Food safety issues, GMOfood, Food allergens, Hazards, risks, tresholds,

1
Food safety issues, GMO-food, Food allergens,
Hazards, risks, tresholds,
2
Food and Chemical ToxicologyVolume 42, Issue 7,
Pages 1043-1202 (July 2004)

• Safety Assessment, Detection and Traceability,
  and Societal Aspects of Genetically Modified
  Foods
• European Network on Safety Assessment of
  Genetically Modified Food Crops (ENTRANSFOOD)
• Edited by H.A. Kuiper, G.A.Kleter, A. Konig, W.P.
  Hammes, I. Knudsen

3
(No Transcript)
4
Literature data
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
New GM variety An integrated approach to hazard
assessment characterisation of all elements
11
(No Transcript)
12
Demonstration of unintended effects by phenotype
selection or investigation of defined
constituents
13
Assesment by omics- based analyses
Joung J.Nutr 2001, Oliver Nature 2000, Go J.
Nutr 2003
14
Plant protein 2-D databases
15
Example Automated data-analysis
(metabolite-profiling)
16
3H NMR spectra of tomatoes, signals of a
selection of metabolites
17
Antibiotic resistance genes as markers
18
Other marker genes are also in use
RIKILT Report 2000.004.
19
Hazards, risks, tresholds
20
Example

• Allergic response as a potential hazard

21
Genome Res. Institute
22
What is an allergy anyway?

• Hypersensitivity diseases
• Disorders,
• caused by excessive / aberrant immune responses,
• causing tissue inflammation and organ dysfunction
• In some texts Hypersensitivity and sensitivity
  are synonyms for allergy!

23
Summary of hypersensitivity reactions
24
(No Transcript)
25

• Adapted from Saarinen, Lancet 1995

26
Allergic urticaria, angioedema
27
Allergens, classification, according to the

• Route of exposure
• Inhalants
• Ingestants
• Contactants
• Injectants

28
Inhalant allergens

• Pollens
• Fungi (Molds)
• Animal products
• Mammalian
• Anthropod
• Dusts
• Algae

29
Major sources of pollens

• Trees (e.g. Birch, Ash, Maple, Cedar, Pine,
  hazel, Alder,Cypress etc)
• Grasses (Timothy grass)
• Weeds (e.g. Ragweed, Mugwort

30
Sources of Allergenic fungal (mold) spores

• Field(seasonal)
• Alternaria
• Cladosporium
• Helinthosporium
• Storage (perennial)
• Aspergillus
• Penicillium
• Epicoccum

31
Animal inhalant allergens

• Epidermal
• Dander (desquamated epithelium)
• Cuticule (Body)
• Excretions
• Saliva,
• Urine,
• Feces

32
Basic allergens in foods

• Proteins
• - most important allergens
• Carbonhydrates
• Mostly polysaccharides
• dextran anaphylaxis (cross reactive with some
  Pneumococcus polysaccharides) 
• glycoproteins
• lipopolysaccharides
• Fats, lipids
• Phospholipids (lecithin, cephalin)
• Sterols ( cholesterol, ergosterol, phytosterols
  etc)

33
(No Transcript)
34
Common allergens among foods

• EU Cows milk, hens egg, fish, maize, nuts,
  chocholets, soybeen, wheat
• US wheat, cows milk, eggs, maize, cheese,
  tomato, fish, seafood
• Adults
• Fruits, vegetables are more common allergens
• Mango, bananas, figs,avocado (all of them cross
  allergies with Latex!) furthermore tomato,
  citruses etc)  

35
Cows milk protein allergy- manifestations

• Cows milk protein allergies
• approx. 2,5 of children effected
• (1 IgE mediated, 1,5 non IgE mediated)
• History
• Start 1st year of life
• Most cases resolve by school age
• Most common symptoms
• Skin signs, Gastrointestinal symptoms 50-70
• Bronchopulmonary manifestations (asthma etc)
  20-30
• In rare cases arthritis-like symptoms

36
Potential allergens among cows milk proteins
(CMP)

• In Coagulum (curd) (80 of CMP)
• Caseins, Heat-stable in 60 of milk protein
  allergiesmpa),
• In Whey (lactoserum) proteins (20 of CMP)
• Beta lactoglobulin (BLG), Heat-stable in 60-80
  of mpa-s
• Alpha lactalbumins(ALA) in 50 of mpa-s),
• (Bovine) Serum albumin in 50 of mpa-s,
• Peptons,
• Maillards products (Amino-lactose reaction
  products)

