Food Analysis - Metrohm
Food analysisQuality control in the food and beverage industry
02Metrohm. is the global market leader in titration is the only company to offer a complete range of ion analysis equipment – titration,voltammetry and ion chromatography is a Swiss company and manufactures exclusively in Switzerland grants a 3-year instrument warranty and a 10-year warranty on chemical suppressors forion chromatography provides you with unparalleled application expertise offers you more than 1300 applications free of charge supports you with expert service through local representatives and regional support centers is not listed on the stock exchange, but is owned by a foundation. gives the interests of customers and employees priority over maximizing profit
Metrohm – customized analysis for the food andbeverage industryThe law sets high standardsThe food industry is subject to particularly strict regulations on the quality and safety of its products. This is notwithout reason: If contaminated food reaches the retailmarket, the consequences can be serious – and not justfor the consumers.Regulatory complianceIn order to guarantee the industry’s strict quality andsafety standards, reliable instruments and methods areneeded in the laboratory. These instruments and methods must meet highest standards. Regulatory complianceis the catchword here.Count on our supportAs a leading manufacturer of instruments for chemicalanalysis, we are quite aware of these challenges youface. For this reason, we offer you not just the mostadvanced equipment, but rather complete solutions forthe particular tasks at hand. Your partners at Metrohmare experienced professionals who develop customizedapplications for you and support you in every aspect ofregulatory compliance with our expert service.On the following pages, discover the solutions Metrohmoffers the food industry in general and you in particular,to ensure the quality and safety of your products.Challenge us!Metrohm instruments comply with numerous officialstandards, including the FDA regulation Title 21 CFRPart 11.03
Methods available from Metrohm for the foodindustry04The following table is organized according to productareas and lists relevant parameters that can be determined using methods developed by Metrohm. Moreover,you can see which standards these methods fulfill. If youcannot find your sample matrix or a parameter that isSampleParametersfor titrationMeat products, meatextracts, bouillonpreparations, spices,soups, saucesChloride (NaCl)Kjehldahl nitrogenSulfurous acidTable salt, spices,pickling salt, herbsand aromatic saltsChloride (NaCl)Total iodineFluorideTricalciumphosphateNitriteCanned fruit,vegetables and mushrooms, dried fruitand vegetablesOxalic acidTotal sulfurous acidAcid contentSalt contentSweeteners, gellingMethoxy and ethoxyand thickening agents groupsCyclamateSaccharinCoffee, cocoa,chocolate, teapH value and acidityAsh alkalinityChlorideDirect reducingsugarsKjehldahl nitrogenFree fatty acidsIodine valueSaponification valueBeer, vinegar, spiritsand winepH value and totalacidCO2 contentAscorbic acidFree and totalsulfurous acidVolatile acidsAsh alkalinityChlorideSulfateTotal ester contentimportant for you, please contact your local Metrohmrepresentative. We are continuously expanding our rangeof applications and will gladly assist you in solving yourspecific analytical problem.ParametersParametersParametersfor ion chromatographyfor voltammetry for stabilitymeasurementPb in fish- Anions: nitrite, nitrate(AOAC 972-24)(DIN EN 12014-4:2005), chloride,phosphate- Polyphosphates- Organic acids- Cations: Na , NH4 , K , Ca2 ,Mg2 ,- Biogenic amines in fish- Monosaccharides anddisaccharides- Sugar alcoholsIodide, iodate- Anions: sulfate, sulfite, bromide,iodide, chloride, iodate, fluoride,phosphate, molybdate- Polyphosphates- Organic acids- Cations: Na , K Sn, other heavy- Anions: phosphite, nitrite, nitratemetals(DIN EN 12014-2:1997), chloride,phosphate, sulfate, perchlorate- Organic acids- Cations: K , Mg2 - Monosaccharides anddisaccharides- Anions: fluoride, chloride, bromide,nitrate, phosphate, sulfate- Organic acids- Cations: Na , K , NH4 , Ca2 , Mg2 ,Fe2 - Mono-, di-, oligo- andpolysaccharides- Sugar alcohols- Glycerol- Sucralose, saccharin, cyclamate- Anions: fluoride- Organic acids- Cations: Na , K , Ca2 , Mg2 - Monosaccharides anddisaccharides in instant coffee(ISO 11292)- Arabinose, fructose, galactose,glucose, mannose, sucrose, xylose,maltose, lactose- Sugar alcohols- Glycerol- Caffeine- Anions: fluoride, chlorite, chloride,Heavy metalsbromide, nitrate, sulfite, sulfate,(Cd, Pb, Cu, .)phosphate, oxalate(Swiss Fruit Assn.)