1. Food Additives
Gan Jia Jie, 2A4

2. What are Food Additives? (I)
Food additives are chemical substances added to foods to improve flavour, texture, colour, appearance and consistency.

3. What are Food Additives (II)
Food additives may be natural or artificial.
Common natural additives include sugar, salt, corn syrup, baking soda, and pepper.
Many modern additives, such as vitamins and some flavours, are made in a laboratory but most of them are exact replicas of naturally occurring substances and the body is unable to distinguish between the natural and artificial forms.
Direct additives are those that are intentionally added to foods for a specific purpose.
Indirect additives are those to which the food is exposed during processing, packaging, or storing. Preservatives are additives that inhibit the growth of bacteria, yeasts, and molds in foods.

4. Purpose of Food Additives
Food additives are substances intentionally added to food either directly or indirectly with one or more of the following purposes: 1. To maintain or improve nutritional quality 2. To maintain product quality and freshness 3. To aid in the processing or preparation of food 4. To make food more appealing 5. Control the acidity and alkalinity, and to provide leavening.

5. Common Types of Food Additives
Colors
Emulsifiers
Flavorings
Gelling agents
Preservatives
Sweeteners
Anti-cake agents
Antioxidants
Acidulants

6. Colors Color is commonly added to foods, for good visual appeal.
Food colors are divided into 3 main types:
Natural Colors
Nature Identical Colors
Synthetic Colors

7. Natural Colors
These are obtained from natural sources such as grasses, leafy vegetables, fruit skins, roots and seeds of plants.
Animals can also be a source of food colourings. Cochineal, or carminic acid, is a red colour that is obtained from the bodies of certain scale insects.
Beet
Carmine
Grape

8. Nature Identical Colors
The colors are exactly the same molecules found in natural sources but they are made synthetically.
Alchoholic Beverages
Diary and Ice Cream
Bakery Products

9. Synthetic Colors
These are colors that do not occur in nature and have been made in a factory. They have been carefully tested to make sure that they are safe

10. Emulsifiers
There are two types of emulsions. An oil-in-water emulsion contains small droplets of oil that are dispersed in water. Alternatively, a water-in- oil emulsion has small droplets of water that are dispersed in an oil.
They are used to aid in the processing of foods and also to help maintain quality and freshness. In low fat spreads, emulsifiers can help to prevent the growth of moulds which would happen if the oil and fat separated.
The emulsifier keeps oil and water mixed. With out an emulsifier water and oil would be separate.
Soy Based Emulsifier

11. Flavorings
The brain interprets signals from taste, smell and even vision before turning them into an impression of the food's taste. Different people will find different tastes nice or unpleasant.
Flavorings are added to food products to give, enhance or intensify flavor.
Foods may contain more than a thousand chemical compounds that contribute to their flavor.

12. Gelling Agents Gives shape and structure.
Thickeners or thickening agents make foods thicker.
Stabilizers help to maintain the physical and textural properties of foodstuffs through their production, transport, storage and cooking.

13. Gelling Agents
The substances belonging to this group are high molecular weight compounds. They are usually proteins, such as gelatin, or complex carbohydrates like pectins , starches, alginates and gums.
Most are long chain molecules (polymers) that are made up of hundreds of linked units called monomers.
They can be divided into a number of categories depending on their source of origin.

14. Preservatives
Food preservation is the procedure of treating and handling food to prevent or greatly slow spoilage (lack of quality, edibility or nutritive value) caused or accelerated by micro-organisms.
Most preservatives today are actually fungistatic in their action. That means they prevent the growth of fungi, molds and yeast.
They have little effect on bacteria but using a combination of preservatives, with antibacterial properties, can give food all round protection.
Food preservatives help to control the spread of bacteria which can cause life threatening illnesses such as salmonellosis or botulism.
There are mainly 3 types of preservatives:
Natural Preservatives
Artificial Preservatives
Chemical Preservatives

