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Food Additives Throughout history, mankind has needed to prolong the shelf life of food, modify its organoleptic characteristics or stabilize its physical properties, with the aim of surviving periods of shortage, drought or winters. In the past, the classification of additives was less common and food consumption was seasonal, but with the development of agriculture and livestock, mankind began to manipulate food in order to preserve them better and transform them into more durable and stable products. The first techniques developed were based on physical treatments, which were sometimes combined with chemical treatments. Some of these treatments are still currently used, for example, drying, salting, smoking, and freezing, among others. Food additives are one of the great technologies that have been developed in terms of food preservation and transformation. Due to massive urbanization and the rhythm of life in the twentieth century, it has become necessary to use food additives to adapt products to current needs. Without additives, many foods could not be manufactured or even consumed. Today, additives are part of our daily lives, since virtually all beverages and processed foods we consume contain any of these substances. However, the incorporation of additives into the food industry’s products is a controversial issue due to both ignorance and concern on the part of consumers. On one hand, there is ignorance in the classification of additives and their types, and on the other, there is concern about the possible impact of certain additives on human health. According to the Codex, international food standards proposed by FAO and approved by WHO, a food additive is defined as “any substance which is not normally consumed as a food, nor is it used as a basic food ingredient, having a nutritional value or not and whose intentional addition to the food for technological purposes in its manufacturing, processing, preparation, processing, packaging, packaging, transport or storage phases, results or can reasonably be expected to result in itself or its by-products in a component of the food or an element that affects its characteristics.” Main characteristics of food additives In the food industry, for a substance to be admitted as an additive and to be used, it must overcome toxicological controls, be chemically characterised and demonstrate that its use provides consumer benefits and/or technological benefits. The 7 main functions of the additives are: Ensure the safety and edibleness of the food. Preserve or increase the nutritive value of the ingredients. Increase stability or improve organoleptic properties. Prolong the shelf life of the food and contribute to its conservation. Make possible the availability of food out of season. Facilitate the manufacturing processes of the products. Provide food for groups of consumers with particular dietary needs. Classification of food additives The following classification of additives is based on criteria on their technological functions.
However, it is necessary to emphasize that there are other classifications based on the origin (natural or synthetic) or the type of additive.
- Stabilizers of physical characteristics Emulsifiers: substances that allow the maintenance or formation of a homogeneous mixture of two or more non-miscible phases. For example, water and oil. Thickeners: macromolecules that preserve the textures of foods such as viscosity or gelling effect. For example, adding E-406 (agar-agar) to a jam preserves its texture. Anti-caking agents: a substance that prevents the formation of clumps or lumps that affect product homogeneity. They are usually used in soups, sauces, juices or dairy products. Acidity correctors: substances that control or alter the pH of food. Inadequate control can lead to the proliferation of undesirable bacteria in the food which could suppose a health risk.
- Inhibitors of chemical and biological alterations Antioxidants: they are additives that are added mainly to fatty ingredients to delay or prevent the rancidity of foods due to oxidation. There are two types of antioxidants on the market: natural and synthetic. Conservatives: substances that when added protect food against deterioration caused by unwanted microorganisms. They are often used in food containing water, such as bakery, pastries, dairy, beverages or meat products.
- Modifiers of organoleptic characters Colouring agents: substances used to modify or stabilise the colouring characteristics of a food. Colour in food is an aspect that is associated with the quality of food and is related to taste and smell. The use of dyes in food goes back to ancient civilizations; the use of saffron or cochineal for colouring have a long tradition which continues to today. Flavour enhancers: substances that enhance the taste and / or aroma of a food without giving its own flavour. They are widely used in sauces and soups. Monosodium glutamate is one of the most used in processed foods. Sweeteners: these additives are used to provide sweet taste or to mimic flavours. Its aim is that the flavour is the most similar to the common sugar and resist similar treatments in which sugar is used. They are very important in products for diabetics or low calorie products. Aromatic substances: are substances that provide a new aroma and / or correct the aroma of food and beverages. It is possible to obtain them from extracts of vegetable origin.