- Organic acids- Cations: Na , K , NH4 , Ca2 , Mg2 - Transition metals: Cu2 , Zn2 , Fe2 ,Mn2 - Biogenic amines- Monosaccharides, disaccharidesand oligosaccharides- Sugar alcohols- GlycolsParametersfor ProcessLabChloride (NaCl)Chloride (NaCl)Total iodineFluorideTricalcium phosphateNitriteChloride (NaCl)pH value and acidityAsh alkalinityChlorideDirect reducing sugarsFree fatty acidsIodine valueSaponification valuepH value and total acidCO2 contentAscorbic acidFree and total sulfurousacidVolatile acidsChlorideSulfateTotal ester content
SampleParametersfor titrationFruit and vegetablejuices, fruit nectarsand jamspH value andtitratable total acidAscorbic acidSulfurous acid(sulfite)ChlorideTotal phosphorousSulfateCations: Ca2 , Mg2 ,K Ash alkalinityFormol numberReducing sugarspH value andtitratable acidChlorideCalciumAscorbic acidKjehldahl nitrogenMilk and dairyproductsParametersParametersfor ion chromatographyfor stabilitymeasurement- Anions: chloride, phosphate,Ascorbic acidsulfate, nitrite, phosphitePb (AOAC 979-17)- Organic acidsFumaric acid- Cations: Na , K , Ca2 , Mg2 (AOAC 968-16)Saccharin- Monosaccharides and(SLB 41-2.5)disaccharidesParameters forvoltammetryPb (AOAC 974-13;AOAC 979-17)NutsFruit and vegetables- Anions: iodide, chloride,phosphate, sulfate, nitrate, nitrite,thiocyanate, perchlorate, cyanurate- Organic acids- Cations: Na , NH4 , K , Ca2 , Mg2 - Monosaccharides anddisaccharides- Choline- MelamineOxalic acidTotal sulfurous acidChlorideZn (ISO 6636-1)pH value and titratabletotal acidAscorbic acid(e.g., oranges)Cd, Pb (AOAC983-23)Animal and plant fats Acid value and freeand oilsfatty acidsHydroxyl numberIodine valuePeroxide valueSaponification valueOxidationstability (AOCSCd 1b-92,ISO 6886)- Anions: phosphate, bromate- Cations: Ca2 , Mg2 Crackers, bakedgoodsInstant noodlesOxidationstabilityOxidationstability- Monosaccharides anddisaccharidesTable and mineralpH value and acidwater, drinking water capacitiesCa2 , Mg2 and totalhardnessChloride, sulfateSulfides/hydrogensulfideTotal and residualchlorinePermanganate indexCO2 contentOxygen contentaccording to WinklerRinsing, cleaning anddisinfection processesin the beverageindustrypH value and titratabletotal acidAscorbic acidSulfurous acid (sulfite)ChlorideTotal phosphorousSulfateCalcium and magnesiumPotassiumFormol numberReducing sugarsOxidationstabilityGrainsSoft drinksParametersfor ProcessLabCitric acid/citratePhosphoric acid(cola drinks)PotassiumTotal phosphorusU (DIN 38406-17),CN– (samplepreparationaccording toDIN 38405-13)- Anions: fluoride, chloride, nitrite,bromide, nitrate, phosphate,sulfate, iodide, silicate, carbonate,chromateASTM D 4327-03EPA 300.1ISO 10304-1:2007- Oxyhalides: bromate, chlorite,chlorateISO 10304-4ASTM D 6581-08- Cations: Na , NH4 , K , Ca2 , Mg2 ISO 14911:1998- Phenols- Anions: chloride, nitrate,phosphate- Organic acids- Cations: Na , NH4 , K , Ca2 , Mg2 - Monosaccharides anddisaccharides- Sugar alcohols- Phenylalanine, aspartame, caffeine- GlucoronolactoneHydroxyl numberIodine valuePeroxide valueSaponification valueNative olive oils:Acid valueFree fatty acidsWater contentConductivityAlkalinitypH value and acidcapacitiesCa2 , Mg2 and totalhardnessChloride, sulfateSulfides/hydrogen sulfideTotal and residualchlorinePermanganate indexCO2 contentAcid contentIngredients in rinsingand cleaning solutions,acids, such as peraceticacid, pH value andconductivity05
