Summary FCH-21808 Biochemical aspects

Biochemical aspects
Classification and definitions
• Introduction
- Large number of different components of food may cause adverse reactions
o Response of a person can differ widely depending on the type of response and the
component causing it
- Important to distinguish between different causes of adverse reactions
- Non-responses
o Blue bars overall smaller than orange bars  more allergy mistakes than product
recalls  not directly a recall when allergy  relabelling or message
o Toxic = directly recall




- Bruynzeel-Koomen scheme




• General classification
- Adverse reactions
o Aversion
▪ Person ingests the food and immediately develops a response lading to further
refusal of the food
▪ Caused by a dislike of the food
▪ Result of a decision not to eat  commonly with young children
▪ Psychosomatic  should be taken seriously
➢ Forcing to continue eating will lead to incomplete digestion  no
healthy situation


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, ▪ Symptoms upon ingestion like nausea, sickness and gastrointestinal
discomfort are psychosomatic
▪ Extreme manifestations: anorexia nervosa and bulimia nervosa
▪ Sometimes difficult to distinguish from toxic or intolerance responses 
symptoms are similar
o Non-toxic response
▪ Allergy
➢ IgE mediated reactions are severe and immediate (Peanut allergy)
➢ Non IgE mediated (often not called allergy) reactions are delayed and
complex (Coeliac disease, reactions to cow milk)
▪ Intolerance
➢ Enzymatic
➢ Pharmacological
o Toxic response  nightmare for food producer = immediately recall  food
poisoning
▪ Important question: are you the only one who is reacting to this food?  toxic
infection affects all people who eat
➢ Poisoning is food specific (rather than person specific)
▪ Ingestion of food causes a disease of a toxic or infectious nature
➢ Chemicals: residues of herbicides, fungicides, antimicrobial agents,
heavy metals, fertilizers
➢ Natural toxins: resulting from incomplete processing, spoiled raw
materials
➢ Bacterial infections: campylobacter contamination, salmonella
▪ Insecticides
➢ Used in production of fruit and vegetables  food industry has
responsibility to monitor both the amount and identity of the
insecticide used  prevent foods and vegetables that do not comply
and exceed threshold levels reach the consumers
➢ Exposure to residues is low: some insecticides are not toxic to humans
and do decompose rapidly in environment
▪ Heavy metals
➢ Lead, tin, copper and zinc  due to improper packaging material or
storage containers
➢ Responsibility for food producer to prevent this by carefully monitoring
process equipment and quality of storage materials (especially when
storing acidic foods or beverages)
➢ Sometimes via primary process: cows eating grass contaminated with
mercury  spoiled by near by factory
➢ Requires systematic and frequent monitoring
▪ Natural toxins, endogenous
➢ Incomplete processing  natural toxins present in food can survive
and end up in finished products
➢ Relevant with plant foods  may contain substantial amounts of
natural toxins (beans)
➢ Glycosides can release cyanide (potent toxin) upon storage/processing
or on contact with stomach acid  lima beans contain this (especially
the wild varieties)
▪ Natural toxins, exogenous
➢ As result of contamination by bacteria, moulds (mycotoxins), algae and
insects  produce chemicals
➢ Toxins originates from algae that accumulate in seafood




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,• Non-toxic reactions  related to individual rather than the food




- Allergy
o IgE mediated and non-IgE mediated  both are different in terms of severity and
immediacy of the reaction
▪ IgE: more immediate and more severe (on shot term) than non-IgE
▪ Is in both cases the recognition by immune system that starts adverse
response
o Reaction can be immediate and severe  indicative of IgE mediated reaction
o Reaction can also remain hidden for many years  difficult to diagnose (celiac
disease)  non IgE
▪ Offending gluten protein directly binds to T cellstriggering immune response
o Major allergens




o Main/major allergens
▪ Typically affects a lot of people (thousands)  large groups of population
have to avoid
▪ Legislation regulated  have to be labelled
o Minor allergens
▪ Typically affects less people (hundred)
o People can become allergic for everything
▪ Exposure to components (probably) will cause an allergic reaction
o Incidence
▪ Product should at least contain what is on the label
▪ 30% op people think they have to avoid some type of food
➢ Often not related to allergy
▪ Significant number of people is choosing its daily diet with aim to avoid
adverse reactions  challenge for food industry: provide maximal
opportunities for selection

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, - Intolerance
o Enzymic reactions
▪ Related to absence or lack of metabolic enzymes
➢ Lactase deficiency (lactose  glucose + galactose)  lactose not
converted and remains present in intestine  metabolized by MO 
organic acids and gasses  diarrhoea, pain and bloating
❖ Deficiency starts to develop from age of 5
❖ Primary: absent as congenital characteristic
❖ Secondary: related to damage of lactase producing cells
because of inflammation
➢ G6-PDH deficiency (Favism) enzyme helps to protect against
oxidation  people that eat fava beans (contains extremely toxic
molecules for blood cells)  enzyme not available  blood cells break
up  haemolytic anemia
▪ Acquired: gut related disease/medication which is affecting that
(chemotherapy)  result in lack of enzymes
o Pharmacological
▪ Caffeine
▪ Histamine, tyramine
▪ Capsaicin
▪ Ethanol/alcohol
▪ Compounds causing pharmacological reactions




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