Hydroxymethylfurfural: Difference between revisions

{{short description|Chemical compound}}

| verifiedrevid = 443863132

| Name = Hydroxymethylfurfural

| ImageFile = Hydroxymethylfurfural-2D-skeletal.png

| ImageAlt = Structural formula of hydroxymethylfurfural

| ImageFile1 = Hydroxymethylfurfural 3D ball.png

| ImageAlt1 = Ball-and-stick model of the hydroxymethylfurfural molecule

| ImageFile2 = Hydroxymethylfurfural 3D spacefill.png

| ImageAlt2 = Space-filling model of the hydroxymethylfurfural molecule

| ImageName = Hydroxymethylfurfural

| PIN = 5-(Hydroxymethyl)furan-2-carbaldehyde<ref name=iupac2013>{{cite book | title = Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher = [[Royal Society of Chemistry|The Royal Society of Chemistry]] | date = 2014 | location = Cambridge | page = 911 | doi = 10.1039/9781849733069-FP001 | isbn = 978-0-85404-182-4| chapter = Front Matter }}</ref>

| OtherNames = 5-(Hydroxymethyl)-2-furaldehyde<ref name=iupac2013/><br />5-(Hydroxymethyl)furfural<ref name=iupac2013/>

|Section1={{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| CASNo_Ref = {{cascite|correct|CAS}}

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 412516

| Beilstein = 110889

| Gmelin = 278693

| PubChem = 237332

| EC_number = 200-654-9

| UNII = 70ETD81LF0

|Section2={{Chembox Properties

| Appearance = Low melting white solid

| Odor = Buttery, caramel

| C = 6 | H = 6 | O =3

| Density = 1.29 g/cm³

| MeltingPtC = 30 to 34

| MeltingPt_notes =

| BoilingPtC = 114 to 116

| BoilingPt_notes = (1 mbar)

| LambdaMax = 284 nm<ref>The Determination of HMF in Honey with an Evolution Array UV-Visible Spectrophotometer. Nicole Kreuziger Keppy and Michael W. Allen, Ph.D., Application note 51864, Thermo Fisher Scientific, Madison, WI, USA ([http://www.analiticaweb.com.br/newsletter/11/51864-UV-Furfural_Mel.pdf article])</ref>

|Section3={{Chembox Related

| OtherFunction_label = furan-2-carbaldehydes

| OtherFunction = [[Furfural]]<br />

}}

| Section7 = {{Chembox Hazards

| GHSPictograms = {{GHS07}}<ref name="sigma">{{Sigma-Aldrich|id=W501808|name=5-(Hydroxymethyl)furfural|access-date=2017-05-23}}</ref>

| GHSSignalWord = Warning<ref name="sigma" />

| HPhrases = {{H-phrases|315|319|335}}<ref name="sigma" />

| PPhrases = {{P-phrases|261|305+351+338|310}}<ref name="sigma" />

'''Hydroxymethylfurfural''' ('''HMF'''), also known as '''5-(hydroxymethyl)furfural''', is an [[organic compound]] formed by the [[Dehydration reaction|dehydration]] of reducing sugars.<ref name="van Puttenvan der Waal2013">{{cite journal|last1=van Putten|first1=Robert-Jan|last2=van der Waal|first2=Jan C.|last3=de Jong|first3=Ed|last4=Rasrendra|first4=Carolus B.|last5=Heeres|first5=Hero J.|last6=de Vries|first6=Johannes G.|title=Hydroxymethylfurfural, A Versatile Platform Chemical Made from Renewable Resources|journal=Chemical Reviews|volume=113|issue=3|year=2013|pages=1499–1597|issn=0009-2665|doi=10.1021/cr300182k|pmid=23394139}}</ref><ref name="RosatellaSimeonov2011">{{cite journal|last1=Rosatella|first1=Andreia A.|last2=Simeonov|first2=Svilen P.|last3=Frade|first3=Raquel F. M.|last4=Afonso|first4=Carlos A. M.|title=5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications|journal=Green Chemistry|volume=13|issue=4|year=2011|pages=754|issn=1463-9262|doi=10.1039/c0gc00401d}}</ref> It is a white low-melting solid (although commercial samples are often yellow) which is highly soluble in both water and organic solvents. The molecule consists of a [[furan]] ring, containing both [[aldehyde]] and [[Alcohol (chemistry)|alcohol]] functional groups.