pH measurement06pH measurement is one of the most important parameters in the quality control of foodstuffs. pH providesinformation on the quality of natural products such ascitrus fruits, juices or dairy products for example.Furthermore, pH is an important parameter in the use ofacidity regulators as preservatives.The requirements of the pH electrode that is used formeasurement are just as varied as the many foods to beanalyzed. The selection of a diaphragm that is appropriate for the sample is especially important since otherwisethe electrolyte bridge can quickly become blocked by thesample, which leads to erroneous measurements.The following table shows examples of which Metrohmelectrode is suitable for pH determination in which foods.SampleDrinking waterGeneral, e.g., wine andspirits, fruit andvegetable juices, cerealsconfectioneriesProtein-containing samples(e.g., dairy products)Penetration measurements(e.g., dough, cheese, meat)Surfaces, small samplevolumesElectrode(Order Number)Properties Precise measurements and very rapid response evenin low-conductivity, weakly buffered solutions contamination-insensitive fixed ground-jointAquatrode plusdiaphragm(6.0257.000) Maintenance-free reference electrolyte, variableouter electrolyte for special applications Optimized length for sample changer applications Universal useUnitrode Short response time after temperature changes(6.0258.600) Contamination-insensitive fixed ground-jointdiaphragm Especially for highly contaminated and proteinPorotrodecontaining or viscous samples(6.0235.200) Low maintenance capillary diaphragm Polymer electrolyte for uniform electrolyte flow Robust electrode tip for measurements in semisolidSpearheadsamples(6.0226.100) Maintenance-free reference electrolyte Easy-to-clean pinhole diaphragmFlat membrane electrode For measurements on surfaces or in very small(6.0256.100)sample volumes
07Rugged, reliable and easy to use: pH meters fromMetrohmpH determinations with the 826 pH mobile and827 pH lab metersWhether you are performing routine pH determinationsin the laboratory or out in the field – with Metrohm pHmeters you never have to do without GLP: three-pointcalibration, automatic buffer recognition, temperaturecompensation, sample identification, GLP-compliantprintout and a large memory for storing measurementresults – pH meters from Metrohm offer all of thesefeatures at a very attractive price.pH, chloride, fluoride and ammonium determinations with the 780 pH Meter or 781 pH/Ion MeterThe 780 pH Meter is the top choice if you need to knoweverything exactly: nine-point calibration, stirrer control,electrode test for glass pH electrodes, method memoryand RS232 interface.Besides measuring pH, the 781 pH/Ion Meter can alsodetermine the concentration of individual ions (e.g., Cl–,F– and NH4 ) by either direct measurement or fully automatic standard addition.
Titration08Benefit from the know-how of the market leaderMetrohm is the leading manufacturer in the field of titration. Sixty years of experience and the most comprehensive and innovative program on the market are proof ofour strength. Our collection of potentiometric applications that is available to you is huge. Benefit from morethan 150 proven titration applications from the foodindustry sector that we have prepared based on thefollowing publications: Deutsche Einheitsverfahren zur Wasser-, Abwasserand Schlammuntersuchung (German StandardMethods for the Examination of Water, Wastewaterand Sludge) Official Methods of Analysis of the Association ofOfficial Analytical Chemists (AOAC, U.S.A.) Schweizerisches Lebensmittelbuch (SLMB; SwissManual on Food Safety) U.S. Environmental Protection Agency (EPA)An overview of some application examplesTotal sulfurous acid in dried fruitsIodine value of edible fats and oilsSulfurous acid in winepH value of beerTotal hardness of drinking waterSalt (NaCl) in meat and meat productsTotal acid in nonalcoholic beveragesAcidity of roasted coffee beansOxalic acid in fruit and canned fruitAscorbic acid (vitamin C)SLMB 553.1AOAC 28.023AOAC 940.20AOAC 945.10EPA 130.2AOAC 935.47AOAC 950.15AOAC 920.92AOAC 974.24AOAC 967.21Electrodes for titrationThe correct electrode for every applicationChoosing the right electrode is crucial for successful titration. For combined electrodes, the correct diaphragmmust be chosen because otherwise the electrolyte bridgecan become blocked. The response behavior of the electrode is also important, in particular if the titration is tobe carried out to a defined endpoint.This is the case for many applications in the food industry. If the electrode reacts too slowly, the solution will beover-titrated and incorrect results are obtained. Metrohmoffers