Understanding Food Additives: Types and Functions

Food Additives

• A food additive is any substance intentionally added to food to affect its characteristics
• Food additives improve food safety, shelf life, taste, texture, and appearance.

Definition (European Legislation)

• Food additives are defined as substances not normally consumed as food itself, nor used as characteristic food ingredients
• They may or may not have nutritive value.
• Food additives are intentionally added for a technological purpose during manufacture, processing, preparation, treatment, packaging, transport, or storage.
• Food additives or their by-products may become components of such foods, directly or indirectly.

Classes of Food Additives

• Sensory improvers enhance flavors, colors, and overall sensory experience
• Preservatives extend shelf life by inhibiting microbial growth
• Antioxidants prevent oxidative deterioration
• Process aids facilitate manufacturing and improve food processing

Sensory Improvers

• Flavors enhance taste and smell
• Coloring gives food an attractive look
• Acidulants sharpen flavors
• Sweeteners enhance sweetness
• Flavor enhancers sharpen existing flavors

Flavors

• Flavors, enhancers, and fragrances play a vital role in imparting taste and smell to food
• Flavors can be artificial or natural.
• Flavorings may be nature-identical compounds from chemical synthesis or isolation.
• Flavor enhancers enhance or sharpen existing flavors.
• Examples include Monosodium glutamate (MSG), monopotassium glutamate (MPG), calcium diglutamate (CDG), and monoammonium glutamate (MAG).

Colorants

• Food colorants are not always added for nutrition but to improve appearance.
• Colouring/retention agents give food an attractive look, replace lost color, and prevent fading during preparation, transportation, or storage.
• Some agents are natural while others are chemically/artificially prepared.
• Natural agents are carotenoids, anthocyanins, and betalains
• Chemical agents are azocompounds, amaranth, brilliant blue, indigo carmine, new red, sunset yellow, tartrazine, and allura

Natural Food Colorants

• This class of compounds originating from plant sources
• Such as Anthocyanins from red fruits, Betanin, Caramel pigment, Carotenoids, Lycopene Lutein, Green pigments (chlorophyll), and Curcumin

Nature-Identical Food Colorants

• These compounds are synthesized to match the chemical identity of natural colorants.
• Examples include carotene, canthaxanthin, and riboflavin.
• The majority of colors, both natural and nature-identical colors, are hydrophobic
• They are made hydrophilic by converting into sodium or potassium salt forms
• Alternatively they can be dissolved in a hydrophobic medium like oil.

Synthetic/Artificial Food Colorants

• Are molecules synthesized through chemical processes, capable of imparting colors to foods
• Examples include tartrazine and carmoisine
• The majority of synthetic colorants are hydrophilic

Food Acids and Acidity Regulators

• Acids sharpen flavors and act as preservatives + antioxidants.
• Acetic acid (vinegar), citric acid, tartaric acid, malic acid, fumaric acid, and lactic acid are examples.
• Acidity regulators are substances such as organic/mineral acids, bases, neutralizing agents, buffering agents.
• These regulators are added to adjust and control the pH of foods.

Citric Acid

• Citric acid is normally prepared by fermentation processes of carbohydrates using aspergillus niger.
• Citric acid is produced from molasses or citrus fruits.
• Functions include sharpness, preservative qualities for foods like meat, and antioxidant properties, especially in fatty foods

Lactic Acid

• Lactic acid is produced via fermentation processes, but can also be made synthetically.
• It is found in dairy products, sweets, and baked goods.

Acetic Acid

• Acetic acid is found in vinegar and is produced industrially through synthetic and bacterial fermentation
• Used mainly as a flavoring agent
• Used as a preserving agent due to antimicrobial properties.

Malic Acid

• This acid is found in fruits like bananas, apples, and tomatoes
• Found in low-energy drinks.

Fumaric Acid

• It has a strong flavour and low solubility in aqueous media.
• Fumaric acid is synthesized using malic acid.

Tartaric Acid

• Tartaric acid is used as emulsifiers in baking and confectionaries.
• Tartaric acid is synthetically produced using maleic anhydride, and it can be obtained from wine by extraction.

Phosphoric Acid

• Phosphoric acid’s salts provide a buffering environment in foods, for example in baking powders

Sweeteners

• These are added to foods mainly for flavoring purposes and also as supplements
• Nutritive sweeteners are sugar alcohols like glycol, glycerol, erythritol, threitol, and arabitol.
• Honey is a natural sweetener.
• Synthetic sweeteners is another type

Synthetic Sweeteners

• Aspartame
  • Methyl ester of some amino acids
  • 200 times sweeter than table sugar (sucrose)
• Sucralose
  • A chlorinated sugar
  • 600 times sweeter than sucrose and is heat stable
  • Used in fried and baked products, beverages, chewing gums and frozen desserts
• Acesulfame K (950)
  • 130-200 times sweeter than sucrose

Preservatives

• Food preservatives are substances that are added to food to prevent spoilage and extend shelf life.
• They inhibit the growth of microorganisms, such as bacteria, yeasts, and molds.
• Preservatives also prevent food browning, discolouring, or developing off-flavors.
• Examples are Benzoates (like sodium benzoate), Nitrites (like sodium nitrite), Sulphites (like sulphur dioxide)

