1 SYMPOSIUM ON FOOD CHEMISTRY AND QUALITY ASSURANCE.

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SYMPOSIUM ON FOOD CHEMISTRY AND QUALITY

ASSURANCE

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Alan Richards

Head of Scientific ServicesHead of Scientific Services

Public Analyst (2m population)Public Analyst (2m population)

Official Agricultural AnalystOfficial Agricultural Analyst

President Association Public AnalystsPresident Association Public Analysts

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Summary History of Food Adulteration in UKHistory of Food Adulteration in UK Public Analyst Links to EnforcementPublic Analyst Links to Enforcement Legal Qualification (MChemA)Legal Qualification (MChemA) MChemA ExaminationMChemA Examination Certificates of AnalysisCertificates of Analysis EU Methods and UK AnalysisEU Methods and UK Analysis Test MethodsTest Methods Food ComplaintsFood Complaints Other work of Public AnalystsOther work of Public Analysts

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UNITED KINGDOM

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DURHAM

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HISTORY OF FOOD ADULTERATION

1200 AD – KING HENRY II “GARBLE”1200 AD – KING HENRY II “GARBLE”

1700 AD – STEADY INCREASE1700 AD – STEADY INCREASE

1800 AD – INDUSTRIAL REVOLUTION1800 AD – INDUSTRIAL REVOLUTION

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In 1820 A TREATISE ON

ADULTERATIONS OF FOOD,AND CULINARY POISONS.

 EXHIBITING

The Fraudulent Sophistications of 

BREAD, BEER, WINE, SPIRITOUS LIQUORS, TEA, COFFEE, CREAM, CONFECTIONERY, VINEGAR, MUSTARD, PEPPER, CHEESE, OLIVE

OIL, PICKLES,AND OTHER ARTICLES EMPLOYED IN DOMESTIC ECONOMY.

ANDMETHODS OF DETECTING THEM.

 By Fredrick Accum,

 OPERATIVE CHEMIST, AND MEMBER OF THE PRINCIPAL ACADEMIES AND SOCIETIES OF ARTS AND SCIENCES

IN EUROPE.Philadelphia:

PRINTED AND PUBLISHED BY AB'M SMALL1820.

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Frederick Accum

http://www.gutenberg.org/etext/19031

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1851 - 54 ARTHUR HILL HASSALLARTHUR HILL HASSALL

Purchased and analysed 2500 articles of food Purchased and analysed 2500 articles of food and produced reports in the medical journal and produced reports in the medical journal The Lancet identifying many examples of The Lancet identifying many examples of adulteration of foods.adulteration of foods.

Information Link:Information Link:http://www.rsc.org/Education/EiC/issues/2005Mar/Thefightagainstfoodadulteration.asp

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Origin of UK Food Law

            18601860 ADULTERATION OF FOOD AND DRINKS ACTADULTERATION OF FOOD AND DRINKS ACT

              18721872 ADULTERATION OF FOOD AND DRUGS ACTADULTERATION OF FOOD AND DRUGS ACT

              18751875 SALE OF FOOD AND DRUGS ACTSALE OF FOOD AND DRUGS ACT

              18991899 SALE OF FOOD AND DRUGS ACTSALE OF FOOD AND DRUGS ACT

              19281928 FOOD AND DRUGS ADULTERATION ACTFOOD AND DRUGS ADULTERATION ACT

              19381938 FOOD AND DRUGS ACTFOOD AND DRUGS ACT

              19551955 FOOD AND DRUGS ACTFOOD AND DRUGS ACT

              19801980 FOOD ACTFOOD ACT

              19901990 FOOD SAFETY ACTFOOD SAFETY ACT

19991999 FOOD STANDARDS AGENCYFOOD STANDARDS AGENCY

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Modern Public Analysts

Public Analyst

Industry

Food Standards

Agency

Government Chemist

Environmental Health

Consumers

Trading Standards

Central Science Lab

English Law Courts

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QUOTATION ““The duties of the Public Analyst are daily The duties of the Public Analyst are daily

increasing in complexity and difficulty. increasing in complexity and difficulty. Higher qualifications than formerly are Higher qualifications than formerly are required of him, owing not only to the required of him, owing not only to the general advance in science as applied to general advance in science as applied to the analysis of food, but also the exacting the analysis of food, but also the exacting character of the numerous regulations of character of the numerous regulations of government departments concerned. . . .government departments concerned. . . . “ “

September 1923September 1923

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Mastership in Chemical Analysis

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Food Safety Act Certificate

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The MChemA Examination

Theory of analytical instrumentation, Theory of analytical instrumentation, QA and statistics, QA and statistics, Methods of testing, Methods of testing, Laws relating to food, water and animal Laws relating to food, water and animal

feedsfeeds Practical application of skillsPractical application of skills Ability to write certificates of analysisAbility to write certificates of analysis

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MChemA Questions Day 1Day 1

Theory of Analytical Chemistry, 3 hours,Theory of Analytical Chemistry, 3 hours, Methods of analysis food, drugs & water 3 hoursMethods of analysis food, drugs & water 3 hours