37
Potential allergens in hens eggs

• In albumen (egg white)
• Ovalbumin,
• Ovomucoid (heat stable)
• Conalbumin (Ovotransferrin)
• Lysosyme
• Sglobulins, other trypsin-inhibitors
• In yolk (vitellus)
• alpha-livetin chicken serum albumin
• (cross reactive in bird-egg syndrome
• yolk, chicken-meat, poultry feather,
  par(r)akeet-Zwergpapagei)

38
Peanut allergy

• Prevalence 0.6-1.5 (increasing)
• 80 of children allergic symtoms at the first
  known exposure to peanut!
• In spite of avoidance, many accidental exposures!
  (Most common cause of fatal, food-related
  anaphylaxis!)
• 20 of patients will become tolerant later

39
Some other examples of food allergens

• cereals like maize, wheat
• Prolamin superfamily, incl.gliadins, glutenins)
  
• Storage proteins
• LTPs (lipid transfer proteins,
• 2S albumins ,
• Alpha amylase inhibitors
• Seed
• Cupin superfamily
• e.g. storage globulins
• Fish parvalbumin

40
sensitisation via the lungs

• May occur in adults mostly by inhalation, as
  occupational exposure
• Examples
• Bird/egg syndrome
• Plant food proteins
• E.g. 2S albumins and alpha amylase and trypsin
  inhibitors of cereals

41
Cross-reactivity
42
Cross- allergies examples-I.

• Common allergen Bet v-1allergen family
• First described as birch pollen allergen
• Present in other tree pollens, carrot, cherry,
  and hazelnut
• some other homologues
• apple Mal d1,
• Celery Api g1

43
Cross- allergies examples-II.

• Shrimp major allergen
• (Pen a 1) is muscle protein Tropomyosin
• Tropomyosin is important allergen in
• Other crustaceans like lobsters, crab, oyster
• Butvertebrate tropomyosin is not allergenic
  high structural homology with human tropomyosin

44
Major allergens of Birch (bet v1) and of apple
(Mal d1) are related Cross-allergies!
45
Oral allergy syndrome (Recent name Plant-food
allergy syndrome)

• In hay fever patients (seasonal allergic
  rhinitis)
• Sensitised against
• Pollen allergens, e.g. grass or birch pollen
  allergens
• Oropharyngeal ithcing, sometimes laryngreal
  oedema
• Caused by cross-allergens! (E.g. from apple, mal
  d1!)

46
EC-funded project (SAFE)

• Aim to reduce incidence of food allergies by
• Identifying apple allergens as test model
• Mal d1-4 were identifed, cloned and sequenced
• RT-PCR and ELISA tests were developed to detect
  allergen specific m-rna and protein in apple
  cultivars
• Allergen genes were mapped on a molecular linkage
  map of apple

47
(No Transcript)
48
(No Transcript)
49
(No Transcript)
50
(No Transcript)
51
Hazards, risks, tresholds of allergens

• Hazard
• intrinsic capacity of a food component to induce
  an allergic response
• Primer /secunder risks
• Statistical likelihoods of allergic response to a
  food component at non-sensitise/sensitised people
• Treshold
• The (lowest) estimated eliciting dose (EED)

52
Range of estimated eliciting doses

• EED Broad ranges ! Examples
• For peanut
• EED from 100 µg to 1 gram
• For hazelnut
• EED From lt100 µg to 100 mg

53
Factors influencing EED

• Patient- related factors
• Age, body weight, asthma status, allergy (pollen)
  season for patients with OAS,
• oral allergy syndrome
• Medication, excercise, alcohol intake
• Product related factors
• ingredient source (cultivar), purity,
  processing (heating etc) fat content, form (e.g.
  milk liquid whole, non fat dry or infant formula
  etc)

54
New EU directive on labelling foods

• In principle
• All ingrediens have to be listed with some rare
  exceptions
• only with scientifically established proof for
  not causing adverse reactions)
• BUT major allerginic foods have to be listed

55
Major allergenic foods listed in Annex III of the
EU labelling directive

• Cereals containing gluten (wheat, rye, barley,
  oats, spelt or hybridized strains)
• Crustaceans, Eggs, fish,peanuts, soybeans, milk,
  nuts, mustard, sesame seeds and their products
  thereof
• Sulphur dioxide and sulphites at conc. of more
  than 10 mg/kg or 10 mg/liter expressed as SO2

56
Allergen databases, internet
BMC Structural Biology2002, 2, 8.
http//www.biomedcentral.com/1472-6807/2/8.