15. Natural Preservatives
Natural preservatives are considered safer by many because they have always existed in nature and our immune systems are used to them. Most of the preservatives that come from a plant source are safe for humans.
Popular Natural Preservatives
Neem Oil
Salt
Sugar
Lemon
Honey
Citric Acid
Bee Propolis
Rosemary Extract
Grapefruit See Extract
Potassium Sorbate
Alpha tocopherol (also known as vitamin E)

16. Artificial Preservatives
Artificial preservatives are a group of chemical substances added to food, sprayed on the outside of food, or added to certain medications to retard spoilage, discoloration, or contamination by bacteria and other disease organisms.
Artificial food preservatives can be divided into three major groups, antimicrobial agents, antioxidants and chelating agents.

17. Chemical Preservatives
Chemical preservatives are added to food to keep them fresh and unspoiled during storage.
There are three classes of chemical preservatives commonly used in foods:
Benzoates (such as sodium benzoate)
Nitrites (such as sodium nitrite)
Sulphites (such as sulphur dioxide)

18. Methods of Food Preservation
How it Works
Canning
Foods are sealed into cans and then heated to a high temperature (above 100°C). This kills any microbes in the food and the sealed can prevents fresh contamination.
Freezing / chilling
Lowering the temperature slows enzyme activity in the food spoiling microbes. This slows cellular respiration and therefore growth. The colder the temperature, the slower the growth. However, microbes are not killed when they are chilled. Foods heated up may still contain microbes that are alive and need to be thoroughly cooked before being eaten.
Drying
Removes water from the food and so dehydrates the microbes. This prevents their growth but does not remove any toxins that may already be present.
Pickling
Vinegar is acidic and lowering the pH of the food can prevent the growth of microbes. The acidic environment reduces the enzyme-activity of the food-spoiling microbes.
Jam-making
Jams contain high concentrations of sugar. This effectively draws water out of any microbes in the food and dehydrates them. This method of preservation is traditionally used to make jams.
Smoking
Possibly the oldest known method of food preservation. Foods are hung in wood smoke and chemicals in the smoke act to kill microbes in the food and also give it a distinctive flavour. This ancient method survives into our modern times. Some meat, particularly bacon, and fish, such as haddock and salmon, are smoked.
Preservatives
Some methods of preserving food depend on the use of additives. These substances reduce the growth of microbes but must not be seen as an alternative to proper food hygiene and cooking. Preservatives play their part in clean and hygienic methods of food production.

19. Sweeteners
Provide texture in baked goods it stops them from drying out.
Lowers the freezing point in ice creams
Acts as a preservative in jams
Strengthens "mouthfeel" in soft drinks
Adds bulk to baked goods

20. Anti-caking Agents
Processed foods often contain ingredients that are mixed as powders.
Anti-caking agents are added to allow them to flow and mix evenly during the food production process.
They rarely have nutritional value and only a small proportion of the additives find their way into the food.

21. Antioxidants
Antioxidants are added to food to slow the rate of oxidation and, if used properly, they can extend the shelf life of the food in which they have been used.
Spoilage of fat is called rancidity. All fat containing foodstuffs like nuts, breakfast cereals or potato chips have a tendency to become rancid. Antioxidants are added to these products to prevent rancidity.
There may be health benefits from the use of antioxidants.
Oxidation reactions in the body could be linked to the build-up of fatty deposits that cause blockages in arteries that can cause heart attacks. Antioxidants may be important in preventing this and there could also be a link with the prevention of certain cancers, arthritis and other conditions.

