SYMPOSIUM ON FOOD
CHEMISTRY AND
QUALITY ASSURANCE
1
Alan Richards
Head of Scientific Services
Public Analyst (2m population)
Official Agricultural Analyst
President Association Public Analysts
2
Summary









History of Food Adulteration in UK
Public Analyst Links to Enforcement
Legal Qualification (MChemA)
MChemA Examination
Certificates of Analysis
EU Methods and UK Analysis
Test Methods
Food Complaints
Other work of Public Analysts
3
UNITED KINGDOM
4
DURHAM
5
HISTORY OF FOOD
ADULTERATION

1200 AD – KING HENRY II “GARBLE”

1700 AD – STEADY INCREASE

1800 AD – INDUSTRIAL REVOLUTION
6
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.
AND
METHODS 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 SMALL
1820.
7
Frederick Accum
http://www.gutenberg.org/etext/19031
8
1851 - 54

ARTHUR HILL HASSALL
Purchased and analysed 2500 articles of food
and produced reports in the medical journal
The Lancet identifying many examples of
adulteration of foods.
Information Link:
http://www.rsc.org/Education/EiC/issues/2005M
ar/Thefightagainstfoodadulteration.asp
9
Origin of UK Food Law









1860
1872
1875
1899
1928
1938
1955
1980
1990
1999
ADULTERATION OF FOOD AND DRINKS ACT
ADULTERATION OF FOOD AND DRUGS ACT
SALE OF FOOD AND DRUGS ACT
SALE OF FOOD AND DRUGS ACT
FOOD AND DRUGS ADULTERATION ACT
FOOD AND DRUGS ACT
FOOD AND DRUGS ACT
FOOD ACT
FOOD SAFETY ACT
FOOD STANDARDS AGENCY
10
Modern Public Analysts
English Law
Courts
Environmenta
l Health
Government
Chemist
Food
Standards
Agency
Public
Analyst
Trading
Standards
Central
Science Lab
Consumers
Industry
11
QUOTATION

“The duties of the Public Analyst are daily
increasing in complexity and difficulty.
Higher qualifications than formerly are
required of him, owing not only to the
general advance in science as applied to
the analysis of food, but also the exacting
character of the numerous regulations of
government departments concerned. . . . “

September 1923
12
Mastership in Chemical Analysis
13
Food Safety Act Certificate
14
The MChemA Examination
Theory of analytical instrumentation,
 QA and statistics,
 Methods of testing,
 Laws relating to food, water and animal
feeds
 Practical application of skills
 Ability to write certificates of analysis

15
MChemA Questions

Day 1

Theory of Analytical Chemistry, 3 hours,

Methods of analysis food, drugs & water 3 hours

Day 2
 law related to food, drugs and water, lab administration
 identify the six unknown substances using the microscope

Day 3, 4 and 5
 Practical Demonstration of Skills
http://www.rsc.org/Education/Qualifications/MChemA/Index.asp
16
Certificates of Analysis
Food Safety Act

The FACTS

The STANDARD

The INTERPRETATION
17
Certificates of Analysis

Food Complaint Certificate
 Full History
 Photographs
 Results of Analysis
 Interpretation
 None Technical Report
18
Other Certificates

Agriculture Act Certificates

Statements of Witness

UKAS
19
Official Food Labs
20
Other Work
21
Other Work
22
UK Food Laws
Pre 1980 – mostly set by UK
 EU Influence
 EU Methods of Analysis




Contaminants in Food Regulation 2007
Commission Regulation (EC) No 1881/2006
of 19 December 2006
Commission Directive 2001/22/EC
23
Commission Directive 2001/22/EC


















Specific methods for the determination of lead, cadmium and mercury
contents are not prescribed.
Laboratories shall use a validated method that fulfils the performance
criteria indicated in Table 3.
Where possible, the validation shall include a certified reference material in
the collaborative trial test materials.
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 than 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
(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.
Precision HORRATr or HORRATR values of less than 1,5 in the validation
collaborative trial
Recovery 80-120 %



Specificity - Free from matrix or spectral interferences
24
UK and EU Laws
When searching for UK regulations I need the date of the regulation and
the statutory instrument (SI) number. All current regulations are
available on the internet on the website:
http://www.opsi.gov.uk/
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
website at:
http://www.publicanalyst.com/
25
Sampling

