Food Additives Additives What do we eat Fresh

Food Additives

Additives [ What do we eat? [ Fresh food versus processed food. [ Changing patterns of food consumption. [ Longer storage and processing [ Need to maintain food quality

What are additives? [ Substances added to food that are not naturally present [ Not nutritive [ Original aim usually preservation [ Later to enhance food appearance [ and enhance food quality

Types of Additives and their Functions

Food Regulation [ US GRAS system [ Generally Recognised As Safe [ Introduced in 1958 to approve established food ingredients [ New additives must be approved by FDA [ Delaney Clause to prohibit any substance known to cause cancer

Additive Testing [ Relies on animal tests to NOEL [ No Observable Effect Level = highest dose of additive with no effect on animal [ Reduced by a factor of 100 to give safety margin for humans

E number system [ European system for approved food additives [ E classification shows the additive is safe for use in food [ Internationally recognised and also used in other countries

E numbers

Earliest Additives [ Preservatives [ Sodium Chloride, Salt [ Used for 10, 000 years to preserve meat products [ Salt reduces water availability for bacteria to grow [ Crude salt is contaminated with sodium nitrate [ Additional use of smoke

Traditional Additives [ Used for thousands of year Y Salt and saltpetre Y Smoke Y Honey Y Vinegar Y Herbs & Spices Y Natural food colourings Y Calcium carbonate

E 250 Sodium Nitrite [ Sodium nitrate contaminant of crude salt [ Found to cause pinkish colour in meat [ Sodium nitrite more effective [ On high temp cooking can be converted to carcinogenic compounds nitrosoamines. [ Potent inhibitor of anaerobic metabolism [ Prevents growth of major food pathogen [ Clostridium botulinum

Clostridium botulinum [ Common soil bacteria [ Anaerobe can only grow well when no oxygen present [ Spores heat resistant to 120°C for 3 mins [ Bacteria produces protein toxin [ 1µg fatal, respiratory paralysis and cardiac failure

Meat colour [ Fresh meat ~ purplish red Y Exposed meat, bright red oxymyoglobin Y Later turns to metmyoglobin, gray or brown [ Nitrite reacts to form nitrosomyoglobin Y After Y cooking – nitrosohaemochrome pinkish red in colour

Cured meat [ Pickled in salts, Y Salt, sodium nitrite, ascorbic acid, sugar Y Meat submerged in strong solution Y Or injected by machines with multiple needles Y 10 days at 4°C

Smoking [ Wood fire, produces anti bacterial compounds [ Provides surface coating and protection [ Colour and flavour [ Hams, heated to 60°C Y Not sterile, must be refrigerated, Y But can be eaten raw [ Bacon, only heated to 52°C Y Cannot be eaten raw

Sausages [ Ground meat, low quality off-cuts Y Natural casing, eg. sheep intestine Y Stuffed + spices, salt, sugar, ice Y Sodium nitrite to inhibit Clostridium botulinum

Frankfurters, hot dogs [ Meat comminuted Y Ground very finely to form meat emulsion Y 30% fat, 10% water Y stuffed in cellophane casings to form links Y smoked or cooked to 75°C Y De-skinned, passed through hot water and skins peeled off by machine.

Spoilage [ Become slimy Y Surface [ Turn growth of yeasts and bacteria green Y lactobacter releasing hydrogen peroxide Y Reacts with nitrosohaemochrome Y oxidises it to a green colour

More Preservatives [ E 200 Sorbic Acid, soft drinks, yoghourt. [ E 210 Benzoic acid, jams, creams [ E 220 Sulphites, SO 2 wine, vegetables, drinks Diphenyl, fruit Nisin, cheese Hexamine Fish Propionic acid Bread [ E 230 [ E 234 [ E 239 [ E 280

Antioxidants [ Chemical preservation [ Most important for fats Y E 300 Ascorbic acid (vitamin C) Y E 306 Tocopherol (Vitamin E) Y E 320 BHA meat products, dairy products Y E 321 BHT meat products, dairy products

Flavour [ Artificial Sweeteners Y sucrose Y cyclamate Y saccharin Y aspartame Y sucralose Y alitame Y thaumatin 1 30 300 180 600 2000 2500

Artificial Flavours [ Mimics of natural flavours using complex mixes of pure chemicals [ Synthetic banana flavour amyl acetate Y amyl butartae Y ethyl butartae Y isoamyl acetate Y isoamyl butarate Y linalool Y + 15 others in lesser quantities Y

Flavour enhancer [ E 621 monosodium glutamate [ amino acid - glutamine

19 th century [ Increased urbanisation & food processing Y Adulteration Y Use of cheap substitutes Y Colour & flavour enhancers [ Sometimes Y 1857 dangerous survey of confectionary found colours: V Lead chromate V Mercuric sulphide V Copper arsenite

Food Colours [ Preserved Vegetables Y Chlorophyll, green pigment in plants is unstable Y Green colour from copper salts due to cooking under acid conditions in copper pans

Confectionary [ Colouring to enhance consumer appeal Y Natural Y Inorganic Y Synthetic

Natural Colours [ Caramel, brown from burnt sugar, Y most widely used colour, Y not always classified as an additive [ Carotenoids, orange/yellows [ Anthocyanins, reds & blues [ Betalaines, red/purple [ Turmeric, root of turmeric plant, yellow [ Cochineal, insects from cactus, scarlet

Synthetic Colours [ Yellow Tartrazine Y Sunset yellow [ Red 2 G Y Ponceau 4 R Y Amaranth E 102 E 110 E 128 E 124 E 123 [ Blue Brilliant Blue FCF E 133 [ Green Food Green S [ Brown Chocolate Brown E 155 E 142

Dye problem [ Many organic chemicals with bright colours found to be carcinogenic [ Flat shape allows them to interfere with DNA helix [ Usually found by effects on people making them not those eating them [ e. g. Butter yellow [ Not allowed to be used in foods

Bread [ Flour whitening Y calcium [ Anti carbonate caking agents Y ammonium [ Dough citrate enhancers Y stearate [ Leavening Y baking agents powder

Emulsifiers [ Stabilise mixtures of food components [ Oil and water [ Natural emulsifier - E 322 lecithin [ Synthetic YE 471 Glyceryl monostearate Y E 442 Ammonium phosphatide Y E 435 polysorbate

Thickeners [ Non-starch polysaccharides [ Bind water to form gels [ Algal origin Y Alginates, agar, carrageenans [ Plant Y origin Guar gum, Locust Bean gum [ Modified Y methyl cellulose [ Bacterial Y celluloses, origin Xanthan gum

Is It Safe [ Better than the alternative [ Food degradation by biological or chemical action - very unsafe!