Day 2 Day 2

law related to food, drugs and waterlaw related to food, drugs and water, lab administration, lab administration identify the six unknown substances using the microscopeidentify the six unknown substances using the microscope

Day 3, 4 and 5Day 3, 4 and 5 Practical Demonstration of SkillsPractical Demonstration of Skills

http://www.rsc.org/Education/Qualifications/MChemA/Index.asp

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Certificates of Analysis

Food Safety ActFood Safety Act

The FACTSThe FACTS

The STANDARDThe STANDARD

The INTERPRETATIONThe INTERPRETATION

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Certificates of Analysis

Food Complaint CertificateFood Complaint Certificate Full HistoryFull History PhotographsPhotographs Results of AnalysisResults of Analysis InterpretationInterpretation None Technical ReportNone Technical Report

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Other Certificates

Agriculture Act CertificatesAgriculture Act Certificates

Statements of WitnessStatements of Witness

UKAS UKAS

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Official Food Labs

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Other Work

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Other Work

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UK Food Laws Pre 1980 – mostly set by UKPre 1980 – mostly set by UK EU InfluenceEU Influence EU Methods of AnalysisEU Methods of Analysis

Contaminants in Food Regulation 2007Contaminants in Food Regulation 2007 Commission Regulation (EC) No 1881/2006Commission Regulation (EC) No 1881/2006

of 19 December 2006of 19 December 2006 Commission Directive Commission Directive 2001/22/EC2001/22/EC

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Commission Directive 2001/22/EC

            Specific methods for the determination of lead, cadmium and mercury Specific methods for the determination of lead, cadmium and mercury contents are not prescribed.contents are not prescribed.

            Laboratories shall use a validated method that fulfils the performance Laboratories shall use a validated method that fulfils the performance criteria indicated in Table 3.criteria indicated in Table 3.

            Where possible, the validation shall include a certified reference material in Where possible, the validation shall include a certified reference material in the collaborative trial test materials.the collaborative trial test materials.

            LOD - No more than one tenth of the value of the specification in LOD - No more than one tenth of the value of the specification in Regulation (EC) No 466/2001, except if the value of the specification for lead is less Regulation (EC) No 466/2001, except if the value of the specification for lead is less

than 0,1 mg/kg. For the latter, no more than one fifth of the value of the specificationthan 0,1 mg/kg. For the latter, no more than one fifth of the value of the specification             LOQ - No more than one fifth of the value of the specification in Regulation LOQ - No more than one fifth of the value of the specification in Regulation

(EC) No 466/2001, except if the value of the specification for lead is less than 0,1 (EC) No 466/2001, except if the value of the specification for lead is less than 0,1 mg/kg. For the latter, no more than two fifths of the value of the specification.mg/kg. For the latter, no more than two fifths of the value of the specification.

            Precision HORRATPrecision HORRATrr or HORRAT or HORRATRR values of less than 1,5 in the validation values of less than 1,5 in the validation collaborative trial collaborative trial

            Recovery 80-120 % Recovery 80-120 %

Specificity - Free from matrix or spectral interferencesSpecificity - Free from matrix or spectral interferences

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UK and EU LawsWhen searching for UK regulations I need the date of the regulation and When searching for UK regulations I need the date of the regulation and

the statutory instrument (SI) number. All current regulations are the statutory instrument (SI) number. All current regulations are available on the internet on the website:available on the internet on the website:

http://www.opsi.gov.uk/  EC regulations can be found on the website:EC regulations can be found on the website:

http://eur-lex.europa.eu/en/index.htm   The public analyst website offers a list of current regulations on their The public analyst website offers a list of current regulations on their

website at:website at:  

http://www.publicanalyst.com/

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Sampling

Formal Sampling – passing onFormal Sampling – passing on

Informal SamplingInformal Sampling

ComplaintsComplaints

Regulation samplingRegulation sampling

ProjectsProjects

SurveillanceSurveillance

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Glass Contamination

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Fibres

Human Hair Mouse Hair

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Faecal Contamination

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Moulds

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Infestation

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Authenticity

Cod Haddock

SalmonColey

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Modes of AdulterationModes of Adulteration

Mislabelling of age Mislabelling of age

‘Stretching’ with neutral spirit (cereal or non–cereal derived)

‘Stretching’ with neutral spirit (cereal or non–cereal derived)

Geographic mislabelling Geographic mislabelling

Addition of flavourings Addition of flavourings

Addition of sweetening Addition of sweetening

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MethanolPropanolIsobutanol2-methyl-1-butanolIsoamyl alcohol

Ethyl acetateIsoamyl acetate

MethanolPropanolIsobutanol2-methyl-1-butanolIsoamyl alcohol

Ethyl acetateIsoamyl acetate

polarpolarpolarpolarpolar

polar ?polar ?

polarpolarpolarpolarpolar

polar ?polar ?