22. Range of Antioxidants Antioxidant Typical foods
Ascorbic acid (vitamin C)
Beers, cut fruits, jams, dried potato. Helps to prevent cut and pulped foods from going brown by preventing oxidation reactions that cause the discolouration. Can be added to foods, such as potato, to replace vitamin C lost in processing.
Tocopherols
Oils, meat pies. Obtained from soya beans and maize. Reduces oxidation of fatty acids and some vitamins.
Butylated hydroxyanisole (BHA)
Oils, margarine, cheese, crisps. Helps to prevent the reactions that break down fats and cause the food to go rancid .
Citric acid
Jam, tinned fruit, biscuits, alcoholic drinks, cheese, dried soup. Naturally-occuring in citrus fruits like lemons. Helps to increase the anti-oxidant effects of other substances. Helps to reduce the reactions that can discolour fruits. May also be used to regulate pH in jams and jellies.

23. Acidulates
Acidulants are additives that give a sharp taste to foods. They also assist in the setting of gels and to act as preservatives.
Common acidulates; acetic acid, citric acid, fumaric acid, lactic acid, malic acid, phosphoric acid, tartaric acid.

24. Twelve Most Dangerous Food Additives
1. Sodium Nitrate, Sodium Nitrite 2. BHA and BHT 3. Propyl Gallate 4. Monosodium Glutamate 5. Hydrogenated Vegetable Oil 6. Aspartame 7. Acesulfame-k 8. Food colorings: blue 1,2; Red 3;Green 3;yellow 6 9. Olestra 10. Potassium Bromate 11. White Sugar 12. Sodium Chloride

25. Are Preservatives Safe?
Food preservatives have to be safe for human consumption.
They can stop the food-decay microbes from growing but must not harm the cells of the human body.
There are also maximum levels of preservatives allowed, so that high concentrations of preservatives in food are not permitted.

26. Health Risks of Preservatives (i)
Usage of preservatives have to be regulated as excessive consumption pose health risks.
Sulfur dioxide and sulphites are used in fruits, wines and dried fruits and vegetable, in order for these products to avoid turning to brown. But sulphites are linked with hyperactivity and it is not recommended for people who are suffering from asthma.
Many food products use Butylated hydroxyanisole (BHA) and hydroxytoluene (BHT) as preservatives. But with these preservatives, it can cause tumors and cancer for their carcinogenic characteristics. Cholesterol imbalance, hyperactivity, asthma attack, and some other disorders are linked to products that use BHT as preservative. These are considered the two most dangerous preservatives. BHT is banned to several countries across the globe.

27. Health Risks of Preservatives (II)
Benzoic acid which is added to sauces in food is linked to hyperactivity and also skin and eye irritations. Asthmatic people can not consume products with benzoic acid. It also can cause neurological problems.
Sodium Citrate is used in meat and baby food but also in personal care products. Large amounts can cause bladder tumors. However, Sodium Citrate is related to Citric Acid and is much safer than other synthesized food preservatives.
Tertiary butylhydroquinone (TBHQ) are added to fats, oils and margarine, so they are often found in snacks like chips. It can cause nausea and delirium. It is petroleum based. Not much information is available about this preservative and it has been referred to as the "mystery preservative“ and one which should be wary of.
Nitrates are used to bring up the flavor to a higher notch. Large use of nitrates is already fatal to one’s health. Nitrate is bad for the blood because it will be converted in the blood to form a harder substance that makes it really difficult for the blood to transport oxygen.

28. Comparing Blackcurrant Jams
Brands
Ingredients
Nutritional Information
Cost
All natural ingredients:
- Blackcurrant Cassis
- Unsweetened Grape Juice Concentrate
- Fruit Pectin
Per 100g:
- Energy 905 kJ., 213 kcals
- Protein <0.6 g
- Carbohydrate 52 g
Sugars 52 g
- Fat 0.3 g
Saturates 0.1 g
- Fibre 2.5 g
284g for $5.40
- Blackcurrant
- Sugar
- Glucose Syrup
- Geling Agent: Pectin
- Acidity Regulator: Citric Acid
- Preservative: Potassium Sorbate
- Energy 775kJ / 183kcal
- Protein 0.8 g
- Carbohydrate 42 g
Sugars 38 g
- Fat 0.7 g
- Fibre 2.9 g
- Sodium 3.5mg
454g for $4.10