Formal Sampling – passing on

Informal Sampling

Complaints

Regulation sampling

Projects

Surveillance
26
Glass Contamination
27
Fibres
Human Hair
Mouse Hair
28
Faecal Contamination
29
Moulds
30
Infestation
31
Authenticity
Cod
Salmon
Haddock
Coley
32
Modes of Adulteration

‘Stretching’ with neutral spirit
(cereal or non–cereal derived)

Geographic mislabelling

Addition of flavourings

Addition of sweetening

Mislabelling of age
33
Chromatographic Analysis of
Distilled Spirits
Major Volatile Congeners (Mostly alcohols and esters)
Compound
Methanol
Propanol
Isobutanol
2-methyl-1-butanol
Isoamyl alcohol
Ethyl acetate
Isoamyl acetate
Polarity
BP (°C)
Concentration range
polar
polar
polar
polar
polar
65
97
108
130
130
9 – 82
60 – 1330
150 – 620
1 – 360
0 – 770
polar ?
polar ?
77
142
44 – 500
2 - 25
34
20
2
Methanol
25
4
6
8
2-Methyl-1-Butanol
30
iso-Butanol
n-Pentanol
n-Propanol
3-Methyl-1-Butanol
Ethyl Acetate
35
n-Butanol
iso-Amyl Acetate
Acetal
Acetaldehyde
Modes of Adulteration
pA
15
10
12
14
16
18 min
35
76
mAU
35
30
25
Ellagic Acid
77
15
10
5
Vanillic Acid
78
80
79
Signal=260nm
20
0
10
15
10
15
20
25
20
25
Coniferaldehyde
Sinapaldehyde
Syringaldehyde
mAU
Scopoletin
75
Vanillin
Syringic Acid
HMF
Gallic Acid
Cask Extractives
Signal=280nm+340nm
min
min
36
Stable isotope analysis
in food authentication
Detecting the substitution of Organic crops
with conventional produce
Simon Kelly1 & Alison Bateman2
1 Institute of Food Research, Norwich, UK, NR4 7UA (simon.kelly@bbsrc.ac.uk)
2 University of East Anglia, Norwich, UK, NR4 7JT
37
Stable Isotopes of Nitrogen
‘light’ isotope
‘heavy’ isotope
14N
15N
7
7
-
P 7
N 7 - -
99.63 %
- -
P 7
N 8 - -
0.37 %
38
Tomatoes – normal distn
0.20
Conventional
0.18
n=43
Mean = -0.1
n-1 = 2.1
0.16
Probability
0.14
Organic
0.12
n=61
Mean = +8.1
n-1 = 3.2
0.10
0.08
0.06
0.04
0.02
0.00
-10 -8
-6
-4
-2
0
2
4
6 8
d N(‰)air
10 12 14 16 18 20
15
39
Tomato Data - 3-D Scatter Plot for variables d15N‰,
Mn (ppm), Cu (ppm) & Rb (ppm)
40
A METHOD FOR THE
SIMULTANEOUS
DETERMINATION OF
SWEETENERS IN FOODS
Steve Appleton
 Durham Scientific Services


steve.appleton@durham.gov.uk
41
Evaporative Light Scattering
Detector (ELSD)
Gaining popularity as a universal detector.
Simple three step process
 Nebulisation – column effluent forms a
dispersion of droplets
 Evaporation – mobile phase is evaporated,
leaving a fine mist of dried sample.
 Detection – laser light scattered by sample
particles is detected, generating an
electrical signal.
42
Evaporative Light Scattering
Detector (ELSD)
Pro
 since all particles scatter light, all
sample components are detected,
regardless of their structure or optical
properties.
Con
 method limitations as it can only be
used with volatile mobile phases and
mobile phase modifiers
43
ELSD
44
ELSD plus UV
45
Elisa and DNA
Protein
 Heat labile
 Cross reactivity
 Batch variation
 DNA
 Cooked foods
 Specific
 Simplified “lab on a chip”

46
Lab on a Chip
47
DNA Analysis

Applications
 Fish & meat speciation
 Basmati rice authenticity
 Detection of bushmeat
 GMO testing
 Fruit juices
 Durum wheat
48
Fish Speciation
Method uses PCR-RFLP
 A region of a specific gene is amplified
by PCR using universal primers
 Produces a single PCR product of the
same size from all samples
 Can be done on raw, cooked and some
canned fish (not tuna)
 No need for a reference specimen

49
DNA Results
Fish 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
50
Reminder
A WRONG RESULT
IS WORSE
THAN NO RESULT AT ALL !
51
THANK YOU
52