Examples of Natural Preservative Compounds

• Lactoperoxidase found in milk
• Lysozyme found in egg white
• Saponins and flavonoids from herbs and spices
• Bacteriocins extracted from probiotic lactic acid bacteria

Sodium Metabisulfite

• It is a food additive that is used as a preservative, bleaching agent, and relaxing agent in food processing.
• It is Soluble in water and ethanol

Antioxidants

• Food antioxidants play an important role in the food industry for neutralising free radicals.
• They donate their own electrons to free radicals without becoming free radicals, terminating the radical chain reaction.
• Antioxidants reduce oxidative deterioration of rancidity, loss of flavour, colour and nutritive value.
• Fats, oils, flavouring substances, vitamins and colors can spontaneously oxidise upon exposure to air

Factors Influencing Deterioration

• Deterioration rates depending on natural antioxidants, oxygen availability, substance oxidation sensitivity, temperature, and light
• Ascorbic acid removes oxygen by self-oxidation
• Tocopherols, Gallic acid esters, BHA and BHT interfere oxidation mechanisims
• Sequestering agents (linking ions), like citric acid, have synergist effects
• Synthetic antioxidants BHA, BHT, and gallic acid esters are restricted

Processing Aids

• Flour Treatment/Improving Agents are properties that need to be improved like bakery products
• Properties improved for colour, texture, softness, and fineness of the grains
• Flour Treatment uses both maturing and bleaching agents.
• They improve flour properties for bakery products.

Flour Maturing Agents

• They are food additives that improve baking performance by strengthening the gluten network.
• This allows it to hold more gas so it can produce a higher-rising loaf of bread
• Examples include Ascorbic acid (vitamin C), Azo-dicarbonamide (ADA), Ammonium persulfate, as well as Potassium bromate

Flour Bleaching Agents

• Flour Bleaching Agents are also food additives that improve improve its baking performance.
• They make it appear whiter.
• This is done by oxidizing flour pigments, which become colorless.
• Examples include Benzoyl peroxide, Calcium peroxide, Chlorine gas, and Nitrogen dioxide

Anticaking Agents

• Anticaking Agents are used to prevent granulated food items from clumping
• These include Calcium silicate, Magnesium carbonate, Baking soda, Sodium ferrocyanide, kaolin, talc and bentonite.
• They have an affect on quality of food - it can result in physical and morphological changes.
• This usually happens to powdered food materials such as milk powder, powdered sugar, tea and coffee,

Humectants

• Humectants is used to keep products moist in the food industry, preventing any loss of quality
• Used in food items such as cream, chocolate and cheese, in which additives preventing foodstuffs from drying
• They perform the function of moisturisers by attracting water molecules such as Glycerol, Sorbitol and Mannitol

Emulsifiers

• Emulsifiers are needed because there is challenge for food industries to form homogeneous mixtures iof immiscible food components
• Food emulsifiers are chemical molecules made up of hydrophilic and a hydrophobic part
• These compounds can be Oil in Water, Water in Oil and Air in Water

The Role of Emulsifiers in Foods

• Improve food palatability
• Maximise the volume and aeration of food items
• Reduce the stickiness
• Enhance food flavor
• Improve the textural properties of foods

Commercial Emulsifiers Are Used in Different Foods

• Lecithin is used in mayonnaise to help stabilize the emulsion of oil and eggs.
• Mono- and di-glycerides are used in margarine to help keep the water and oil from separating.
• Polysorbates are used in ice cream to help create a smooth and creamy texture.
• Xanthan gum is used in sauces and dressings to help keep them smooth and creamy.

Stabilisers, Gums, Thickeners and Gelling Agents as Food Additives

• Stabilisers are additives that are incorporated into food items to give them a firmer texture
• The molecules used as stabilisers, thickeners or gelling agents are macromolecules which, when dissolved or dispersed in aqueous media, are capable of causing an increase in the viscosity or gel formation

Most Widely Used Stabilisers

• Most widely used stabilisers in the food industry are: Carrageenans, Alginates, Agar, Guar gum, Arabic gum, Xanthan gum, and Carboxymethylcellulose.

Functions for Food Additives

• Prolong shelf life
• Functional property provision and improvement
• Process facilitation
• Enhance consumer acceptance
• Reduce wastage and make food more readily available

Identification of Food Additives

International Numbering System (INS)

• Numbers provide a systematic way to identify food additives
• They are assigned by the Codex Alimentarius Commission.
• Commission is a joint committee of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO)

INS Numbers

• These are three or four digits long and may have an alphabetical suffix
• The suffix indicates different forms of the same additive

European (E) Numbers

• A numbering system employed in the European commission in the 1960s to identify food additives, helping consumers to understand what is in their food

Explore the world of food additives, substances intentionally added to food to enhance safety, shelf life, taste, texture, and appearance. Learn about their definition according to European legislation and the various classes, including sensory improvers, preservatives, antioxidants, and process aids.