Download Food Chemicals

BENZOIC ACID & BENZOATES (210 –218)
 Retards growth of bacteria and yeasts
 Occurs naturally in many foods – a similar distribution to salicylate
(but at a lower dose than as an additive)
 Common food sources:
Soft drink, cordial, fruit juice and cider
Liquid essences and syrups
Iceblocks, jelly, low joule jam, dips, pickles, olives
Fish marinades and preserves
 PABA (para-amino-benzoic-acid) can be used in vitamin supplements,
creams and sunsceen lotions
PROPIONIC ACID & PROPIONATES (280 – 283)
 Anti-fungal/anti mould food preservative, esp in bakery products
 Naturally-occurring fatty acid e.g. found in sweat, occurs as natural
preservative in Swiss cheese
 May be produced naturally in baking when whey powder is used (eg in
many “preservative-free” breads)
 Common food sources:
Bread, crumpets, muffins
Other bakery goods
Noodles
ARTIFICIAL ANTI-OXIDANTS (310 –321)
 Retard or prevent oxidation in fats and oils, and prevent discolouration
of cut fruits
 Are heat resistant, so effective in baked products
 Common food sources:
Oil, margarine, dairy blends
Salad dressings
Fried snack foods
Pastry, scones, biscuits
Note: natural antioxidants are OK – includes vitamin C (codes 300 –304),
Vitamin C derivatives (codes 317, 318) & Vitamin E (codes 306 –309)
SORBIC ACID & SORBATES (200 – 203)
 Inhibit growth of yeast & moulds, between pH 4-6. Limited effect on
bacteria, so often used as a cheese preservative (allows fermentation
by lactic acid bacteria)
 Common food sources:
Cottage cheese, processed cheeses and cheese products
(eg spreads)
Margarine, dips, yoghurts
Fruit juice, cordials, syrups
Some dried fruit (moist varieties such as figs, prunes)
Crumpets
NITRATES & NITRITES (249 – 252)
 Curing agent for meat – converts iron-containing pigments in the
flesh to stable bright-pink compounds
 Preservative against botulism bacteria
 Common food sources:
Processed meat products eg salami, fritz, corned beef, ham
and bacon
Canned cured meat products
NATURAL COLOUR ANNATTO (160b)
 Also known as bixin or norbixin
 A yellow dye from the seed coats of the tropical annatto tree
 Common food sources:
Margarine, cheese, icecream, yoghurt, custard
Noodles
Breakfast cereals
Frozen oven-bake chips
Lollies
Biscuits, cakes and baked goods
SULPHITES (220 – 228)
 An old food additive – used by ancient Greeks and Romans to
preserve wine
 Acts to prolong shelf life, slow browning reactions (to maintain colour),
stabilises vitamin C, and is an improving and bleaching agent
 Added to wine and beer to inhibit growth of undesirable yeasts
and prevent secondary fermentation
 Inhaled sulphur dioxide can cause bronchoconstriction in asthmatics,
and sulphites in food may release sulphur dioxide when eaten
 Must now be declared on food labels if present in concentrations of 10
mg/kg or more – now noticeable on many more food labels
 How much is driven off during cooking eg when glucose syrup is
boiled to make lollies?
 Common food sources:
Cordial, fruit juice, tomato juice, soft drink, wine, beer, cider
Dried fruit and products containing dried fruit, dessicated coconut
Dehydrated vegetables eg mashed potato, green peas & beans
Chocolates with soft centres, cream-filled biscuits
Commercial hot potato chips, frozen oven-fries
Commercial pre-prepared salads and dressings
Sausage mince, meat pies, frankfurters
Meat and fish pastes, prawns and other shellfish
Pickles
 Common food sources (continued):
Gelatine, vinegar, glucose syrup
Flavouring essences & syrups, fruit sauces
Flour products (bleaching agent)
Many gluten-free fours eg maize cornflour, arrowroot, potato flour
Low joule jam, lemon butter
Many medications contain sulphites, especially liquids and syrups,
injectable and inhaled medicines
ARTIFICIAL FOOD COLOURS
AZO dyes: 102, 107, 110 (yellow), 122, 123, 124, 128 (red), 151 (black)
and 155 (brown)
Non-AZOdyes: 127 (red), 132 & 133 (blue)
 Make food more colourful, or compensate for colour lost in processing
 Common food sources:
Cordial, soft drink, flavoured milk, hot chocolate mixes
Confectionary, biscuits, cakes
Iceblocks, icecream, icecream toppings
Custard powder, packet desserts, jelly, pie fillings
Gravy powders, commercial sauces, soups
Pickles, canned and glace cherries
Common food sources (continued):
Noodles, processed snack foods
Many medications eg syrups, chewable tablets, capsules
FLAVOUR ENHANCERS
Glutamates (620 –625) and Ribonucleotides (627, 631 nd 635)
 Glutamates occur naturally, but are in higher concentrations as an
additive. Mainly produced by fermentation of molasses.
 Ribonucleotides are isolated from sardines, yeast and meat extracts
 Used to enhance flavour in savoury foods –associated with a fifth taste
called “umami”
 Common food sources:
Packet soups, stock cubes & powders, gravy mixes
Flavoured noodles
Sauces
Snack foods
Many other processed savoury foods
SALICYLATE
 Salicylate occurs mainly in plant-based foods.
 Chemically similar to aspirin
 Acts like a natural pesticide, so is higher near the skin of fruit &
vegetables. Levels decline with ripening. Levels can vary
considerably, depending on growing conditions, season etc
 Common food sources:
Fruits & vegetables, herbs & spices
Honey, peppermint
Tea
 Salicylate –sensitive people may have problems with phenolic
compounds eg in “smelly” balms and liniments, perfumes,
cleaning agents etc
AMINES
 Occur mainly from breakdown of amino acids in high protein foods
 Increase with fermentation, ageing, ripening, cooking etc
 Several different amines can cause problems, including:
Histamine, Tyramine, Octopamine, Phenylethylamine,
Tryptamine, Dopamine, Noradrenalin and Serotonin
 High food sources include:
Cheese
Chocolate and chocolate flavourings
Some fruits eg banana, pineapple, raspberries, grapes, avocado
Some vegetables eg spinach, tomato, mushrooms, eggplant
Tinned fish, pork, processed meats, poultry skin
Nuts esp walnuts
Yeast and meat extracts, sauces, stock cubes, HVP/ TVP