HMF can form in sugar-containing food, particularly as a result of heating or cooking. Its formation has been the topic of significant study as HMF was regarded as being potentially carcinogenic to humans. However, so far in vivo genotoxicity was negative. No relevance for humans concerning carcinogenic and genotoxic effects can be derived.<ref name=":0">{{Cite journal|last1=Abraham|first1=Klaus|last2=Gürtler|first2=Rainer|last3=Berg|first3=Katharina|last4=Heinemeyer|first4=Gerhard|last5=Lampen|first5=Alfonso|last6=Appel|first6=Klaus E.|date=2011-04-04|title=Toxicology and risk assessment of 5-Hydroxymethylfurfural in food|journal=Molecular Nutrition & Food Research|volume=55|issue=5|pages=667–678|doi=10.1002/mnfr.201000564|pmid=21462333|issn=1613-4125}}</ref> HMF is classified as a food improvement agent <ref>{{Cite web|url=https://pubchem.ncbi.nlm.nih.gov/source/EU%20Food%20Improvement%20Agents|title=EU Food Improvement Agents - PubChem Data Source|last=PubChem|website=pubchem.ncbi.nlm.nih.gov|access-date=2018-06-25}}</ref> and is primarily being used in the food industry in form of a [[food additive]] as a biomarker as well as a flavoring agent for food products.<ref>{{Citation|title=Commission Implementing Regulation (EU) No 872/2012 of 1 October 2012 adopting the list of flavouring substances provided for by Regulation (EC) No 2232/96 of the European Parliament and of the Council, introducing it in Annex I to Regulation (EC) No 1334/2008 of the European Parliament and of the Council and repealing Commission Regulation (EC) No 1565/2000 and Commission Decision 1999/217/EC Text with EEA relevance|date=2012-10-02|url=http://data.europa.eu/eli/reg_impl/2012/872/oj/eng|issue=32012R0872|access-date=2018-06-25}}</ref><ref>{{Cite web|url=https://pubchem.ncbi.nlm.nih.gov/compound/237332#section=Top|title=5-(Hydroxymethyl)-2-furaldehyde|last=Pubchem|website=pubchem.ncbi.nlm.nih.gov|access-date=2018-06-25}}</ref> It is also produced industrially on a modest scale<ref name="Kläusli2014">{{cite journal|last1=Kläusli|first1=Thomas|title=AVA Biochem: commercialising renewable platform chemical 5-HMF|journal=Green Processing and Synthesis|volume=3|issue=3|year=2014|pages=235–236 |issn=2191-9550|doi=10.1515/gps-2014-0029|s2cid=100848139|doi-access=free}}</ref> as a [[carbon-neutral]] feedstock for the production of fuels<ref>{{cite journal | last1 = Huber | first1 = George W. | last2 = Iborra | first2 = Sara | last3 = Corma | first3 = Avelino | title = Synthesis of Transportation Fuels from Biomass: Chemistry, Catalysts, and Engineering | journal = [[Chem. Rev.]] | volume = 106 | pages = 4044–98 | year = 2006 | doi = 10.1021/cr068360d | issue = 9 | pmid=16967928| url = https://works.bepress.com/cgi/viewcontent.cgi?article=1058&context=george_huber }}[http://www.technologyreview.com/Nanotech/18943/ MIT Technology Review]</ref> and other chemicals.<ref name=arkat>{{Cite journal |last=Lewkowski |first=J. |year=2001 |title=Synthesis, chemistry and applications of 5-hydroxymethyl-furfural and its derivatives |journal=Arkivoc |volume=1 |pages=17–54 |issn=1424-6376 |doi=10.3998/ark.5550190.0002.102 |doi-access=free|hdl=2027/spo.5550190.0002.102 |hdl-access=free }}</ref>