an appropriate electrode for every need. The following table shows which Metrohm electrode is suitablefor which application.Area of applicationGeneralAcid content of alcoholic beveragesCarbonate hardness, acid capacity of water, p and m valuesDetermination of Ca2 , Mg2 (complexometric)Permanganate indexTitratable total acid in dairy productsCalcium content in dairy productsKjehldahl nitrogen in milkVitamin C in fruit juiceFormol numberFree fatty acids, hydroxyl number in oilsIodine value, peroxide valueWater determination according to Karl FischerGeneral chloride, table salt content in foodMetrohm electrodeEcotrode plusUnitrodeAquatrode plusCa2 ISEPt TitrodePorotrodeCu2 ISEEcotrode GelDouble Pt-sheet electrodeUnitrodeSolvotrodePt TitrodeDouble Pt-wire electrodeAg TitrodeAdditional examples and practical tips on using Metrohmelectrodes are given in the leaflets «Electrodes forTitration» and «Electrodes for pH Measurement». Thesecan be downloaded for free at 30.100
Titration with Metrohm: Solutions for every needand budgetWith the 848 Food/Beverage Titrino plus, the 862 Food/Beverage Compact Titrosampler and the 905 FoodTitrando, Metrohm offers you three complete titrationpackages. No matter which package you choose, simpleand reliable work is guaranteed:848 Food/Beverage Titrino plus – the economically pricedtitrator for routine analysis in the food laboratory. This all-inclusive package also comprises an USB stick with 100 methodsstored for the most important applications in food analysis. intelligent exchange or dosing units ensure the useof the correct titration solution and permit their monitoring all important titration parameters are stored with themethods; this means that even unskilled users quicklyobtain reliable results GLP-compliant data output either on a printer or bydigital archiving862 Compact Titrosampler – the automatic titration stationfor higher sample throughput. With the 862 Food/BeverageCompact Titrosampler and the 862 Salt Compact Titrosampler,Metrohm offers two all-inclusive packages that come witheverything from the electrode and sample beaker to the methodtemplates for the professional food analysis.905 Food Titrando – the high-end titrator for the highestdemands. Frequently used methods can be started with thepush of a single button. Complete traceability of measuringresults, central data management through the client-serveroption, method templates, individual method development,possibility for complete automation and much more.09
Thermometric titration: the ideal complement topotentiometric titration10Thermometric titration is a highly versatile determinationmethod and is the ideal complement to potentiometrictitration. In principle, the method is suitable for everyreaction that creates a sufficiently large temperaturechange in the sample solution. This method is particularly suitable in applications for which:This principle is the basis of thermometric titration. In athermometric titration, reagent solution (titrant) is continually added until the endpoint is reached. The endpoint is seen as a break in the titration curve if the temperature is plotted as a function of the volume of addedtitrant. an appropriate potentiometric sensor is not available an appropriate reference electrode is not available the sample matrix would compromise or even destroythe electrode an appropriate solvent for potentiometry is not availableThermometric titration – the principleEvery chemical reaction is associated with a change inreaction enthalpy. This results in either an increase (exothermic reaction) or a decrease (endothermic reaction) ofthe sample solution temperature.859 TitrothermThe 859 Titrotherm combines innovative, glass-freesensor technology and the unrivalled titration know-howof Metrohm. The instrument is automatically recognizedwhen connected to a computer and hence, must not bemanually configured. The software determines the endpoints based on the first and second derivatives of thetitration curve; with additional optimization parameters,reproducibility can be further increased.Advantage of thermometric titration: The temperature sensor (thermoprobe) of the 859 Titrotherm is almost maintenancefree and can be used immediately without prior conditioning.