6597

108130130

77142

6597

108130130

77142

9 – 8260 – 1330150 – 620

1 – 3600 – 770

44 – 5002 - 25

9 – 8260 – 1330150 – 620

1 – 3600 – 770

44 – 5002 - 25

PolarityPolarityCompoundCompound BP (°C)BP (°C) Concentration rangeConcentration range

Chromatographic Analysis of Distilled Spirits

Chromatographic Analysis of Distilled Spirits

Major Volatile Congeners (Mostly alcohols and esters)Major Volatile Congeners (Mostly alcohols and esters)

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Modes of AdulterationModes of Adulteration

min2 4 6 8 10 12 14 16 18

pA

15

20

25

30

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Ace

tald

ehyd

e

Eth

yl A

ceta

teA

ceta

l

Met

han

ol

n-P

ropa

nol is

o-B

utan

ol

iso-

Am

yl A

ceta

te

n-B

utan

ol

2-M

ethy

l-1-B

uta

nol

3-M

ethy

l-1-

But

anol

n-P

enta

nol

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min10 15 20 25

mAU

75

80

Gal

lic A

cid

HM

F

Syr

ingi

c A

cid

Van

illin Syr

inga

ldeh

yde

Sco

pole

tin

Con

ifera

ldeh

yde

Sin

apal

deh

yde

min10 15 20 25

mAU

0

5

10

15

20

25

30

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Signal=260nm

Van

illic

Aci

d

Ella

gic

Aci

d

79

78

77

76

Signal=280nm+340nm

Cask ExtractivesCask Extractives

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Stable isotope analysisin food authentication

Simon Kelly1 & Alison Bateman2

1 Institute of Food Research, Norwich, UK, NR4 7UA ([email protected])2 University of East Anglia, Norwich, UK, NR4 7JT

Detecting the substitution of Organic crops with conventional produce

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Stable Isotopes of NitrogenStable Isotopes of Nitrogen

-

--

- --

P 7N 7

- -

--

- --

P 7N 8

‘light’ isotope ‘heavy’ isotope

14N7 15N7

99.63 % 0.37 %

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Tomatoes – normal distn

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

-10 -8 -6 -4 -2 0 2 4 6 8 10 12 14 16 18 20d15N(‰)air

Pro

bab

ilit

y

Conventional

Organic

n=43Mean = -0.1n-1 = 2.1

n=61Mean = +8.1 n-1 = 3.2

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

-10 -8 -6 -4 -2 0 2 4 6 8 10 12 14 16 18 20d15N(‰)air

Pro

bab

ilit

y

Conventional

Organic

n=43Mean = -0.1n-1 = 2.1

n=61Mean = +8.1 n-1 = 3.2

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Tomato Data - 3-D Scatter Plot for variables d15N‰, Mn (ppm), Cu (ppm) & Rb (ppm)

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A METHOD FOR THE SIMULTANEOUS

DETERMINATION OF SWEETENERS IN FOODS

Steve AppletonSteve Appleton Durham Scientific ServicesDurham Scientific Services

[email protected]@durham.gov.uk

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Evaporative Light Scattering Detector (ELSD)

Gaining popularity as a universal detector.Gaining popularity as a universal detector.

Simple three step processSimple three step process Nebulisation – column effluent forms a Nebulisation – column effluent forms a

dispersion of dropletsdispersion of droplets Evaporation – mobile phase is evaporated, Evaporation – mobile phase is evaporated,

leaving a fine mist of dried sample.leaving a fine mist of dried sample. Detection – laser light scattered by sample Detection – laser light scattered by sample

particles is detected, generating an particles is detected, generating an electrical signal.electrical signal.

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Evaporative Light Scattering Detector (ELSD)

Pro Pro since all particles scatter light, all since all particles scatter light, all

sample components are detected, sample components are detected, regardless of their structure or optical regardless of their structure or optical properties.properties.

Con Con method limitations as it can only be method limitations as it can only be

used with volatile mobile phases and used with volatile mobile phases and mobile phase modifiers mobile phase modifiers

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ELSD

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ELSD plus UV

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Elisa and DNA ProteinProtein

Heat labileHeat labile Cross reactivityCross reactivity Batch variationBatch variation

DNADNA Cooked foodsCooked foods SpecificSpecific Simplified “lab on a chip”Simplified “lab on a chip”

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Lab on a Chip

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DNA Analysis

ApplicationsApplications Fish & meat speciationFish & meat speciation Basmati rice authenticityBasmati rice authenticity Detection of bushmeatDetection of bushmeat GMO testingGMO testing Fruit juicesFruit juices Durum wheatDurum wheat

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Fish Speciation

Method uses PCR-RFLPMethod uses PCR-RFLP A region of a specific gene is amplified A region of a specific gene is amplified

by PCR using universal primersby PCR using universal primers Produces a single PCR product of the Produces a single PCR product of the

same size from all samplessame size from all samples Can be done on raw, cooked and some Can be done on raw, cooked and some

canned fish (not tuna)canned fish (not tuna) No need for a reference specimenNo need for a reference specimen

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DNA ResultsFish Species 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350

Atlantic cod

Pacific cod

Alaskan Pollack

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Reminder

A A WRONGWRONG RESULT RESULT

IS WORSEIS WORSE

THAN NO RESULT AT ALL !THAN NO RESULT AT ALL !

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THANK YOU