a^thickness^of^at^least^5 micrometres.^^In^a^flavour^material^in^accordance^with^the^present^invention^the^polysaccharide^matrix^structure^and^ the^ flavourant^ formulation^ form^a^ layer^on^ the^ carrier^ thread^material,^ the^ layer^preferably^ having^a^ thickness^ of^ at^ least^ 10^micrometres,^ the^ layer^more^preferably^having^ a^thickness^of^at^least^15^micrometres,^the^layer^even^more^preferably^having^a^thickness^of^at^least^ 20^micrometres.^^ In^a^flavour^material^in^accordance^with^the^present^invention^the^polysaccharide^matrix^structure^and^ the^ flavourant^ formulation^ form^a^ layer^on^ the^ carrier^ thread^material,^ the^ layer^preferably^having^a^thickness^of^less^than^or^equal^to^150^micrometres,^the^layer^more^preferably^having^a^ thickness^of^ less^ than^or^ equal^ to^125^micrometres,^ the^ layer^even^more^preferably^having^a^thickness^of^less^than^or^equal^to^100^micrometres.^^ In^some^embodiments,^the^polysaccharide^matrix^structure^and^the^flavourant^formulation^form^ a^ layer^ on^ the^ carrier^ thread material,^ the^ layer^ preferably^ having^ a^ thickness^ from^ 10^micrometres^ to^ 150^ micrometres,^ the^ layer^ more^ preferably^ having^ a^ thickness^ from^ 10^micrometres^ to^ 125^micrometres,^ the^ layer^even^more^ preferably^ having^a^ thickness^ form^ 10^micrometres^to^100^micrometres.^^ In^other^embodiments,^the^polysaccharide^matrix^structure^and^the^flavourant^formulation^form^ a^ layer^ on^ the^ carrier^ thread^material,^ the^ layer^ preferably^ having^ a^ thickness^ from^ 15^micrometres^ to^ 150^ micrometres,^ the^ layer^ more^ preferably^ having^ a^ thickness^ from^ 15^micrometres^ to^ 125^micrometres,^ the^ layer^even^more^ preferably^ having^a^ thickness^ form^ 15^micrometres^to^100^micrometres.^^ In^further^embodiments,^the^polysaccharide^matrix^structure^and^the^flavourant^formulation^form^ a^ layer^ on^ the^ carrier^ thread^material,^ the^ layer^ preferably^ having^ a^ thickness^ from^ 20^micrometres^ to^ 150^ micrometres,^ the^ layer^ more^ preferably^ having^ a^ thickness^ from^ 20^micrometres^ to^ 125^micrometres,^ the^ layer^even^more^ preferably^ having^a^ thickness^ form^ 20^micrometres^to^100^micrometres.^^ Flavour^materials^in^accordance^with^the^present^invention^can^be^prepared^by^different^ routes.^^The^present^disclosure^also^relates^to^a^method^of^manufacturing^a^flavour^material^in^accordance^with^ the^present^ invention,^which^may^comprise^a^ first^ step^of^heating^water^ to^a^temperature^ of^ at^ least^ 50^ degrees^ Celsius.^ ^ The^ method^ may^ comprise^ a^ second^ step^ of^dispersing^gellan^gum^ into^ the^ heated^water^ to^ form^a^gellan^gum^aqueous^ dispersion.^ ^ The^method^may^comprise^a^third^step^of^heating^the^gellan^gum^aqueous^dispersion^to^a^temperature^ of^at^least^80^degrees^Celsius^to^dissolve^the^gellan^gum^and^form^a^gellan^gum^aqueous^solution.^^The^ method^ may^ comprise^ a^ fourth^ step^ of^ cooling^ the^ gellan^ gum^ aqueous^ solution^ to^ a^temperature^from^65^degrees^Celsius^to^75^degrees^Celsius.^^The^method^may^comprise^a^fifth^step^ of^ adding^ to^ the^ cooled^ gellan^ gum^ aqueous^ solution^ a^ flavourant^ formulation^ and^ an^emulsifier^to^form^a^precursor^composition.^^The^method^may^comprise^a^sixth^step^of^applying^ the^precursor^composition^onto^a^carrier^thread^material.^^The^method^may^comprise^a^seventh^ step^of^drying^the^carrier^threadmaterial^with^the^applied^precursor^composition^to^obtain^a^flavour^ delivery^material.^^ According^ to^ another^ aspect^ of^ the^ present^ invention^ there^ is^ provided^ a^ method^ of^manufacturing^a^flavour^material^in^accordance^with^the^present^invention,^the^method^comprising^a^first^step^of^heating^water^to^a^temperature^of^at^ least^50^degrees^Celsius;^a^second^step^of^dispersing^gellan^gum^into^the^heated^water^to^form^a^gellan^gum^aqueous^dispersion;^a^third^step^ of^heating^the^gellan^gum^aqueous^dispersion^to^a^temperature^of^at^least^80^degrees^Celsius^to^dissolve^ the^gellan^gum^and^form^a^gellan^gum^aqueous^solution;^a^ fourth^step^of^cooling^the^gellan^gum^aqueous^solution^to^a^temperature^from^65^degrees^Celsius^to^75^degrees^Celsius;^a^ fifth^step^of^adding^to^the^cooled^gellan^gum^aqueous^solution^a^flavourant^formulation^and^an^emulsifier^ to^form^a^precursor^composition;^a^sixth^step^of^applying^the^precursor^composition^onto^a^carrier^thread material;^and^a^seventh^step^of^drying^the^carrier^thread^material^with^the^applied^precursor^composition^to^obtain^a^flavour^delivery^material.^^ In^some^embodiments,^the^method^further^comprises^a^step^of^adding^to^the^cooled^gellan^gum^aqueous^solution^a^polysaccharide^ selected^ from^ the^group^consisting^of^guar,^ tamarind^gum,^sodium^alginate,^xanthan^gum,^sodium^carboxymethyl^cellulose,^and^hydroxypropyl^methyl^ cellulose.^^This^additional^step^may^be^carried^out^before^the^sixth^step^of^applying^the^precursor^ composition^onto^a^carrier^thread^material.^^ In^some^embodiments,^the^method^further^comprises^a^step^of^adding^to^the^cooled^gellan^gum^aqueous^solution^a^salt^selected^from^the^group^consisting^of calcium^lactate,^magnesium^lactate,^ calcium^ carbonate,^ magnesium^ carbonate,^ calcium^ acetate^ and^magnesium^ acetate.^Preferably,^the^salt^may^comprise^one^or^more^of^calcium^lactate,^calcium^carbonate^and^calcium^ acetate.^Most^preferably,^the^salt^may^be^calcium^lactate.^This^additional^step^may^be^carried^out^ before^the^sixth^step^of^applying^the^precursor^composition^onto^a^carrier^thread^material.^^ Preferably,^in^methods^in^accordance^with^the^present^invention,^the^emulsifier^is^lecithin.^^ In^ certain^embodiments,^ the^ sixth^ step^of^applying^ the^precursor^ composition^onto^ the^carrier^ sheet^ material^ comprises^ dipping^ the^ carrier^ thread^ material^ into^ the^ precursor^composition.^^Preferably,^ the^sixth^step^of^applying^the^precursor^composition^onto^the^carrier^ thread^material^comprises^forming^a^layer^of^the^precursor^composition^over^the^carrier^thread^material^ having^a^thickness^of^at^least^10^micrometres.^^ The^present^disclosure^also^relates^to^an^aerosol-generating^article^comprising^a^flavour^material,^wherein^a^flavourant^formulation^is^releasable^from^the^flavour^material upon^heating^the^flavour^ material.^ ^ The^ flavour^ material may^ comprise^ a^ matrix^ structure^ and^ a^ flavourant^formulation^dispersed^within^ the^matrix^ structure.^ ^The^ flavourant formulation^ is^ at^ least^ partly^trapped^within^the^matrix^structure^and^is^releasable^from^the^matrix^structure^upon^heating^of^the^flavour^material.^ ^The^matrix^structure^may^be^a^polysaccharide^matrix^structure.