- Improvers and correctors They are additives that are used in baking, wine making, or to regulate the maturation of dairy products, such as cheese or meat products. As mentioned above, there are natural and synthetic additives that are titrated according to the ADI (acceptable daily intake) and based on available toxicological data. Each additive
Need for food additives · It provides protection against food spoilage during storage, transportation, distribution and processing. · It is included in the preparation of convenience foods like jams and jellies. · To fortify or enrich the foods. · It is used to add colour, flavour, and firmness and retards or hastens chemical reactions in food. · To maintain the nutritional quality of food. · Used as a preservative and colouring agent. The E numbers are categorized as follows: x E100–E199 (colours) x E200–E299 (preservatives) x E300–E399 (antioxidants, acidity regulators) x E400–E499 (thickeners, stabilizers, emulsifiers) x E500–E599 (acidity regulators, anti-caking agents) x E600–E699 (flavour enhancers) x E900–E999 (surface coating agents, gases, sweeteners ) x E1000–E1999 (additional chemicals) Classification of food additives The food additives can be classified as following: · Preservatives · Colouring agents · Antioxidants · Artificial sweeteners · Flavouring agent · Emulsifiers, Stabilizers and Thickeners · Flour improvers · Humectants · Curing agents · Chelating agents · Leavening agents
- Preservatives
Preservatives are compounds used to prevent and retard the microbial spoilage of food. They are classified in to · Class I and · Class II preservatives. Class I preservatives: They are natural substances and their addition of it to food is not restricted. Eg. Salt, sugar, honey, vegetable oil, spices etc. Class II preservatives: They are chemical substances which should be included in food in a restricted quantity. Eg. Benzoic acid, Sorbic acid etc.
- Colouring agents It is a dye, pigment or substance to impart colour in the food. It is classified into · Natural colours ( Naturally available Eg. Turmeric) · Synthetic colours ( Synthesised from fruits, vegetables and chemicals Eg: Tartrazine, sunset yellow)
- Artificial sweeteners These are said to be sugar substitute which contains less energy and not produced naturally. Eg. Saccharin, Aspartame, Dulcin etc.
- Anti Oxidants Antioxidants are added to oils and fats to prevent oxidative rancidity Eg. Ethyl Propyl, Octyl Gallates etc
- Flavouring agents They form a divergent group of organic compounds both natural and synthetic in nature. Eg. Menthol, vanillin etc.
- Emulsifiers, Stabilizers and Thickeners A variety of organic compounds form the group of emulsifiers, stabilizers and thickening agents Eg. Guar gum, Gelatine, Agar-agar etc.
- Humectants These are moisture retention agents. It controls viscosity, texture, bulking, retention of moisture, reduction of water activity, control of crystallization and improvement of softness. Eg. poly hydroxyl alcohols.
- Flour improves these are bleaching and maturing agents used to bleach and mature the flour. Eg. Benzyl peroxide.
- Curing agents these are additives to preserve meat, give them desirable colour, flavour, and discourage microbial growth. Eg. Sodium nitrite10. Chelating agents are antioxidants. They serve as scavengers of metals which catalyze oxidation. Eg. Ethylene Diamide Tetraacetic
- Leavening agents Leavening agent causes the expansion of dough and batter by releasing gas and giving porous structure. Eg. Yeast, Baking powder and baking soda Harmful effects of food additives · Hydrogenated Fats— It cause cardiovascular disease and obesity · Artificial Food Colors— It leads to allergies, asthma and carcinogenic · Nitrites and Nitrates— Carcinogenic · Sulfites (sulfur dioxide, metabisulfites, and others)— It leads to allergy and asthmatic reactions
Annatto, a reddish-orange dye made from the seed of the Achiote. A green dye made from chlorella algae. Cochineal, a red dye derived from the cochineal insect, Dactylopius coccus. Betanin extracted from beets. Turmeric Saffron Paprika Elderberry To ensure reproducibility, the coloured components of these substances are often provided in highly purified form, and for increased stability and convenience, they can be formulated in suitable carrier materials (solid and liquid). Artificial colouring The colours below are known as “Primary Colours”, when they are mixed to produce other colours, those colours are then known as “Secondary Colours”. *Brilliant Blue, E133 (Blue shade)
- Indigotine, E132 (Dark Blue shade)
- Fast Green, E143 (Bluish green shade)
- Allura Red AC, E129 (Red shade)
- Erythrosine, E127 (Pink shade)
- Tartrazine, E102 (Yellow shade)