== Production and reactions ==

HMF was first reported in 1875 as an intermediate in the formation of [[levulinic acid]] from sugar and sulfuric acid.<ref name="GroteTollens1875">{{cite journal|last1=Grote|first1=A. Freiherrn V.|last2=Tollens|first2=B.|title=Untersuchungen über Kohlenhydrate. I. Ueber die bei Einwirkung von Schwefelsäure auf Zucker entstehende Säure (Levulinsäure)|journal=Justus Liebig's Annalen der Chemie|volume=175|issue=1–2|year=1875|pages=181–204|issn=0075-4617|doi=10.1002/jlac.18751750113|url=https://zenodo.org/record/1427341}}</ref> This remains the classical route, with 6-carbon [[sugars]] ([[hexoses]]) such as [[fructose]] undergoing acid catalyzed poly-dehydration.<ref>{{cite journal | title = Phase Modifiers Promote Efficient Production of Hydroxymethylfurfural from Fructose |author1=Yuriy Román-Leshkov |author2=Juben N. Chheda |author3=James A. Dumesic | journal = [[Science (journal)|Science]] | year = 2006 | volume = 312 | issue = 5782 | pages = 1933–1937 | doi = 10.1126/science.1126337 | pmid = 16809536|bibcode=2006Sci...312.1933R |s2cid=38432592 }}</ref><ref>{{cite journal | doi = 10.15227/orgsyn.093.0029 | volume=93 | title=Synthesis of 5-(Hydroxymethyl)furfural (HMF) | year=2016 | journal=Organic Syntheses | pages=29–36 | last1 = Simeonov | first1 = Svilen| doi-access=free }}</ref> When [[hydrochloric acid]] is used [[5-Chloromethylfurfural|5-chloromethylfurfural]] is produced instead of HMF. Similar chemistry is seen with 5-carbon sugars ([[pentoses]]), which react with aqueous acid to form [[furfural]].

[[Image:NewhydroxymethylfurfuralSynthesis.png|500px|thumb|center|fructopyranose '''1''', fructofuranose '''2''', two intermediate stages of [[Dehydration reaction|dehydration]] (not isolated) '''3,4''' and finally HMF '''5''']]

The classical approach tends to suffer from poor yields as HMF continues to react in aqueous acid, forming [[levulinic acid]].<ref name="van Puttenvan der Waal2013" /> As sugar is not generally soluble in solvents other than water, the development of high-yielding reactions has been slow and difficult; hence while furfural has been produced on a large scale since the 1920s,<ref>{{cite journal|last1=Brownlee|first1=Harold J.|last2=Miner|first2=Carl S.|title=Industrial Development of Furfural|journal=Industrial & Engineering Chemistry|volume=40|issue=2|year=1948|pages=201–204|issn=0019-7866|doi=10.1021/ie50458a005}}</ref> HMF was not produced on a commercial scale until over 90 years later. The first production plant coming online in 2013.<ref name="Kläusli2014" /> Numerous synthetic technologies have been developed, including the use of [[ionic liquids]],<ref name="ZakrzewskaBogel-Łukasik2011">{{cite journal|last1=Zakrzewska|first1=Małgorzata E.|last2=Bogel-Łukasik|first2=Ewa|last3=Bogel-Łukasik|first3=Rafał|title=Ionic Liquid-Mediated Formation of 5-Hydroxymethylfurfural—A Promising Biomass-Derived Building Block|journal=Chemical Reviews|volume=111|issue=2|year=2011|pages=397–417|issn=0009-2665|doi=10.1021/cr100171a|pmid=20973468}}</ref><ref>{{cite journal|last1=Eminov|first1=Sanan|last2=Wilton-Ely|first2=James D. E. T.|last3=Hallett|first3=Jason P.|title=Highly Selective and Near-Quantitative Conversion of Fructose to 5-Hydroxymethylfurfural Using Mildly Acidic Ionic Liquids|journal=ACS Sustainable Chemistry & Engineering|date=2 March 2014|volume=2|issue=4|pages=978–981|doi=10.1021/sc400553q|doi-access=free|hdl=10044/1/31478|hdl-access=free}}</ref> continuous [[liquid-liquid extraction]], [[reactive distillation]] and [[Acid catalysis#Solid acid catalysts|solid acid catalysts]] to either remove the HMF before it reacts further or to otherwise promote its formation and inhibit its decomposition.<ref name="TeongYi2014">{{cite journal|last1=Teong|first1=Siew Ping|last2=Yi|first2=Guangshun|last3=Zhang|first3=Yugen|title=Hydroxymethylfurfural production from bioresources: past, present and future|journal=Green Chemistry|volume=16|issue=4|year=2014|pages=2015|issn=1463-9262|doi=10.1039/c3gc42018c}}</ref>