11Application examplesUnsaturated fatty acids in edible oilDetermination of the content of unsaturated fatty acidsin edible oil is based on the titration of weak acids innonaqueous solutions with a dilute solution of a strongbase in alcohol. Problems that occur when performingpotentiometric titrations on samples with low free fattyacid contents can be avoided with thermometric titrations. Thermometric titration is simple and employs acatalyzed indicator reaction.Determination of sodium content in foodThe sodium content of foods is usually determined indirectly through a precipitation reaction with silver nitrate.For this, it is assumed that the chloride and sodium ionsare in a 1:1 molar ratio. However, this is not true if otherchemical substances such as sodium benzoate and monosodium glutamate or compounds such as potassiumchloride that contain sodium chloride are present in thematrix. This is often the case for sodium-containing foods.Established methods for the direct determination of sodium such as AAS or ICP/MS have the disadvantage thatthe required instruments are very expensive. Thermometric titration is a cost-effective and easy-to-performalternative. To carry out this method, the sample is firsthomogenized. Afterwards, the sample solution is titratedwith an aluminum nitrate solution containing an excessof potassium ions in the presence of NH4HF2 at pH 3.Insoluble NaK2AlF6 is formed in an exothermic reaction.
Karl Fischer titration12Determination of water content in food,beverages, tobacco and pet foodThe water content largely determines the quality andshelf life of many food products. The amount of water infood can be easily determined by means of Karl Fischertitration.Water exists in food in different forms. They range fromclearly defined forms (for example, as in sucrose andalcoholic beverages) to those in complex cellular structures (for example, as in dry fruits) in which the water isbound to the surface as well as between particles.Moreover, water can also be trapped within the cells andmust be released through appropriate sample preparation before the measurement.Simple sample preparationFor the latter types of samples, the use of a high frequency homogenizer is recommended. Homogenizingreleases the water and at the same time, stirs the sample.Because the sample preparation takes place directly inthe titration vessel, no additional water is absorbed andthe water content determined is not biased.In most food, water is not distributed homogeneouslythroughout the material. The sample to be measuredmust be taken so that it statistically represents the average. To this end, a larger amount of sample (if necessary)is comminuted and homogenized and the water contentdetermined in an aliquot.When to
Metrohm – customized analysis for the food and beverage industry Count on our support 03 As a leading manufacturer of instruments for chemical analysis, we are quite aware of these challenges you face. For this reason, we offer you not just the most advanced equipment, but rather complete solutions for the particular tasks at hand.
Analysis of Anions and Cations in Tomato Products Branch . Ultrapure water, resistivity 18 MΩ·cm (25 C) Metrohm Custom Anion Mix 3, 100 ppm fluoride, . ammonium, potassium , magnesium, calcium; Metrohm USA ERA-IC1230 Metrohm Individual Anion and Cation Standards, 1000 ppm o Chloride, Metrohm USA ERA-IC1002 o Sodium, Metrohm .
Metrohm offers a large range of pH and ion-selective electrodes. Please find an overview of our electrode program under www.metrohm.com The package of the 780 pH Meter and 781 pH/Ion Meter contain the 6.0258.600 Unitrode pH electrode with integrated Pt1000 temperature sensor. Switch on and measure
Metrohm Germany The analytical challenges of environmental analysis increase in diffi culty from year to year. As well as analysis of particularly toxic types of metals such as chromium(VI), highly diverse and partially persis-tent organic fl uorine compounds (e.g., trifl uoroace-tic acid) are presently in focus. The analysis of toxic
Metrohm – customized water analysis Harmful substances in water Water is the source and basis of all life. It is essential for metabolism and is our most important foodstuff. As a solvent and transporting agent it carries not only the vital minerals and nutrients, but also, increasingly, harmful
benefits that the ICON Analyzer from Metrohm Process Analytics provides. The new ICON Analyzer was devel-oped specifically for the near-continuous analysis of a large number of parameters critical for water quality. Very easy to use: Just connect the power, sample, and reagent lines and the ICON Analyzer is fully operational.
Types of food environments Community food environment Geographic food access, which refers to the location and accessibility of food outlets Consumer food environment Food availability, food affordability, food quality, and other aspects influencing food choices in retail outlets Organizational food environment Access to food in settings
Internet under www.metrohm.com. Fig. 1: 781 pH/Ion Meter connected to 801Magnetic Stirrer 1.1 Instrument description Both instrument versions, the 781 pH/Ion Meter and the 780 pH Meter, are used for measuring pH, temperature and potential reliably and at high resolution. The 781 pH/Ion Meter differs from the 780 pH Meter by
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