^ ^The^ flavour^material may^comprise^a^carrier^thread material,^wherein^the^polysaccharide^matrix^structure^and^the^flavourant^formulation^are^supported^by^the^carrier^thread^material According^ to^ a further^ aspect^ of^ the^ present^ invention,^ there^ is^ provided^ an^ aerosol-generating^article^ comprising^a^ flavour^material,^wherein^ the^ flavourant^ is^ releasable^ from^ the^flavour^material upon^ heating^ the^ flavour-delivery^material.^ ^ The flavour^material comprises^ a^polysaccharide^matrix^structure;^and^a^flavourant^formulation^dispersed^within^the^polysaccharide^ matrix^structure.^^The^flavourant^formulation^is^trapped^within^the^polysaccharide^matrix^structure^ and^releasable^from^the^polysaccharide^matrix^structure^upon^heating^of^the^flavour^material.^^The^flavour^material further^comprises^a^carrier^thread^material,^the^polysaccharide^matrix^structure^and^the^flavourant^formulation^being^supported^by^the^carrier^thread^material.^^ As^will^be^apparent^from^the^foregoing^description^of^flavour^materials^in^accordance^with^the^present^invention,^by^incorporating^one^such^flavour^material in^an^aerosol-generating^article^it^ is^advantageously^possible^to^provide^a^new^range^of^aerosol-generating^articles^capable^of^delivering^ flavour^ to^ a^ consumer^ in^ a^ more^ consistent^ and^ controlled^manner.^ ^ Additionally,^because^the^flavourant^formulation^is^at^least^partly^trapped^within^the^matrix^until^it^is^released^ when^heat^is^supplied^to^the^aerosol-generating^article^during^use,^losses^of^flavour^species^during^storage and transportation of^the^aerosol-generating^articles^can^be^greatly^reduced.^^Because^ the^ carrier^ thread material^ provides^ an^ enhanced^ structural support^ for^ the^polysaccharide^matrix^structure^trapping^the^flavourant^formulation,^by^adjusting^the^composition^and^geometry^of^the^carrier^thread^material^manufacturing^of^the^aerosol-generating^article may^be^facilitated.^^ In^ certain^ embodiments,^ the^ aerosol-generating^ article^ comprises^ a^ rod^ of^ aerosol-generating^ substrate;^ a^ downstream^ section^ provided^ downstream^ of^ the^ rod^ of^ aerosol-generating^substrate^and^extending^to^a^mouth^end^of^the^aerosol-generating^article;^optionally^ an^upstream^section^provided^upstream^of^the^rod^of^aerosol-generating^substrate^and^extending^to^a^distal^end^of^the^aerosol-generating^article.^^The^flavour^material is^provided^in^at^least^one^of^the^rod^of^aerosol-generating^substrate;^the^downstream^section;^and^the^optional^upstream^ section.^^As^ described^above,^ the^ carrier^ thread material^may^ in^particular^ be^a yarn^ comprising^cellulosic^fibres,^such^as^a^cotton^yarn.^^In^embodiments wherein^the^flavour^material^comprises^one^such^carrier^thread^material,^the^aerosol-generating^article^may^comprise^a^rod^of^aerosol-generating^ substrate;^ a^ downstream^ section^ provided^ downstream^ of^ the^ rod^ of^ aerosol-generating^substrate^and^extending^to^a^mouth^end^of^the^aerosol-generating^article;^optionally^ an^upstream^section^provided^upstream^of^the^rod^of^aerosol-generating^substrate^and^extending^to^a^distal^end^of^the^aerosol-generating^article;^and^the^flavour^material may^be^provided^in^the^rod^of^aerosol-generating^substrate.^^ Incorporation^of^a^flavour^material in^accordance^with^the^present^invention^in^an^aerosol-generating^article^may^be^carried^out^according^to^one^of^several^routes.^^ For^example,^pieces^of^the^flavour^material may^be^mixed^with^solid^particles^of^an^aerosol-generating^material,^such^as^cut^tobacco,^to^form^the^rod^of^aerosol-generating^substrate^of^an^ aerosol-generating^article.^^ As^an^alternative,^or^additionally,^pieces^of^ the^flavour^material may^be^provided^at^other^locations^within^the^aerosol-generating^article,^such^as^locations^along^the^downstream^section^ of^the^aerosol-generating^article.^^The^downstream^section^of^the^aerosol-generating^article^may^comprise^multiple^components,^and^so^the^flavour^material may^be^incorporated^into^any^one^of^such^components.^^For^example,^the^flavour^material^may^be^incorporated^into^the^aerosol-cooling^ element.^ As^an^alternative,^or^additionally,^pieces^of^the^flavour^material^may^be^provided^at^locations^ along^the^upstream^section^of^the^aerosol-generating^article.^The^upstream^section^of^the^aerosol^ generating^article^may^comprise^a^filter^segment^formed^of^a^fibrous^filtration^material^and^abutting^the^ rod^ of^ aerosol-generating^ substrate^ at^ an^ upstream^ end.^ The^ flavour^ material^ may^ be^incorporated^into^the^filter^segment. Preferably,^ the^ flavour^material^ is^ positioned^ in^ a^ component^ of^ the^ aerosol-generating^article^that^is^proximate^or^adjacent^to^the^heat^source, such that heat is received by the flavourmaterial to^activate^flavour^release.This^list^of^possible^arrangements^is^not^meant^to^be^exhaustive,^and^it^will^be^apparent^that^different^ placements^ of^ a^ flavour^ material in^ an^ aerosol-generating^ article^ may^ be^ possible,^provided^ that^during^use^of^ the^aerosol-generating^article^ the^ flavour^material is^ supplied^with^enough^heat^to^release^the^flavour^formulation^from^the^polysaccharide^matrix.^^ An^aerosol-generating^article^containing^a^flavour^material in^accordance^with^the^present^invention^may^be^used^in^combination^with^an^aerosol-generating^device,^such^as^a^hand-held^ electrical^heater^configured^to^supply^heat^in^a^controlled^manner^to^the^aerosol-generating^article.^^ This^is^so,^by^heating^the^aerosol-generating^substrate^and^the^flavour^material,^a^flavour-enriched aerosol^can^be^delivered^to^a^consumer.^^ As^such,^aerosol-generating^articles^according^to^the^invention^find^particular^application^in^ aerosol-generating^ systems^ comprising^ an^ aerosol-generating^ device^ having^ a heating^chamber^into^which^the^aerosol-generating^article^is^received^such^that^heat^can^be^supplied^to^the^ aerosol-generating^ substrate.^ ^ This^ may^ be^ achieved^ by^ providing^ one^ or^ more^ heating^elements^arranged^about^the^periphery^of^the^heating^chamber,^the^one^or^more^heating^elements^being^heated^ resistively^or^ inductively.^ ^ Alternatively,^ this^may^ also^be^achieved^by^way^of^ a^resistively^heated^blade-shaped^component^of^the^aerosol-generating^device,^which^is^inserted^into^ the^ aerosol-generating^ substrate^ when^ the^ aerosol-generating^ article^ is^ inserted^ into^ the^heating^chamber.^^ According^ to^ yet^ another^alternative,^ a^ susceptor^ element^may^ be^provided^within^ the^aerosol-generating^ substrate,^ and^ the^ aerosol-generating^ device^ may^ have^ an^ inductor^ for^producing^an^alternating^or^fluctuating^electromagnetic^field.