=== Derivatives ===

HMF itself has few applications. It can however be converted into other more useful compounds.<ref name=arkat /> Of these the most important is [[2,5-Furandicarboxylic acid|2,5-furandicarboxylic acid]], which has been proposed as a replacement for [[terephthalic acid]] in the production of [[polyesters]].<ref>{{cite journal|last1=Sousa|first1=Andreia F.|last2=Vilela|first2=Carla|last3=Fonseca|first3=Ana C.|last4=Matos|first4=Marina|last5=Freire|first5=Carmen S. R.|last6=Gruter|first6=Gert-Jan M.|last7=Coelho|first7=Jorge F. J.|last8=Silvestre|first8=Armando J. D.|title=Biobased polyesters and other polymers from 2,5-furandicarboxylic acid: a tribute to furan excellency|journal=Polym. Chem.|volume=6|issue=33|year=2015|pages=5961–5983|issn=1759-9954|doi=10.1039/C5PY00686D}}</ref><ref>{{cite journal |last1=Zhang |first1=Daihui |last2=Dumont |first2=Marie-Josée |title=Advances in polymer precursors and bio-based polymers synthesized from 5-hydroxymethylfurfural |journal=Journal of Polymer Science Part A: Polymer Chemistry |date=1 May 2017 |volume=55 |issue=9 |pages=1478–1492 |doi=10.1002/pola.28527|bibcode=2017JPoSA..55.1478Z |doi-access=free |hdl=20.500.11794/100964 |hdl-access=free }}</ref> HMF can be converted to [[2,5-dimethylfuran]] (DMF), a liquid that is a potential biofuel with a greater energy content than [[bioethanol]]. [[Hydrogenation]] of HMF gives [[2,5-bis(hydroxymethyl)furan]]. Acid-catalysed hydrolysis converts HMF into gamma-hydroxyvaleric acid and [[gamma-valerolactone]], with loss of formic acid.<ref name="RosatellaSimeonov2011"/><ref name="van Puttenvan der Waal2013" />

== Occurrence in food ==

HMF is practically absent in fresh food, but it is naturally generated in sugar-containing food during heat-treatments like drying or cooking. Along with many other flavor- and color-related substances, HMF is formed in the [[Maillard reaction]] as well as during [[caramelization]]. In these foods it is also slowly generated during storage. Acid conditions favour generation of HMF.<ref name = Arribas-Lorenzo>{{cite journal | pmid = 20005914 | last1 = Arribas-Lorenzo | year = 2010 | first1 = G | pages = 644–9 | issue = 2 | volume = 48 | last2 = Morales | first2 = FJ | title = Estimation of dietary intake of 5-hydroxymethylfurfural and related substances from coffee to Spanish population | journal = [[Food and Chemical Toxicology]] | doi = 10.1016/j.fct.2009.11.046 | hdl = 10261/82147 }}</ref> HMF is a well known component of baked goods. Upon toasting bread, the amount increases from 14.8 (5 min.) to 2024.8&nbsp;mg/kg (60 min).<ref name=RosatellaSimeonov2011/> It is also formed during coffee roasting, with up to 769&nbsp;mg/kg.<ref>{{cite journal |title= A novel UHPLC method for determining the degree of coffee roasting by analysis of furans|journal=Food Chemistry |volume=341|pages=128165 |doi=10.1016/j.foodchem.2020.128165|issn=0308-8146|year=2021|last1=Macheiner |first1=Lukas |last2=Schmidt |first2=Anatol |last3=Karpf |first3=Franz |last4=Mayer |first4=Helmut K. |issue=Pt 1 |pmid=33038777 }}</ref>

