Upload
anahusni
View
130
Download
1
Tags:
Embed Size (px)
Citation preview
(your name)
(your class)
(college number)
Chemical Consumers 2011
2
Food Additives
A chemical substance that are added to food in small quantities for specific purposes such as:
Making food last longer by: Preventing the growth of microorganism Preventing the oxidation of fats and oils by oxygen in air
Making food taste or smell better
Improving the texture of food and to prevent food from becoming liquid
Restoring the colour of food destroyed during food processing
Adding colouring to food so as to make the food look fresher, more interesting or more appetizing.
Chemical Consumers 2011
3
Type of food additives
Preservatives
Antioxidants
Thickeners
Dyes
Flavouring agents
Stabilisers
Chemical Consumers 2011
Preservative Molecular formula
Uses
Sodium nitriteSodium nitrate
NaNO₂NaNO₃
To preserve meat, sausage, cheese and dried fish. To prevent food poisoning in canned foods. To maintain the natural colour of meat and to
make them look fresh.Benzoic acidSodium benzoate
C₆H ₅COOH
C₆H ₅COONa
To preserve sauces (oyster, tomato or chilli), fruit juice, jam and margarine.
Sulphur dioxideSodium sulphite
SO₂
Na₂ SO₃
Used as bleaches and antioxidants to prevent browning in fruit juices.
Maintain the colour and freshness of vegetables. To prevent the growth of microorganism.
4
Preservati vesChem icals that are added to food to retard or to prevent the grow th of m icroorganism s (bacteria, m ould , fungus, etc.) so that the food can be stored for a longer period.A ncient preservati ves used - salt, sugar & vinegar.M odern preservati ves used - syntheti c preservatives (as show n in tab le be low ).
Chemical Consumers 2011
5
AntioxidantsChemicals that are added to food to prevent the oxidation of fats and oils by oxygen in the air.Food containing fats or oils are oxidised and become rancid when exposed to air, thus making the food unfit for consumption. The rancid products are volatile organic compounds with foul odours (eg : butanoic acid, C₃H₇COOH).Antioxidants are added to fats, oils, cakes, sausages, biscuits and fried food to slow down the oxidation process.Eg: Ascorbic acid, citric acid and sodium citrate.
DyesColoring agents are chemicals that are added to food to
give them color so as to improve their appearance.Some foods are naturally colored, but the color is lost
during food processing. The food industry uses synthetic food colors to :
-restore the color of food lost during food processing-enhance natural colors, so as to increase the
attractiveness of food-give color to food that does not have color.
Some dyes are natural plant pigments while others are synthetically prepared (azo & triphenyl compounds).Brilliant blue is an example of triphenyl compound.
Tartrazine and sunset yellow are examples of azo compounds.
Azo compound are organic compounds containing the diazo group, - N = N -, and are usually yellow, red, brown or black in three phenyl groups , -C₆H₅, and are usually
green, blue or purple in colour.
Chemical Consumers 2011
Ester Benzyl ethanoate
Octyl ethanoate
Ethyl Butanoate
Flavour Strawberry Orange Pineapple
6
Flavouring agents:- Artificial flavors
- Flavor enhancers
Flavor enhancers:- Have little or no taste of their own.-Added to bring out the flavors or to enhance the tastes of food.-E.g.: monosodium glutamate (MSG)
Artificial flavors
- include sweeteners and other flavors such as peppermint or vanilla.- E.g.: aspartame & saccharin (both artificial sweeteners)- However saccharin is banned in many countries as it is a suspected carcinogen.- Many esters have fruity odours and tastes (as shown in diagram below)
Chemical Consumers 2011
7
Stabilisers and Thickening Agents- Both improve the texture and the blending of food.
- Stabilisers : chemicals that are used to enable oil and water in the food to mix together properly in order to form an emulsion. - For example, stabilisers are added to ice cream and peanut butter to keep them smooth and creamy.- Without stabilisers, ice crystal would form in ice cream, particles of chocolate will settle out of chocolate milk, oil and vinegar in salad dressing will separate as soon as mixing is stopped.- E.g.: gelatin, acacia gum, lecithin, & pectin
- Thickening agent : chemicals that are added to food to thicken the liquid and to prevent the food from liquefying. Thickening agents (also called thickeners) absorb water and thicken the liquid in food to produce a jelly-like structure.- Most thickening agent are natural carbohydrates. Gelatin & pectin are added to help jam and jellies set.
Chemical Consumers 2011
E Numbers to Avoid
1. E102 – tartrazine. This yellow food colouring has already been banned from use in Norway and Austria, yet it’s continued being used in food and drinks in the UK. In recent years, since a study
found it was linked to hyperactivity in children, the UK government have suggested it
should be avoided by children, but adults may well want to avoid it too. E102 is commonly found in products such as mustard, marmalade, jelly, marzipan, ice lollies, fizzy drinks, squash, custard powder and soups.
2. E122 – carmoisine. E122 is a synthetic red dye that’s used as a colouring in many foods. Already banned in several countries, including Norway, Japan, America and Sweden, this colouring is found in products such as sweets, yogurts, packet soup, jelly and jam. It has been positively
linked to hyperactivity in children and the UK government recommend that children
may be better avoiding it, but it can also cause allergic reactions in adults too.
3. E129 – allura red. E129 is a red or orange like synthetic dye which is used as a food colouring in
drinks and sweets. As well as being linked to hyperactive behaviour in
children, it may also cause allergic skin reactions in adults, especially anyone
8
To Prevent Food Spoilage For Medical Reasons
Chemical Consumers 2011
sensitive to aspirin. It’s worth noting that E129 has already been banned in many countries, including France, Germany, Belgium, Austria, Norway and Sweden.