^ When^the^aerosol-generating^article^engages^with^the^aerosol-generating^device,^the^fluctuating^electromagnetic^field^produced^by^the^inductor^induces^a^current^in^the^susceptor element,^causing^the^susceptor^element^to^heat^up.^The^electrically-operated^aerosol-generating^device^may^be^capable^of^generating^a^fluctuating^ electromagnetic^field^having^a^magnetic^field^strength^(H-field^strength)^of^between^1^and^5^kilo^ amperes^per^metre^(kA^m),^preferably^between^2^and^3^kA / m,^for^example^about^2.5^kA / m.^ The^invention^is^defined^in^the^claims.^ However,^below^there^is^provided^a^non-exhaustive^list^ of^ non-limiting examples.^ Any^ one^ or^ more^ of^ the^ features^ of^ these^ examples^ may^ be^combined^with^any^one^or^more features of^another example,^embodiment,^or^aspect^described^herein. Example^ Ex1:^ A^ flavour^ material for^ use^ in^ an^ aerosol-generating^ article, wherein^ the^flavourant^ is^releasable^from^the^flavour^material^upon^heating^the^flavour^material;^ the^flavour^material comprising:^a^polysaccharide^matrix^structure comprising^gellan^gum^and^emulsifier;^a^flavourant^ formulation^ dispersed^ within^ the^ polysaccharide^ matrix^ structure,^ wherein^ the^flavourant^ formulation^ is^at^ least^ partly^ trapped^within^ the^polysaccharide^matrix^ structure^and^releasable^from^the^polysaccharide^matrix^structure^upon^heating^of^the^flavour^material;^and a^carrier^thread^material,^wherein^the^polysaccharide^matrix^structure^and^the^flavourant^formulation^are^supported^by^the^carrier^thread material.^^Example^Ex2:^A^ flavour^material^according^ to^Example^Ex1,^wherein^ the^polysaccharide^matrix^structure^comprises^gellan^gum^as^the^sole^polysaccharide^or^gellan^gum^in^combination^ with^at^least^a^further^polysaccharide^selected^from^the^group^consisting^of^guar,^tamarind^gum,^sodium^ alginate,^ xanthan^ gum,^ sodium carboxymethyl^ cellulose,^ and^ hydroxypropyl^ methyl^cellulose.^^ Example^Ex3:^A^flavour^material^according^to^Example^Ex1^or^Ex2,^wherein^the^gellan^gum^makes^up from^5^percent^by^weight^to^99.9^percent^by^weight^of^ the^flavour^material^on^a^dry^weight^basis.^^Example^Ex4:^A^ flavour^material^according^ to^any^one^of^Examples^Ex^1^ to^Ex3,^ further^comprising^a^polyol^having^the^formula^CnH2n+2On.^^ Example^Ex5:^A^flavour^material^according^to^Example^Ex4,^wherein^the^polyol^is^selected^ from^the^group^consisting^of^glycerol,^sorbitol,^xylitol,^mannitol,^and^erythritol.^^ Example^Ex6:^A^ flavour^material^ according^ to^ Example^Ex4^ or^ Ex5,^wherein^ the^polyol^accounts^from^0.01^percent^by^weight^to^20^percent^by^weight^of^ the^flavour^material^on^a^dry^weight^basis.^^ Example^Ex7:^A^flavour^material^according^to any^one^of^the^preceding^Examples,^wherein^the^carrier^thread^material^comprises^cellulosic^fibres. Example^Ex8: A^flavour^material^according^to^Example^Ex7,^wherein^the^cellulosic^fibres^comprise^fibres^derived^from^one^or^more^plants,^such^as^cotton^fibres,^flax^fibres,^hemp^fibres,^bamboo^fibres,^sisal^fibres,^ramie^fibres,^coir^fibres,^kenaf^fibres,^abaca^fibres^and^jute^fibres, or^regenerated^cellulose^fibres. Example^Ex9:^A^flavour^material^according^to^any^one^of^the^preceding^Examples,^wherein^ the^carrier^thread^material^is^a^cotton^yarn.^^ Example^ Ex10:^ A^ flavour^ material^ according^ to^ any^ one^ of^ the^ preceding^ Examples^comprising^from^0.01^percent^by^weight^to^80^percent^by^weight^of^menthol.^^ Example^Ex11:^A^flavour^material^according^to^any^one^of^the^preceding^Examples,^wherein^the^polysaccharide^matrix^ structure^and^ the^ flavourant^ formulation^ form^a^ layer^on^ the^ carrier^thread^material,^the^layer^having^a^thickness^of^at^least^10^micrometres.^^ Example^Ex12:^A^ flavour^material^ according^ to^Example^Ex11,^wherein^ the^ layer^has^a^thickness^of^less^than^150^micrometres.^^ Example^Ex^13:^A^flavour^material^according^to^any^one^of^the^preceding^Examples,^wherein^ the^polysaccharide^matrix^may^comprise^a^salt^of^calcium^or^a^salt^of^magnesium^or^both,^such^ as^one^or^more^of^calcium^lactate,^magnesium^lactate,^calcium^carbonate,^magnesium^carbonate,^ calcium^acetate^and^magnesium^acetate.^^ Example^Ex14:^A^flavour^material^according^to^Example^Ex13,^wherein^the^polysaccharide^ matrix^comprises^calcium^lactate. Example^Ex15:^A^flavour^material^according^to^Example^Ex13,^or^Example^Ex14^wherein^ the^flavour^material^comprises^from^0.01^percent^by^weight^to^10^percent^by^weight^of^the^salt^or^ salts,^on^a^dry^weight^basis.^^ Example^Ex16:^A^flavour^material^according^to^any^one^of^Examples^Ex13^to^Ex15,^wherein^ flavour^material^comprises^from^0.01^percent^by^weight^to^5^percent^by^weight^of^the^salt^or^salts,^ on^a^dry^weight^basis.^^ Example^Ex17:^A^method^of^preparing^a^flavour^material^for^use^in^an^aerosol-generating^article, the^method^comprising:^heating^water^to^a^temperature^of^at^ least^50^degrees^Celsius;^dispersing^gellan^gum^into^the^heated^water^to^form^a^gellan^gum^aqueous^dispersion;^heating^ the^gellan^gum^aqueous^dispersion^to^a^temperature^of^at^least^80^degrees^Celsius^to^dissolve^ the^gellan^gum^and^form^a^gellan^gum^aqueous^solution;^cooling^the^gellan^gum^aqueous^solution^ to^a^temperature^from^65^degrees^Celsius^to^75^degrees^Celsius;^adding^to^the^cooled^gellan^gum^aqueous^ solution^ a^ flavourant^ formulation^and^ an^emulsifier^ to^ form^a^ precursor^ composition;^applying^ the^ precursor^ composition^ onto^ a^ carrier^ thread^ material;^ drying^ the^ carrier^ thread^material^with^the^applied^precursor^composition^to^obtain^a^flavour^material.^^ Example^Ex18:^A^method^according^to^Example^Ex17,^further^comprising^a^step^of^adding^ to^the^cooled^gellan^gum^aqueous^solution^a^polysaccharide^selected^from^the^group^consisting^of^ guar,^ tamarind^ gum,^ sodium^ alginate,^ xanthan^ gum,^ sodium^ carboxymethyl^ cellulose,^ and^hydroxypropyl^methyl^cellulose.^^ Example^Ex19:^A^method^according^to^Example^Ex17^or^Example^Ex18,^further^comprising^a^ step^ of^ adding^ to^ the^ cooled^ gellan^ gum^ aqueous^ solution^ a^ salt^ selected^ from^ the^ group^consisting^ of calcium^ lactate,^ magnesium^ lactate,^ calcium^ carbonate,^ magnesium^ carbonate,^calcium^acetate^and^magnesium^acetate. Example^Ex20:^A^method^according^to^any^one^of^Examples^Ex17^to^Ex19,^wherein^the^salt^ comprises^one^or^more^of^calcium^lactate,^calcium^carbonate^and^calcium^acetate.^ Example^Ex21:^A^method^according^to^any^one^of^Examples^Ex17^to^Ex20,^wherein^the^salt^ may^is^calcium^lactate. Example^Ex22:^A^method^according^to^any^one^of^Examples Ex17 to^ Ex21,^wherein^the^emulsifier^is^lecithin.^^ Example^Ex23:^A^method^according^to^any^one^of^Examples^Ex17 to^Ex22,^wherein^the^step^of^applying^the^precursor^composition^onto^the^carrier^thread^material^comprises^dipping^the^ carrier^thread^material^into^the^precursor^composition.