It is a good [[Storage of wine|wine storage]] time−temperature marker,<ref>{{cite journal | last1 = Serra-Cayuela | first1 = A. | last2 = Jourdes | first2 = M. | last3 = Riu-Aumatell | first3 = M. | last4 = Buxaderas | first4 = S. | last5 = Teissedre | first5 = P.-L. | last6 = López-Tamames | first6 = E. | year = 2014 | title = Kinetics of Browning, Phenolics, and 5-Hydroxymethylfurfural in Commercial Sparkling Wines | journal = J. Agric. Food Chem. | volume = 62 | issue = 5| pages = 1159–1166 | doi = 10.1021/jf403281y | pmid = 24444020 }}</ref> especially in [[sweet wine]]s such as [[Madeira wine|Madeira]]<ref>{{cite journal | doi = 10.1016/j.foodres.2010.11.011 | volume=44 | title=Evolution of 5-hydroxymethylfurfural (HMF) and furfural (F) in fortified wines submitted to overheating conditions | year=2011 | journal=Food Research International | pages=71–76 | last1 = Pereira | first1 = V.| hdl=10400.14/7635 | hdl-access=free }}</ref> and those sweetened with grape concentrate [[arrope]].<ref>{{cite journal | doi = 10.1111/j.1365-2621.1948.tb16621.x | volume=13 | year=1948 | journal=Journal of Food Science | pages=264–269 | last1 = Amerine | first1 = Maynard A.| title=Hydroxymethylfurfural in California Wines | issue=3 | pmid=18870652 }}</ref>

[[File:Dictyophora indusiata Feb 2010.JPG|thumb|left|''[[Phallus indusiatus]]''. [[Cooktown, Queensland]], Australia. The fruiting body contains '''hydroxymethylfurfural''']]

HMF can be found in low amounts in [[honey]], fruit-[[juice]]s and [[Ultra-high-temperature processing|UHT]]-milk. Here, as well as in vinegars, jams, alcoholic products or biscuits, HMF can be used as an indicator for excess heat-treatment. For instance, fresh honey contains less than 15&nbsp;mg/kg—depending on pH-value and temperature and age,<ref name = Ruiz-Matute>{{cite journal | last1 = Ruiz-Matute | first1 = AI | last2 = Weiss | first2 = M | last3 = Sammataro | first3 = D | last4 = Finely | first4 = J | last5 = Sanz | first5 = ML | title = Carbohydrate composition of high-fructose corn syrups (HFCS) used for bee feeding: effect on honey composition | journal = [[Journal of Agricultural and Food Chemistry]] | volume = 58 | issue = 12 | pages = 7317–22 | year = 2010 | pmid = 20491475 | doi = 10.1021/jf100758x}}</ref> and the [[codex alimentarius| codex alimentarius standard]] requires that honey have less than 40&nbsp;mg/kg HMF to guarantee that the honey has not undergone heating during processing, except for tropical honeys which must be below 80&nbsp;mg/kg.<ref>{{cite journal | pmc = 5884753| pmid=29619623 | doi=10.1186/s13065-018-0408-3 | volume=12 | title=5-Hydroxymethylfurfural (HMF) levels in honey and other food products: effects on bees and human health | year=2018 | journal=Chem Cent J | page=35 | last1 = Shapla | first1 = UM | last2 = Solayman | first2 = M | last3 = Alam | first3 = N | last4 = Khalil | first4 = MI | last5 = Gan | first5 = SH| issue=1 | doi-access=free }}</ref>

