Thursday, 26 February 2015

5.2 Food Additives

Types of food additives
■ Purpose of food additive

Add flavour

Preserve the food

Improve the food texture

Supply nutrients

Enhance the colour and appearance
■ Types of food additives

Preservatives

Antioxidants

Flavourings

Stabilizers

Thickeners

Colourings
■ This video contains some basic information about food additives.


Preservative
■ Preservative

Added to food to inhibit the growth of bacteria, molds and other microorganisms.

Can increase or extend the self life of food.

Examples of food preservative:
Table salt Used to preserve fish and bacon
Sugar Used to preserve jelly, fruit jams and fruits
Vinegar Used to preserve cut fruits, vegetable and chilli
Benzoic acid (C6H5COOH) Used in jams, beer, preserved fruit, pickles, fruit juice, desert sauces and syrups
Sodium benzoate (C6H5COONa) Used to preserve fruit juice, chilli sauce and tomato sauce
Calcium propuinate ((C2H5COO)2Ca) Used to preserve bread and other baked goods
Sodium nitrite (NaNO2) Used to preserve frozen meat, tinner meat, sausages and burgers
■ This video contains information regarding food preservatives.


Antioxidant
■ Food oxidation

When kept for a long time, tends to be oxidised or deteriorate.

Oxidation of oil in food cause the food characteristic change:
Becoming rancid.
Changing the taste and color.
May be toxic.

Processes food that contains antioxidants : cakes, biscuits, margarine, deep fried food and vegetable oil.
■ This video shows why do apples turn brown when exposed to air.
■ Antioxidants

Added to prevent deterioration of fats and oils.

Prevent fats and oils from oxidation that cause rancid fats.

Vegetable oils contain natural antioxidants.

Antioxidant types:
Ascorbic acid - Helps to prevent cut and pulped foods from going brown by preventing oxidation reactions that cause the discolouration.
Citric acid - Helps to increase the anti-oxidant effects of other substances.
Butylated hydroxyanisole (BHA) - Helps to prevent the reactions that break down fats and cause the food to go rancid .

Vitamin C also an antioxidant for fresh fruits and frozen fish.
■ This video contains information regarding antioxidants in food.


Flavouring agents
■ Flavouring

Functions to:
improve the taste of food.
restore taste loss during food processing.
■ Example of most common food flavouring agents

Monosodium Glutamate (MSG)
A salt of glutamic acid.
No flavour of its own, but it bring out the flavour in meat and fish.
Produced from wheat, corn, soybeans or rice.

Aspartame
Artificial sweetener (200 times as sweet as natural sugar).
A non-carbohydrate sweetener with no caloric value.
Suitable for diebetic patient and people who want to lose weight
Not suitable for cooking food.

Asesulfame-K
Artificial sweetener used in soft drinks, yogurt and desserts.
Can be used at higher temperature.
■ This video contains information regarding antioxidants in food.


Stabilisers and thickeners
■ Stabilisers

Functions to:
make food taste smoother and finer.
help oil and water in food mixed well
make food remained in emulsify at all times

Example :
acacia gum – used in chewing gum, jelly
lecithin - in egg yolk and soy beans

Often added to food such as :
Ice-cream
Salad dressing
Milk
Creamy soup


Stabilisers and thickeners
■ Stabilisers

Added to alter the texture of food so that the food become thicker

Example of thickening agents thickeners :
pectin – used in jam
gelatin – used in yogurt
■ This video contains information regarding stabilisers and thickeners in food.


Food colouring
■ Colouring

Added to enhance the visual appearance of food

Made from natural and artificial food dyes

Colouring ingredients :
vegetables dyes
inorganic pigments
combinations of organic and metallic compounds

Azo compounds are synthetic dyes
Red, orange or yellow colours
Tartrazine which is orange colour added to orange drinks, apricot jam

Triphenyl compounds
Green, blue or purple colours
Brilliant Blue (FCF) to give colour to sweets

Other types of dye used :
Curcumin - Orange-yellow colour that is extracted from the roots of the turmeric plant.
Beta-carotene - Orange-yellow colour found in plants such as carrots, tomatoes and oranges.
■ This video contains information regarding food colouring.


The effect of food additives on health and environment
■ Food additives on health

Excessive intake of food preservatives may cause potential damage to health

Natural or vegetables additives are generally safe

Artificial and synthetic additives have toxic effect

All food additives in Malaysia should follow the Food Act of 1983
■ Effects of food additives on health

Food additives Harmful effects if taken in excess
Tartrazine Asthma
Hyperactive children
Sodium nitrite Cancer
Monosodium glutamate Have side effects :
○ difficulties in breathing
○ headaches
○ dizziness
○ vomiting
Sodium benzoate Can cause allergic reactions to our bodies
Can affect the smooth function of our nerves
Colouring substances Cancer
Migraine
Allergy
Deformed babies
■ This video contains information regarding effects of consuming food with excess food additivess.

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