^^ Example^Ex24:^A^method^according^to^any^one^of^Examples^Ex17 to^Ex23,^wherein^the^step^of^applying^the^precursor^composition^onto^the^carrier^thread material^comprises^forming^a^layer^of^the^precursor^composition^over^the^carrier^sheet^material^having^a^thickness^of^at^least^ 10^micrometres.^^ Example^Ex25:^An^aerosol-generating^article^ comprising^a^ flavour^material,^wherein^ the^flavourant^is^releasable^from^the^flavour^material upon^heating the^aerosol-generating^article;^the^flavour^material^being^according^to^any^one^of^Examples^Ex^1^to^Ex^16.^^ Example^Ex26:^An^aerosol-generating^article^ comprising^a^ flavour^material,^wherein^ the^flavourant^is^releasable^from^the^flavour^material upon^heating the^aerosol-generating^article;^the^flavour^ material^ comprising:^ a^ polysaccharide^ matrix^ structure comprising^ gellan^ gum^ and^emulsifier;^a^flavourant^formulation^dispersed^within^the^polysaccharide^matrix^structure,^wherein^the^flavourant formulation^is^at^least^partly^trapped^within^the^polysaccharide^matrix^structure^and^releasable^from^the^polysaccharide^matrix^structure^upon^heating^of^the^flavour^material;^and a^ carrier^threadmaterial,^wherein^the^polysaccharide^matrix^structure^and^the^flavourant^formulation^ are^supported^by^the^carrier^thread^material.^^ Example^ Ex27:^ An^ aerosol-generating^ article^ according^ to^ Example^ Ex26,^ the^ article^comprising:^a^rod^of^aerosol-generating^substrate;^a^downstream^section^provided^downstream^ of^the^rod^of^aerosol-generating^substrate^and^extending^to^a^mouth^end^of^the^aerosol-generating^article;^ optionally^ an^ upstream^ section^ provided^ upstream^ of^ the^ rod^ of^ aerosol-generating^substrate^ and^ extending^ to^a^ distal^ end^ of^ the^aerosol-generating^ article;^ wherein^ the^ flavour^material^is^provided^in^at^least^one^of^the^rod^of^aerosol-generating^substrate;^the^downstream^section;^and^the^optional upstream^section.^^Example^Ex28:^An^aerosol-generating^article^according^to^Example^Ex26 or^Ex27,^wherein^the^carrier^thread^material^ is^a cotton^yarn;^wherein^the^aerosol-generating^article^comprises^a^rod^of^aerosol-generating^substrate;^a^downstream^section^provided^downstream^of^ the^ rod^of^aerosol-generating^ substrate^and^ extending^ to^ a^mouth^end^of^ the^aerosol-generating^article;^optionally^an^upstream^section^provided^upstream^of^the^rod^of^aerosol-generating^substrate^and^ extending^to^a^distal^end^of^the^aerosol-generating^article;^wherein^the^flavour^material^is^provided^ in^the^rod^of^aerosol-generating^substrate.^^^ Examples will^now^be^further^described^with^reference^to^the^figures^in^which:Figures 1a^and^1b show^a^schematic^side^cross-sectional^view^of^an^aerosol-generating^article^in^accordance^with^the^present^invention^comprising^a^flavour^material in^the^rod^of^aerosol-generating^substrate;^and Figure^2^shows^a^scanning^electron^microscope^image^of a^flavour^material^similar^to^that^of^the^present^invention,^except^that^the^carrier^material^is in^the^form^of a^sheet^and^not^a^thread.^^An^ aerosol-generating^ article^ 10^ in^ accordance^ with^ the^ present^ invention^ is^ shown^ in^Figures 1a^and^1b.^^The^aerosol-generating^article^10^shown^in^Figure^1a comprises^a^rod^12^of^aerosol-generating^substrate^and^a^downstream^section^14^at^a^location^downstream^of^the^rod^12^ of^ aerosol-generating^ substrate.^ ^ Further,^ the^ aerosol-generating^ article^ 10^ comprises^ an^upstream^section^16^at^a^location^upstream^of^the^rod^12^of^aerosol-generating^substrate.^^ A^ ventilation^ zone^ 60^ is^ provided^ at^ a^ location^ downstream^ of^ the^ rod^ 12^ of^ aerosol-generating^substrate.^^ In^more^detail,^ in^the^embodiment^of^Figure^1a,^the^downstream^section^14^comprises^a^mouthpiece^element^18^and^a^hollow^section^20.^^The^hollow^section^20^comprises^an^aerosol-cooling^ element^ 22^ comprising^ a^ hollow^ tubular^ element^ and^ the^ ventilation^ zone^ 60,^ which^comprises^a^ plurality^ of^ openings^ formed^ through^ a^wall^ of^ the^hollow^ tubular^ element.^ ^ The^aerosol-cooling^ element^ 22^ is^ positioned^ immediately^ downstream^ of^ the^ rod^ 12^ of^ aerosol-generating^ substrate.^ ^As^ shown^ in^ the^drawing^of^Figure^1,^ an^upstream^end^of^ the^aerosol-cooling^element^22^abuts^a^downstream^end^of^the^rod^12^of^aerosol-generating^substrate.^^The^ mouthpiece^element^18^is^positioned^immediately^downstream^of^the^aerosol-cooling^element^22.^^ As^shown^in^the^drawing^of^Figure^1a,^an^upstream^end^of^the^mouthpiece^element^18^abuts^a^ downstream^end^of^the^aerosol-cooling^element^22.^^The^mouthpiece^element^18^comprises^a^ plug^24^of^low-density^filtration^material.^^ The^rod^12^comprises^an^aerosol-generating^substrate^in^the^form^of^a^gathered^sheet^of^ homogenised^tobacco^material.^^However,^other^types^of^tobacco-containing^substrate,^such^as^ a^tobacco^cut^filler,^can^replace^the^gathered^sheet^of^homogenised^tobacco^material.^^^ The^upstream^section^16^comprises^a^cylindrical^plug^26^of^compressed^and^plasticised^ cellulose^acetate^circumscribed^by^a^wrapper^28.^^The^plug^26^of^the^upstream^section^16^has^a^ length^of^about^5^millimetres.^^^^ Further,^ the^aerosol-generating^article comprises^a flavour^material 50.^^In^more^detail,^a^flavour^material in^thread^form^is^disposed^within^the^rod^12.^^ In^Figure^1a,^the^flavour^material^50^comprises^a single^thread^52^extending^along^a^longitudinal^axis of^the^rod^12.^Figure^1b^is^otherwise^ identical^to^Figure^1a,^with^the^exception^that^flavour^material^50^comprises^multiple^threads^52a,^52b,^52c^extending^along^a^longitudinal^axis^of^the^rod^12.^The^flavour^material 50^is^of^the^type^described^in^detail^above.^^ Examples of^suitable^formulations for^the^flavour^material 50^and^processes for^forming^the^flavour^material 50^are set^out^below.^^Preparation^A - Flavour^material comprising^a^menthol^formulation^trapped^in^a^gellan^gum^polysaccharide^matrix^supported^on^a^carrier^thread^material (cotton^yarn)^^100^g^of^water^are^heated^to^about^60 degrees^Celsius^and^3.0 g of^gellan^gum^are^added^to^the^water^bath.^ The^resulting^mixture^is^homogenized^and^heated^to^a^temperature^in^the^range^from^ 80 to^ 85 degrees^ Celsius and^ kept^ at^ this^ temperature^ for^ 5^minutes.^ The^mixture^ is^subsequently^cooled^down^to^a^temperature^in^the^range^from^70 to^75 degrees^Celsius and^0.1^g^of^ lecithin^and^8.0^g^of^menthol^are^added^to^the^mixture.^ ^The^flavour-containing^mixture^ is^homogenized^for^3^minutes.^ Subsequently,^a^carrier^ thread^material^ is^dipped^in^the^resulting^aqueous^composition,^and^the^aqueous^composition^is^left^to^jellify^on^the^dipped^carrier^thread^material,^which^is dried^in a^still^oven^at^75 degrees^Celsius to^form^the^impregnated^carrier^thread^material.