Higher quantities of HMF are found naturally in coffee and dried fruit. Several types of roasted coffee contained between 300 – 2900&nbsp;mg/kg HMF.<ref>{{cite journal | last1 = Murkovic | first1 = M | last2 = Pichler | first2 = N | title = Analysis of 5-hydroxymethylfurfual in coffee, dried fruits and urine | journal = [[Molecular Nutrition & Food Research]] | volume = 50 | issue = 9 | pages = 842–6 | year = 2006 | pmid = 16917810 | doi = 10.1002/mnfr.200500262}}</ref> Dried plums were found to contain up to 2200&nbsp;mg/kg HMF. In dark beer 13.3&nbsp;mg/kg were found,<ref>{{cite journal | last1 = Husøy | first1 = T | last2 = Haugen | first2 = M | last3 = Murkovic | first3 = M | last4 = Jöbstl | first4 = D | last5 = Stølen | first5 = LH | last6 = Bjellaas | first6 = T | last7 = Rønningborg | first7 = C | last8 = Glatt | first8 = H | last9 = Alexander | first9 = J | title = Dietary exposure to 5-hydroxymethylfurfural from Norwegian food and correlations with urine metabolites of short-term exposure | journal = [[Food and Chemical Toxicology]] | volume = 46 | issue = 12 | pages = 3697–702 | year = 2008 | pmid = 18929614 | doi = 10.1016/j.fct.2008.09.048 }}</ref> bakery-products contained between 4.1 – 151&nbsp;mg/kg HMF.<ref>{{cite journal | last1 = Ramírez-Jiménez | first1 = A | title = Hydroxymethylfurfural and methylfurfural content of selected bakery products | journal = [[Food Research International]] | volume = 33 | page = 833 | year = 2000 | doi = 10.1016/S0963-9969(00)00102-2 | issue = 10| last2 = Garcı́a-Villanova | first2 = Belén | last3 = Guerra-Hernández | first3 = Eduardo }}</ref>

It can be found in [[glucose syrup]].

HMF can form in [[high-fructose corn syrup]] (HFCS), levels around 20&nbsp;mg/kg HMF were found, increasing during storage or heating.<ref name = Ruiz-Matute/> This is a problem for American [[beekeepers]] because they use HFCS as a source of sugar when there are not enough [[nectar]] sources to feed [[honeybees]], and HMF is toxic to them. Adding bases such as soda ash or potash to [[pH|neutralize]] the HFCS slows the formation of HMF.<ref name = Ruiz-Matute/>

Depending on production-technology and storage, levels in food vary considerably. To evaluate the contribution of a food to HMF intake, its consumption-pattern has to be considered. Coffee is the food that has a very high relevance in terms of levels of HMF and quantities consumed.

HMF is a natural component in heated food but usually present in low concentrations. The daily intake of HMF may underlie high variations due to individual consumption-patterns. It has been estimated that the intakes range between 4&nbsp;mg - 30&nbsp;mg per person per day, while an intake of up to 350&nbsp;mg can result from, e.g., beverages made from dried plums.<ref name=":0" /><ref name=":1">{{Cite journal |last1=Abraham |first1=Klaus |last2=Gürtler |first2=Rainer |last3=Berg |first3=Katharina |last4=Heinemeyer |first4=Gerhard |last5=Lampen |first5=Alfonso |last6=Appel |first6=Klaus E. |date=May 2011 |title=Toxicology and risk assessment of 5-Hydroxymethylfurfural in food |journal=Molecular Nutrition & Food Research |volume=55 |issue=5 |pages=667–678 |doi=10.1002/mnfr.201000564 |issn=1613-4133 |pmid=21462333}}</ref>{{Clear}}

== Biomedical ==

A major [[metabolite]] in humans is 5-hydroxymethyl-2-furoic acid (HMFA), also known as Sumiki's acid, which is excreted in urine.