4. E104 – quinoline yellow. As the name suggests, E104 is a synthetic yellow colouring and is used in products such as smoked haddock and scotch eggs to provide a yellow tinge. Already banned in countries such as Japan, America, Australia and Norway, the colouring has been linked to
health and hyperactive problems in children.
5. E621 – monosodium glutamate. Otherwise known as MSG, E621 is a flavour enhancer that’s commonly used to pep up food products and make them taste better. Unfortunately, it is known to cause problems for some people – and certain people seem to more sensitive to its effects than others. Amongst the known side effects, MSG can cause symptoms such as
headaches, nausea, dizziness, muscle pain, palpitations and even pain.
6. E951 – aspartame. E951 is an artificial sweetener that’s commonly used as a sweetening ingredient. In particular, it’s often found in products aimed at dieters or diabetics, such as desserts, low-fat foods, low sugar drinks, snacks and sweets. It’s well known to be linked to problems in people, who suffer from the condition PKU, and they are people too and side
effects, such as headaches, have often been reported.
7. E211 – sodium benzoate. E211 is an E number that’s used as a preservative and is found in products such as margarine, salad dressing, soy sauce, sweets and soft drinks. Studies have
found that it’s linked to hyperactivity in children, plus it may cause reactions in people have allergic conditions or asthma.
8. E151 – black PN / brilliant black BN. E151 is a form of black synthetic dye that is used as a food colouring in some products. However, concerns have been raised in other countries, as it’s been
linked to allergic reactions in some people. It is already banned in Australia,
Austria, America, Germany, Norway, Sweden, Switzerland, Belgium and France.9. E133 – Brilliant blue FCF. E133 is another synthetic colouring dye, which adds a blue colour to
some products. Some people have been found to experience allergic reactions
after consuming products containing E133 and this E number is already banned in Austria, Sweden, Switzerland, France, Germany and Norway.
10. E213 – calcium benzoate. E213 is a form of preservative that’s used to lengthen the shelf life of foods and drinks. It’s often found in low sugar products, but it has been linked to side effects in people who have allergic conditions
9
Chemical Consumers 2011
10
Chemicals that cause cancer are called carcinogens. Sodium Nitrite (a preservative) is a potent carcinogen.
The nitrite reacts with the amines in food to produce nitrosamine which can cause cancer.
Carcinogenic nitrosamines are formed when amines that occur naturally in food
react with sodium nitrite found in cured meat products.
R2NH (amines) + NaNO2 (sodium nitrite) → R2N-N=O (nitrosamine)
Chemical Consumers 2011
Sources and uses of
Traditional Medicines
1. A medicine is a substance used to prevent or cure diseases or
to reduce pain and suffering due to illnesses. 2. Traditional medicines are medicines derived from natural
sources such as plants and animals without being processedchemically.3. Medicines obtained from plants are known as herbalmedicines. The sources and uses of some herbal medicines areshown in table below;
Plant Part of the plant used UsesGarlic Corm For preventing flu or asthma attacks
For reducing high blood pressureGinger Rhizome For treating stomach pain due to wind in the stomach
For supplying heat energy to keep the body warmFor preventing flu attack
Aloe Vera
Leaves For treating itchy skinFor treating burns (scalding) on the skin
Lemon (lime)
Fruits For treating boils or abscesses on the skinFor preventing flu attackFor treating skin disease
Quinine Bark of Cinchona tree For treating malariaFor preventing muscle cramps
Ginseng Roots As a tonic to improve overall health of human beingsFor increasing energy, endurance and reducing fatigue
Lemon grass
Stem/leaves Has antibacterial and antifungal propertiesFor treating coughs
Tongkat Ali
Roots As a tonic for after birth and general health
11
Chemical Consumers 2011
Modern Medicine
Can be classified as follows
based on their effect on the human body:
12
Analgesics
- medicine that relieves pain- eg: aspirin, paracetamol (both
mild painkiller)and codeine (powerful painkiller)
eg; aspirin
eg; paracetamol
eg; codeine
Relief pain and has anti-inflammatory action
Used to; Reduce fever Relieve headaches, muscle aches, and
joint aches Treat arthritis Act as an anticoagulant (prevent the
clotting of blood & reduce the risk of heart attacks and strokes)
Structural formula:
*acidic in nature
Used to relieve minor to moderate pain. It is more powerful than aspirin and paracetamol but less powerful than morphine. Codeine m& morphine are narcotic drugs
Also used in cough mixtures for suppressing coughs
Chemical aspect: Codeine is organic compound that
contains the element carbon, hydrogen, oxygen & nitrogen.
Similar to aspirin in its effect but it does not reduce inflammation
Reduce or relieve flu symptoms such as fever, bone aches, and runny nose
Structural formula:
*neutral in nature
Chemical Consumers 2011
13
Antibiotics: Antibacterial medicine
- Chemocals that destroy or prevent the growth of
infectious microorganism
used to treat disease caused by bacteria and not effective against disease caused by viral infections
such as influenza, measles or small pox
eg; penicillin
eg; streptomycin
Derive from the mould Penicillium chrysogenum
Used to treat disease, caused by bacteria, such as pneumonia, gonorrhoea and syphilis
Only effective on certain bacteria. For example, it cannot be used to treat tuberculosis.
Streptomycin is the antibiotic that is effective in treating tuberculosis
Chemical Consumers 2011
Of modern medicine
14
Chemical Consumers 2011
*penicillin cause allergic reactions
*Antisypchotic drug effects
15