^ A^layer^comprising^a^gellan^gum^matrix^trapping^the^menthol^formulation^immobilised^on^the^cotton^yarn^is^obtained.^^ Preparation^B - Flavour^material comprising^a^menthol^formulation^trapped^in^a^gellan^gum^– guar polysaccharide^matrix^supported^on^a^carrier^thread^material (cotton^yarn)100^g^of^water^are^heated^to^about^60 degrees^Celsius^and^1.0 g of^gellan^gum^are^added^to^the^water^bath.^ The^resulting^mixture^is^homogenized^and^heated^to^a^temperature^in^the^range^from^ 80 to^ 85 degrees^ Celsius and^ kept^ at^ this^ temperature^ for^ 5^minutes.^ The^mixture^ is^subsequently^cooled^down^to^a^temperature^in^the^range^from^70 to^75 degrees^Celsius and^0.1^g^of^ lecithin^and^8.0^g^of^menthol^are^added^to^the^mixture.^ ^The^flavour-containing^mixture^ is^homogenized^for^3^minutes.^ Subsequently,^2.0^g^of^guar^are^added^to^the^mixture,^which^is^then^ homogenised^again^for^another^3^minutes.^^Subsequently,^a^carrier^thread^material^is^dipped^in^the^resulting^aqueous^composition,^and^the^aqueous^composition^ is^ left^to^ jellify on^the^dipped^carrier^thread^material,^which^is dried^in a^still^oven^at^75 degrees^Celsius to^form^the^impregnated^carrier^ thread^material.^ A^ layer^ comprising^ a^ gellan^ gum^ / ^ guar^matrix^ trapping^ the^menthol^formulation^immobilised^on^the^cotton^yarn is^obtained.^^Preparation^C^- Flavour^material^comprising^a^menthol^formulation^trapped^in^a^gellan^gum^– alginate polysaccharide^matrix^supported^on^a^carrier^thread^material^(cotton^yarn)100^g^of^water^are^heated^to^about^60 degrees^Celsius^and^2.0 g of^gellan^gum^and^0.5^g^of^alginate^are^added^to^the^water^bath.^ The^resulting^mixture^is^homogenized^and^heated^to^a^temperature^in^the^range^from^90 to^95 degrees^Celsius and^kept^at^this^temperature^for^5^minutes.^The^mixture^is^subsequently^cooled^down^to^a^temperature^in^the^range^from^70 to^75 degrees^Celsius and^0.1^g^of^lecithin^and^8.0^g^of^menthol^are^added^to^the^mixture.^^The^flavour-containing^mixture^is^homogenized^for^3^minutes.^ Subsequently,^a^carrier^thread^material^is^dipped^in^the^resulting^aqueous^composition,^and^the^aqueous^composition^is^left^to^jellify on^the^dipped^carrier^thread^material,^which^is dried^in a^still^oven^at^75 degrees^Celsius.^ A^layer^comprising^a gellan^gum^ / ^alginate^matrix^trapping^the^menthol^formulation^immobilised^on^the cotton^yarn is^obtained.^^Preparation^ D1 – Aerosol-generating^ article^ comprising^ a^ flavour^ material produced^according^to^Preparation^A An^amount^of^flavour^material produced^according^to^Preparation^A^making^up^for^an^overall^content^of^menthol^of^5^mg^was^added^to^the^rod^of^a^commercially^available^aerosol-generating^article (HEET®^by^Philip^Morris^Products^S.A.).^^Preparation^ D2 – Aerosol-generating^ article^ comprising^ a^ flavour^ material produced^according^to^Preparation^A An^amount^of^flavour^material^produced^according^to^Preparation^A^making^up^for^an^overall^ content^of^menthol^of^35^mg^was^added^to^the^rod^of^a^commercially^available^aerosol-generating^ article^(HEET®^by^Philip^Morris^Products^S.A.).^^ Preparation^ D3 – Aerosol-generating^ article^ comprising^ a^ flavour^ material produced^according^to^Preparation^A An^amount^of^flavour^material^produced^according^to^Preparation^A^making^up^for^an^overall^ content^of^menthol^of^37^mg^was^added^to^the^rod^of^a^commercially^available^aerosol-generating^ article^(HEET®^by^Philip^Morris^Products^S.A.).^ Similar^ flavour^materials^ to^ those^ in^ accordance^ with^ the^ present^ invention^ have^ been^prepared and^tested^as^proof^of^concept,^with^the^exception^that^in^these^materials,^the^carrier^material^is^in^the^form^of^a^sheet^^and^not^a^thread.^In^these^flavour^materials,^similar^to^the^flavour^materials^ of^ the^ present^ invention,^ the^ flavour^ material^ comprises^ a^ polysaccharide^ matrix^structure^comprising^a^gellan^gum^and^emulsifier,^a^flavourant^formulation^dispersed^within^the^ polysaccharide^matrix^structure,^wherein^the^flavourant^formulation^is^at^least^partly^trapped^within^ the^polysaccharide^matrix^structure^and^releasable^from^the^polysaccharide^matrix^structure;^and^ the^polysaccharide^matrix^structure^and^the^flavourant^formulation^are^supported^by^the^carrier^ material,^in^this^case,^a^sheet.^ Preparation^A’ - Flavour^material^comprising^a^menthol^formulation^trapped^in^a^gellan^gum^polysaccharide^matrix^supported^on^a^carrier^sheet^material^(paper^wrapper) 100^g^of^water^are^heated^to^about^60^degrees^Celsius^and^3.0^g^of^gellan^gum^are^added^ to^the^water^bath.^^The^resulting^mixture^is^homogenized^and^heated^to^a^temperature^in^the^range^from^ 80^ to^ 85^ degrees^ Celsius^ and^ kept^ at^ this^ temperature^ for^ 5^minutes.^ ^ The^mixture^ is^subsequently^cooled^down^to^a^temperature^in^the^range^from^70^to^75^degrees^Celsius^and^0.1^g^of^ lecithin^and^8.0^g^of^menthol^are^added^to^the^mixture.^ ^The^flavour-containing^mixture^ is^homogenized^for^3^minutes.^^Subsequently,^the^resulting^aqueous^composition^is^cast^on^a^sheet^ of^homogenised^tobacco^material^located^on^a^metallic^tray,^left^to^jellify^and^dried^in^a^still^oven^ at^75^degrees^Celsius.^^A^layer^comprising^a^gellan^gum^matrix^trapping^the^menthol^formulation^ immobilised^on^the^paper^wrapper^is^obtained.^^ Preparation^B1 - Flavour^material^comprising^a^menthol^formulation^trapped^in^a^gellan^gum^– guar polysaccharide^ matrix^ supported^ on^ a^ carrier^ sheet^ material^ (homogenised^ tobacco^material) 100^g^of^water^are^heated^to^about^60 degrees^Celsius^and^1.0 g of^gellan^gum^are^added^to^the^water^bath.^ The^resulting^mixture^is^homogenized^and^heated^to^a^temperature^in^the^range^from^ 80 to^ 85 degrees^ Celsius and^ kept^ at^ this^ temperature^ for^ 5^minutes.^ The^mixture^ is^subsequently^cooled^down^to^a^temperature^in^the^range^from^70 to^75 degrees^Celsius and^0.1^g^of^ lecithin^and^8.0^g^of^menthol^are^added^to^the^mixture.^ ^The^flavour-containing^mixture^ is^homogenized^for^3^minutes.^ Subsequently,^2.0^g^of^guar^are^added^to^the^mixture,^which^is^then^homogenised^again^for^another^3^minutes.^^Subsequently,^the^resulting^aqueous^composition^is^ cast^on^a^sheet^of^homogenised^tobacco^material^and^located^on^a^metallic^tray,^left^to^jellify^and^dried^in a^still^oven^at^75 degrees^Celsius.^ A^layer^comprising^a^gellan^gum^ / ^guar^matrix^trapping^the^menthol^formulation^immobilised^on^the^homogenised^tobacco^material^is^obtained.^^ Preparation^B2 - Flavour^material^comprising^a^menthol^formulation^trapped^in^a^gellan^gum^– guar polysaccharide^matrix^supported^on^a^carrier^sheet^material^(paper^wrapper)100^g^of^water^are^heated^to^about^60 degrees^Celsius^and^1.0 g of^gellan^gum^are^added^to^the^water^bath.