HMF bind intracellular sickle hemoglobin (HbS). Preliminary ''[[in vivo]]'' studies using transgenic sickle mice showed that orally administered 5HMF inhibits the formation of sickled cells in the blood.<ref>{{cite journal | last1 = Abdulmalik | first1 = O | last2 = Safo | first2 = MK | last3 = Chen | first3 = Q | last4 = Yang | first4 = J | last5 = Brugnara | first5 = C | last6 = Ohene-Frempong | first6 = K | last7 = Abraham | first7 = DJ | last8 = Asakura | first8 = T | title = 5-hydroxymethyl-2-furfural modifies intracellular sickle haemoglobin and inhibits sickling of red blood cells | journal = British Journal of Haematology | volume = 128 | issue = 4 | pages = 552–61 | year = 2005 | pmid = 15686467 | doi = 10.1111/j.1365-2141.2004.05332.x| s2cid = 22342114 | doi-access = free }}</ref> Under the development code Aes-103, HMF has been considered for the treatment of [[sickle cell disease]].<ref>{{Cite web|date=2015-03-18|title=Aes-103 for Sickle Cell Disease|url=https://ncats.nih.gov/trnd/projects/complete/aes-103-sickle-cell|access-date=2022-01-20|website=National Center for Advancing Translational Sciences|language=en}}</ref>

Today, [[High-performance liquid chromatography|HPLC]] with UV-detection is the reference-method (e.g. DIN 10751–3). Classic methods for the quantification of HMF in food use [[Spectrophotometry|photometry]]. The method according to White is a differential UV-photometry with and without sodium bisulfite-reduction of HMF.<ref>{{cite journal |last1=White Jr. |first1=J. W. |title=Spectrophotometric method for hydroxymethylfurfural in honey |journal=Journal of the Association of Official Analytical Chemists |date=1979 |volume=62 |issue=3 |pages=509–514 |doi=10.1093/jaoac/62.3.509 |pmid=479072|doi-access=free }}</ref> Winkler photometric method is a colour-reaction using p-[[toluidine]] and [[barbituric acid]] ([[DIN]] 10751–1). Photometric test may be unspecific as they may detect also related substances, leading to higher results than HPLC-measurements. Test-kits for rapid analyses are also available (e.g. Reflectoquant HMF, Merck KGaA).<ref>{{cite journal | last1 = Schultheiss | first1 = J. | last2 = Jensen | first2 = D. | last3 = Galensa | first3 = R. | doi = 10.1016/S0021-9673(99)01086-9 | pmid = 10890522 | title = Determination of aldehydes in food by high-performance liquid chromatography with biosensor coupling and micromembrane suppressors | year = 2000 | volume = 880 | issue = 1–2 | pages = 233–42 | journal = [[Journal of Chromatography A]]}}</ref><ref>{{cite journal | last1 = Gaspar | first1 = Elvira M.S.M. | last2 = Lucena | first2 = Ana F.F. | title = Improved HPLC methodology for food control – furfurals and patulin as markers of quality | doi = 10.1016/j.foodchem.2008.11.097 | year = 2009 | page = 1576 | volume = 114 | journal = [[Food Chemistry (journal)|Food Chemistry]] | issue = 4}}</ref>

== Other ==

HMF is an intermediate in the titration of hexoses in the [[Molisch's test]]. In the related [[Bial's test]] for pentoses, the hydroxymethylfurfural from hexoses may give a muddy-brown or gray solution, but this is easily distinguishable from the green color of pentoses.

Acetoxymethyl furfural (AMF) is also bio-derived green platform chemicals as an alternative to HMF.<ref>{{cite journal|last1=Kang|first1=Eun-Sil|last2=Hong|first2=Yeon-Woo|last3=Chae|first3=Da Won|last4=Kim|first4=Bora|last5=Kim|first5=Baekjin|last6=Kim|first6=Yong Jin|last7=Cho|first7=Jin Ku|last8=Kim|first8=Young Gyu|title=From Lignocellulosic Biomass to Furans via 5-Acetoxymethylfurfural as an Alternative to 5-Hydroxymethylfurfural|journal=ChemSusChem|date=13 April 2015|volume=8|issue=7|pages=1179–1188|doi=10.1002/cssc.201403252|pmid=25619448|issn=1864-564X}}</ref>

==References==

{{reflist|30em}}

[[Category:Hydroxymethyl compounds]]

[[Category:Furfurals]]