Lecture 3 - food additives Flashcards
Food additives are
substances added intentionally to foodstuffs to perform certain technological functions, for example to color, to sweeten or to help preserve foods.
In the European Union all food additives are identified by an
E number.
Food additives are always included in the ingredient lists of foods in which they are used.
Product labels must identify the function of the food additive in the food (e.g. food coloring,
food preservative) and the specific substance used either by referring to the appropriate E number
or its name (e.g. E 415 or Xantham gum).
The most common additives to appear on food labels are
antioxidants (to prevent deterioration caused by oxidation), color additives, emulsifiers, stabilizers, gelling agents and thickeners, preservatives and sweeteners.
Food supplements are
concentrated sources of nutrients or other substances with a nutritional or physiological effect, whose purpose is to supplement the normal diet.
e.g. vitamins, minerals, fibers, amino acids, fatty acids, lactic acid bacteria.
Supplements may be used to
correct nutritional deficiencies in foods, or maintain an adequate intake of certain nutrients.
ADI
Acceptable Daily Intake – is a measure of the amount of a specific substance in food or drinking water that can be ingested (orally) on a daily basis over a lifetime without an appreciable (noticeable) health risk.
ADIs are usually expressed in milligrams (of the substance) per kilogram of body weight per day
– for calculation of ADI, a standard body mass of 60 kg is used.
TDI
tolerable daily intake (TDI) is the analogous term (to ADI) used for (food)contaminants.
GDA
Guideline Daily Amounts – the amount of energy and nutrients for the average adult.
GDAs are guidelines for healthy adults and children about the approximate amount of calories, fat, saturated fat, total sugars, and sodium/salt.
5 most important ones:
energy – 2000 kcal;
sugars – 90 g;
fats 70 g;
saturated fatty acids – 20 g;
salt – 6 g (average adult per day).
RDA
Recommended dietary allowance – are your daily guideline intake for all macro nutrients (protein, carbohydrates and fats) and micro nutrients (vitamins and minerals).
GRAS
Generally Recognized As Safe - is an American Food and Drug Administration (FDA) designation
that a chemical or substance added to food is considered safe by experts, and so is exempt from the usual Federal Food, Drug, and Cosmetic Act (FFDCA) food additive tolerance requirements.
According to origin, food additives can be divided into three groups:
- Substances which are separated/extracted from the food
- Nature-identical substances which are present in nature but obtained by synthesis
- Substances which are obtained by synthesis and which do not have analogues in nature
The most harmful food additives are
synthetic food additives which do not have
analogues in nature.
These are foreign substances to our body and their final metabolic pathways in human body are missing or not known yet.
During decomposition (digestion) of certain food additives intermediate substances can emerge
which could be mutagenic, teratogenic or carcinogenic.
E100 – E199 are all what?
colorants/dyes (color additives)
If the food product is brightly colored then there is a high probability that it contains
azocolorants
azocolorant = synthetic food colorant
Harmful health effects should be tested taking into account
toxic, synergic and cumulative effect.
To ensure that the use of food additives will not cause exceeding of the ADI values, what is established?
consumption limits and the maximum permitted levels in foods are established for potentially hazardous E-substances.
For many food additives the ADI-value is not established because
their use in normal quantities is safe, therefore they are generally recognized as safe (GRAS) substances.
GRAS = generally recognized as safe
Safety factor 100 is usually used while establishing the quantity of food additive allowed in food for human consumption. This means what exactly?
That the ADI is usually derived by the application of a 100-fold safety factor to
the “no observable adverse effect” level (NOAEL) in (animal?) experiments.
How many E-substances are used in food production today?
more than 3500 E-substances used for food production.
Nitrate (NO3-), Nitrite (NO2-) - their degradation product is
nitrogen oxide (NO).
Sodium nitrite (E250), Sodium nitrate (E251) or Potassium nitrate (E252) are added into
meat products for the purpose of?
as preservative and color fixation substances.
These substances are also giving some taste properties and are acting against microbes
(bactericidal effect).
Sodium nitrites give red color to meat and act against Clostridium botulinum.
Nitrites have a Bactericidal effect mostly against
Clostridium botulinum.
Sulphites have an ability, via transformation, to produce multifunctional reagent sulphur dioxide SO2 (E220), which controls
microbial growth.
Sulfites are commonly introduced to arrest fermentation at a desired time, and may also be added to wine as preservatives to
prevent spoilage and oxidation at several stages of the winemaking. Also, sulfites occur
naturally in all wines to some extent.