^ The^resulting^mixture^is^homogenized^and^heated^to^a^temperature^in^the^range^from^ 80 to^ 85 degrees^ Celsius and^ kept^ at^ this^ temperature^ for^ 5^minutes.^ The^mixture^ is^subsequently^cooled^down^to^a^temperature^in^the^range^from^70 to^75 degrees^Celsius and^0.1^g^of^ lecithin^and^8.0^g^of^menthol^are^added^to^the^mixture.^ ^The^flavour-containing^mixture^ is^homogenized^for^3^minutes.^ Subsequently,^2.0^g^of^guar^are^added^to^the^mixture,^which^is^then^homogenised^again^for^another^3^minutes.^^Subsequently,^the^resulting^aqueous^composition^is^ cast^on^a^sheet^of^paper^wrapper^material^and^located^on^a^metallic^tray,^left^to^jellify^and^dried^ina^still^oven^at^75 degrees^Celsius.^ A^ layer^comprising^a^gellan^gum^ / ^guar^matrix^trapping^the^menthol^formulation^immobilised^on^the^paper^wrapper^material^is^obtained.^^ Preparation^C’ - Flavour^material^comprising^a^menthol^formulation^trapped^in^a^gellan^gum^– alginate polysaccharide^matrix^supported^on^a^carrier^sheet^material^ (homogenised^tobacco^material) 100^g^of^water^are^heated^to^about^60 degrees^Celsius^and^2.0 g of^gellan^gum^and^0.5^g^of^alginate^are^added^to^the^water^bath.^ The^resulting^mixture^is^homogenized^and^heated^to^a^temperature^in^the^range^from^90^to^95 degrees^Celsius and^kept^at^this^temperature^for^5^minutes.^The^mixture^is^subsequently^cooled^down^to^a^temperature^in^the^range^from^70 to^75 degrees^Celsius and^0.1^g^of^lecithin^and^8.0^g^of^menthol^are^added^to^the^mixture.^^The^flavour-containing^mixture^is^homogenized^for^3^minutes.^ Subsequently,^the^resulting^aqueous^composition^is^cast^on^a^sheet^of^homogenised^tobacco^material^and^located^on^a^metallic^tray,^left^to^jellify^and^dried^in a^still^oven^at^75 degrees^Celsius.^ A^layer^comprising^a^gellan^gum^ / ^alginate^matrix^trapping^the^menthol^formulation^immobilised^on^the^homogenised^tobacco^material^is^obtained.^^ Preparation^ D1’ – Aerosol-generating^ article^ comprising^ a^ flavour^ material produced^according^to^Preparation^A’ An^amount^of^flavour^material^produced^according^to^Preparation^A’^making^up^for^an^overall^ content^of^menthol^of^5^mg^was^added^to^the^rod^of^a^commercially^available^aerosol-generating^ article^(HEET®^by^Philip^Morris^Products^S.A.).^^ Preparation^ D2’ – Aerosol-generating^ article^ comprising^ a^ flavour^ material produced^according^to^Preparation^A’ An^amount^of^flavour^material^produced^according^to^Preparation^A’^making^up^for^an^overall^ content^of^menthol^of^35^mg^was^added^to^the^rod^of^a^commercially^available^aerosol-generating^ article^(HEET®^by^Philip^Morris^Products^S.A.).^^ Preparation^ D3’ – Aerosol-generating^ article^ comprising^ a^ flavour^ material produced^according^to^Preparation^A’ An^amount^of^flavour^material^produced^according^to^Preparation^A’^making^up^for^an^overall^ content^of^menthol^of^37^mg^was^added^to^the^rod^of^a^commercially^available^aerosol-generating^ article^(HEET®^by^Philip^Morris^Products^S.A.).^^ Morphologic^characterisation Figure^2^shows^a^scanning^electron^microscope^(SEM)^ image^of^ the flavour^material 50^produced^in^accordance^with^Preparation^B1 embedded^in^a^wax.^^It^can^be^seen^from^the^image^that^ the^ internal^ structure^of^ the^ flavour^material includes a^matrix^ 52^with^a^plurality^of^ small^pockets 54 adapted^to^trap^the^flavour^composition,^the^pockets^54 being^dispersed^through^the^matrix 52.^^The^pockets are^relatively^uniformly^distributed^through^the^material^and^are^relatively^consistent^in^size.^^The^flavour^material 50^further^comprises^a^carrier^sheet^material^56^ in^the^form^of^a^sheet^of^homogenised^tobacco^material,^ the^carrier^sheet^material^56^supporting^the^matrix^52.^^ Preparation^B^in^accordance^with^the^present^ invention,^ in^which^the^carrier^sheet^material^56^is^replaced^by^a^carrier^thread^material,^is^expected^to^exhibit^a^similar^morphology^to^Preparation^B1,^with^a^matrix^52^with^a^plurality^of^small^pockets 54 adapted^to^trap^the^flavour^composition,^the^pockets^54 being^dispersed^through^the^matrix 52.^Thermogravimetric^analysis The^flavour^release^profile^of^the^flavour^material produced^according^to^the^Preparations^above^may^be^analysed^in^a^thermogravimetric^analysis^(TGA).^^The^TGA^test^is^carried^out^using^ a^thermogravimetric^machine^coupled^to^a^mass^spectrometer,^or^similar^TGA^equipment.^^In^the^analysis^the^flavour^material is^heated^from^25 degrees^Celsius to^400 degrees^Celsius in^an^inert^nitrogen^atmosphere^with^the^temperature^being^increased^at^a^rate^of^15 degrees^Celsius per^minute^and^with^an^air^flow^of^60^ml^per^minute.^^As^the^temperature^is^increased,^the^release^of^ menthol^is^assessed^by^detecting^the^menthol^molecules^by^way^of^a^specific^ion^representative^ of^menthol.^^ Data^collected^carrying^out^TGA^tests^on^flavour^materials^in^accordance^with^the^invention^can^ be^ compared^ with^ data^ collected^ carrying^ out^ an^ equivalent^ TGA^ test^ on^ the^ flavourant^formulation^alone^(e.g.^pure^menthol).^^One^such^comparison^may^provide^some^information^about^release^mechanisms^and dynamics,^which^may^be^help^fine^tune^a^flavourant^release^profile^when^the^flavour^material is^incorporated^in^an^aerosol-generating^article.^^^^When^heated^ in^ the^ thermogravimetric^analysis^described,^ pure^menthol^was^ released^unimodally^between^50^degrees^Celsius^and^166^degrees^Celsius,^with^a^maximum^around^138^ degrees^Celsius.^^ By^contrast,^when^heated^in^the^thermogravimetric^analysis^described,^the^flavour^materialproduced^according^to^Preparation^B2 was^found^to^provide^a^multi^modal^release^of^menthol.^^A^first,^smaller fraction^of^the^menthol^was^released^between^about^57 degrees^Celsius^and^about^137 degrees^Celsius,^with^a^local^maximum^at^about^116 degrees^Celsius.^^A^second,^much^more^consistent fraction^of^ the^menthol^was^ released^between^about^229^degrees^Celsius^and^264degrees^Celsius^with^a^local^maximum^at^about^243 degrees^Celsius.^^A^third,^smaller fraction^of^the^menthol^was^released^between^about^265^degrees^Celsius^and^302 degrees^Celsius^with^a^local^maximum^at^about^279 degrees^Celsius.^^Release^of^the^first^ fraction^of^menthol^with^a^maximum^just^above^115 degrees^Celsius^may^suggest^that^some^of^the^menthol^formulation^is^solubilised^or^relatively^weakly^immobilised^within^the^ flavour^material.^ ^On^ the^other^hand,^ release^of^ the^second,^much^ larger fraction^of^menthol^with^a^maximum^above^240^degrees^Celsius^– a^temperature^which^may^be^associated^with^the^thermal^degradation of^gellan^gum – may support^the^hypothesis^that^a^significant^portion^of^the^menthol^formulation^is^in^effect^trapped^within^the^matrix^structure,^and^has^some^stronger^ interaction^with^the^gellan^gum^in^the^matrix^structure.^^Release^of^the^remainder^of^the^menthol^at^even^higher^ temperatures^may^suggest^ that^ the^menthol^ formulation^ interacts^ in^a^different^manner^with,^and^is^even^more^stably^held^by, the^guar^in^the^matrix^structure.^^^The^ same^TGA^ test^was^carried^out^ on^ a^ flavour^material prepared^ in^accordance^with^Preparation^A’.^^This^flavour^material was^also^found^to^provide^a^multimodal^release^of^menthol.^^A^first,^smaller fraction^of^the^menthol^was^released^between^about^57 degrees^Celsius^and^about^239 degrees^ Celsius,^ with^ a^ local^ maximum^ around^ 200 degrees^ Celsius.^ ^ A^ second,^ more^significant^fraction^of^the^menthol^was^released^between^240 degrees^Celsius^and^306 degrees^Celsius,^with^a^local^maximum^at^around^249 degrees^Celsius.^^One^further^fraction^of^the^menthol^was^released^between^about^307^degrees^Celsius^and^about^384^degrees^Celsius,^with^a^local^ maximum^at^around^351^degrees^Celsius.^^ Release^of^ the^ first^ fraction^of^menthol^around^200 degrees^Celsius^may^suggest^that^a^small^ portion^ of^ the^ menthol^ formulation^ contained^ in^ the^ flavour^ material is^ less^ strongly^immobilised,^whereas^the^greater^part^of^the^menthol^formulation^contained^in^the^flavour^material being^released^at^higher^temperatures^appears^to^suggest^a^stronger^interaction^with^the^gellan^ gum,^which^results^in^an^effective^immobilisation.^^ A^comparison^between^the^menthol^release^profiles of^flavour^materials^prepared^according^to^Preparations^B2 and^A’^demonstrates^ that^adjusting^ the^ composition^of^ the^polysaccharide^matrix^– for^example,^using^gellan^gum^alone^or^in^combination^with^another^polysaccharide^–may^ help^ fine^ tune^ flavour^ delivery^ when^ the^ flavour^material is^ incorporated^ in^ an^ aerosol-generating^article.^^In^particular,^it^may^be^possible^to^control^at^what^temperature^flavour^release^is^ initiated^ and^ around^ what^ temperature^ flavour^ release^ is^ maximised.^ ^ Additionally,^ flavour^materials^ which,^ like^ the^ ones^ prepared^ according^ to^ Preparations^ B2 and^ A’,^ have^ different^flavour^release^profiles^with^local^maxima^at^different^temperatures, may^be^combined^in^a^single^aerosol-generating^articles^to^provide^an^even^broader^range^of^ flavour^delivery^options^to^the^consumer.^^ Preparations^A^and^B^in^accordance^with^the^present^invention,^in^which^the^carrier^material^is^a^thread^and^not^a^sheet,^are^expected^to^exhibit^similar^thermogravimetric^analysis^profiles to^Preparations^A’^and^B2^described^above. Thermal^stability The^ thermal^ stability^ under^ stress^ conditions^of^ a flavour^material may^ be^ assessed^ by^ageing^the^flavour^material at^a^constant^temperature^and^monitoring^its^weight^loss^over^time.^^To^this^purpose^samples^of^the^flavour^material,^in^which^the^carrier^material^is^in^the^form^of^a^sheet,^and^not^a^thread^as^in^the^present^invention, are^cut^into^regular^and^homogenously^sized^pieces^are^weighed^and^distributed^in^a^series^of^Schott^glass^open^bottles.^ ^The^samples^are^aged^in^a^laboratory^oven^set^at^50^degrees^Celsius^for^a^period^of^two^weeks.^^For^the^flavour^material produced^ in^ accordance^with^ Preparation^A’,^ a^weight^ loss^of^ about^ 35 percent^was^measured^at^the^end^of^the^test.^^It^is^hypothesised^that^such^weight^loss^value^accounts^not^only^for^some^migration^of^flavour^species,^but^also^for^ losses^of^humidity^and^glycerol,^and^so^it^ is^considered^to^be^satisfactory.^^ Preparation^A^in^accordance^with^the^present^invention,^in^which^the^carrier^material^is^in^ the^form^of^a^thread^and^not^a^sheet,^is^expected^to^exhibit^similar^thermal^stability^behaviour^to^ that^described^above^for^Preparation^A’. Puff-by-puff^flavour^delivery^assessment Flavour^ delivery^ of^ an^ aerosol-generating^ article^ incorporating^ a^ flavour^ material in^accordance^with^the^present^invention^may^be^assessed^by^heating^the^aerosol-generating^article^ in^a^commercially^available,^compatible^heating^device^and^measuring^the^menthol^delivered^at^ the^mouth^end^of^the^article^with^every^puff.^^ In^more^ detail,^ the^ products^ released^with^each^puff^ from^ the^ aerosol-generating^article^heated^by^the^heating^device^may^be^analysed^using^Proton^Transfer^Mass^Spectrometry^(PTR- MS).^^ The^puff-by-puff^menthol^delivery^of^an^aerosol-generating^article^produced^in^accordance^with^ Preparations D1’,^ D2’ and^D3’ was^measured.^ ^ Their^ behaviour^was^ compared^with^ the^behaviour^ of^ a^ commercially^ available^ aerosol-generating^ article^ (HEET®^ by^ Philip^ Morris^Products^S.A.)^loaded with^5^mg^of^pure^menthol.It^was^observed^that^the^commercially^available^aerosol-generating^article^loaded^with^pure^ menthol^reached^its^maximum^menthol^delivery^around^at^the^third^puff,^which^was^followed^by^a^ gradual^decrease^in^the^menthol^level.^^By^contrast,^with^aerosol-generating^articles^produced^in^accordance^with^Preparations^D1’,^D2’ and^D3’,^the^menthol^delivery^appeared^to^increase^until^the^third^puff^and^was^subsequently^substantially^maintained^around^the^same^levels^throughout^ the^use^cycle^of^the^article^and^until^the^twelfth^puff. Preparations^D1,^D2^and^D3^in^accordance^with^the^present^invention,^in^which^the^carrier^material^ is^ in^the^form^of^a^thread^and^not^a^sheet,^are^expected^to^exhibit^similar^puff-by-puff^flavour^delivery^behaviour^to^Preparations^D1’,^D2’^and^D3’^described^above.^^^^ For^ the^ purpose^ of^ the^ present^ description^ and^ of^ the^ appended^ claims,^ except^ where^otherwise^indicated,^all^numbers^expressing^amounts,^quantities,^percentages,^and^so^forth,^are^ to^be^understood^as^being^modified^in^all^instances^by^the^term^"about".^Also,^all^ranges^include^ the^maximum^and^minimum^points^disclosed^and^include^any^intermediate^ranges^therein,^which^may^or^may^ not^ be^ specifically^ enumerated^ herein.^ In^ this^ context,^ therefore,^ a^number^ A^ is^understood^ as^ A^ ±^ 5% of^ A.^Within^ this^ context,^ a^ number^ A^may^ be^ considered^ to^ include^numerical^values^that^are^within^general^standard^error^for^the^measurement^of^the^property^that^ the^number^A^modifies.^^The^number^A,^in^some^instances^as^used^in^the^appended^claims,^may^deviate^by^the^percentages^enumerated^above^provided^ that^ the^amount^by^which^A^deviates^does^not^materially^affect^the^basic^and^novel^characteristic(s)^of^the^claimed^invention.^Also,^all^ ranges^include^the^maximum^and^minimum^points^disclosed^and^include^any^intermediate^ranges^ therein,^which^may^or^may^not^be^specifically^enumerated^herein.

Claims

1. A flavoring material for use in an aerosol generating article, wherein the flavoring substance is released from said flavoring material upon heating of the flavoring material, comprising polysaccharide matrix structure containing gellan gum and emulsifier; a flavoring composition dispersed within a polysaccharide matrix structure, wherein said flavoring composition is at least partially contained within the polysaccharide matrix structure and is released from said polysaccharide matrix structure upon heating of the flavoring material; a carrier thread-like material, wherein the polysaccharide matrix structure and the flavor composition are supported by said carrier thread-like material.

2. The flavoring material according to claim 1, wherein the polysaccharide matrix structure comprises gellan gum as the only polysaccharide or gellan gum in combination with at least an additional polysaccharide selected from the group consisting of guar gum, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethylcellulose and hydroxypropyl methylcellulose.

3. The flavoring material according to claim 1 or 2, wherein the gellan gum constitutes from 5% by weight to 99.9% by weight relative to the weight of the flavoring material on a dry weight basis.

4. A flavoring material according to any one of paragraphs 1-3, further comprising a polyol having the formula C n H 2n+2 O n, wherein said polyol is preferably selected from the group consisting of glycerol, sorbitol, xylitol, mannitol and erythritol, or said polyol is preferably from 0.01% by weight to 20% by weight relative to the weight of the flavoring material on a dry weight basis, or both.

5. The flavoring material of claim 4, wherein the carrier filamentary material is a yarn comprising cellulose fibers, and wherein the cellulose fibers comprise fibers obtained from one or more plants, such as cotton fibers, flax fibers, hemp fibers, bamboo fibers, sisal fibers, ramie fibers, coconut fibers, kenaf fibers, abaca fibers and jute fibers, or regenerated cellulose fibers.

6. A flavoring material according to any one of the preceding claims, wherein the carrier thread-like material is cotton yarn.

7. A flavouring material according to any one of the preceding claims, wherein the polysaccharide matrix structure and the flavouring composition form a layer on a carrier thread-like material, wherein the thickness of said layer is at least 10 micrometres and preferably less than 150 micrometres.

8. A flavouring material according to any one of the preceding claims, wherein the polysaccharide matrix may comprise a calcium salt or a magnesium salt or both, for example one or more salts selected from calcium lactate, magnesium lactate, calcium carbonate, magnesium carbonate, calcium acetate and magnesium acetate.

9. A method for producing a flavoring material for use in an aerosol generating product, comprising heating water to a temperature of at least 50°C; dispersing gellan gum in heated water to obtain an aqueous dispersion of gellan gum; heating an aqueous dispersion of gellan gum to a temperature of at least 80°C to dissolve the gellan gum and obtain an aqueous solution of gellan gum; cooling the aqueous solution of gellan gum to a temperature of 65°C to 75°C; adding a flavoring composition and an emulsifier to a cooled aqueous solution of gellan gum to obtain a precursor composition; applying a precursor composition to a carrier thread-like material; drying the carrier thread-like material with the applied precursor composition to obtain a flavoring material.

10. The method of claim 9, further comprising the step of adding to the cooled aqueous solution of gellan gum a polysaccharide selected from the group consisting of guar gum, tamarind gum, sodium alginate, xanthan gum, sodium carboxymethylcellulose, and hydroxypropyl methylcellulose.

11. The method according to claim 9 or 10, wherein the step of applying the precursor composition to the carrier thread-like material comprises immersing said carrier thread-like material in the precursor composition.

12. The method according to any one of claims 9-11, wherein the step of applying the precursor composition to the carrier thread-like material comprises forming a layer of the precursor composition on top of the carrier thread-like material of a thickness of at least 10 micrometers.

13. An aerosol generating article comprising a flavoring material, wherein the flavoring substance is released from said flavoring material upon heating of the aerosol generating article, wherein the flavoring material comprises polysaccharide matrix structure containing gellan gum and emulsifier; a flavoring composition dispersed within a polysaccharide matrix structure, wherein said flavoring composition is at least partially contained within the polysaccharide matrix structure and is released from said polysaccharide matrix structure upon heating of the flavoring material; and a carrier thread-like material, wherein the polysaccharide matrix structure and the flavor composition are supported by said carrier thread-like material.

14. The aerosol-generating article of claim 13, comprising a rod of an aerosol-generating substrate; a distal section located downstream of the rod of an aerosol-generating substrate and extending toward a mouthpiece end of the aerosol-generating article; optionally a proximal section located upstream of the rod of an aerosol-generating substrate and extending toward a distal end of the aerosol-generating article; and wherein the flavoring material is housed in at least one of the rod of an aerosol-generating substrate, the distal section, and the optional proximal section.

15. An aerosol-generating article according to claim 13 or 14, wherein the supporting filamentary material is cotton yarn; wherein the aerosol-generating article comprises a rod of an aerosol-generating substrate; a distal section located downstream of the rod of an aerosol-generating substrate and extending toward the mouthpiece end of the aerosol-generating article; optionally a proximal section located upstream of the rod of an aerosol-generating substrate and extending toward the distal end of the aerosol-generating article; wherein the said flavoring material is housed in the rod of an aerosol-generating substrate.