- Sunset Yellow, E110 (Orange shade) Dyes and Lakes Colour additives are available for use in food as either “dyes” or “lakes”. Dyes dissolve in water, but are not soluble in oil. Dyes are manufactured as powders, granules, liquids or other special purpose forms. They can be used in beverages, dry mixes, baked Goods, confectionry, dairy products, pet foods and a variety of other products. Lakes are the combination of dyes and insoluble material. Lakes tint by dispersion. Lakes are not oil soluble, but are oil dispersible. Lakes are more stable than dyes and are ideal for colouring products containing fats and oils or items lacking sufficient moisture to dissolve dyes. Typical uses include coated tablets, cake and donut mixes, hard candies and chewing gum. Artificial colours consist of water soluble synthetic dyes or the aluminum salts of these dyes, called “Lakes.” These seven synthetic dyes and their salts are deemed acceptable by most Food authorities for use in food. Blending the seven produces a wide spectrum of colour, including purple, black, brown, and variations of the primary colours. Dyes display colours when dissolved in the aqueous phase of a food product. However, their solubility varies with temperature and often with the solute. Although at typical usage levels this will not ordinarily affect the finished product, it could make a difference when colour solutions are prepared. If the temperature of the solute changes, all the dye may not be in solution, and this could affect the colour of the finished product. The Lakes are insoluble in most solvents and instead colour by dispersion. They are used in low moisture, often high-fat applications, but are not fat soluble. They may bleed color
slightly in water, but in most applications they minimize colour bleed into adjoining areas. The shades produced depend on the method of production and to some extent on particle size. Lakes are more resistant than dyes to fading when exposed to high heat and light.Dyes go into solution and function on a molecular level. Lakes are different because the particles are dispersed. Particle size, particle shape and how well the particles are dispersed in the finished product all influence the outcome. In some cases, simply increasing the shear during dispersion may intensify the colour. A number of food colourings are obtained in either powder or liquid form. it can be divided into two categories: Natural colouring agents Artificial colouring agents NATURAL COLOURING AGENTS: Cochineal: It is a red colour, produced from the cochineal beetle. it is used in pastry and confectionery work. Green colouring: This can be made by mixing indigo, and saffron, but chlorophyll, the natural green colouring of plants, such as in spinach, may also be used. Indigo: This is the blue colour seldom used on its own, but which, when mixed with red, produces shades of mauve. Yellow colouring: a deep yellow colour can be obtained from turmeric roots and is prepared in the form of a powder mainly used in curry and mustard pickles. Yellow is also obtained by using egg yolks or saffron. Brown: Brown sugar is used to give a deep brown colour in rich fruit cakes, it is also added to enhance the flavour. Blackjack or Browning: Blackjack or commercial caramel is a dark brown, almost black liquid and is used for colouring soups, sauces, gravies, aspics and in pastry and confectionery. Chocolate: this can be obtained in liquid or powder form, and is used in pastries and confectionery. Coffee colour: This is usually made from coffee beans with the addition of chicory. ARTIFICIAL COLOURING AGENTS A large range of artificial colours are also obtainable, they are produced from coal tar and are haffilles. some mineral colours are also used in foodstuffs. All colouring must be pure and there is a list of those permitted for cookery and confectionery use
This is a natural flavouring substances obtained by subjecting untreated and uncontaminated hardwood, including sawdust and woody plants, to one or more of the following processes are used such as controlled burning, dry distillation at appropriate temperatures, and or treatment with superheated steam and obtaining fractions which have the desired flavour potential. salt is certainly the most essential element, that is used mostly in all the savory dishes and sometimes sweet courses. Extracts and essences, wines, spirits, beer and cider, liqueurs, and cordials, vinegar and marinades also play an important role in flavoring foods.
OTHER FLAVOURING AGENTS
Basically, these are called seasonings: for example, red chilli powders, mustard, pepper and nutmeg, basil, thyme and cardamom etc.
OBTAINED FROM PLANTS:
Fruits: Mango, Strawberry, Nutmeg, dry fruits etc.
Flowers: Rose etc
Stems: Cinnamon sticks etc
Leaves: Basil, Thyme, Rosemary, etc
OBTAINED FROM ANIMALS:
Milk Cream Yogurt The flavor of any food depends upon minute quantities of 100 or more chemicals that are present in food. These flavoring components are present in concentrations ranging from a few ppm to 0.1 percent. Classification of flavors: Natural Flavours: Herbs, Spices, Aromatic seeds, Fruits, Vegetables Processed flavours: Fermented, Baked, Toasted, Roasted, Cara-melized Added flavours: These are two types: Natural extracted flavours: Essential oils: Clove oils Essences: Vanilla Extract: Yeast and Beef b Synthetic Flavours: Fruits flavours (blend of esters): Banana, peach,
pineapple and vanillin Savoury flavours: Chicken, Onion and Smoked Some plant produce flavours: Herbs: Basil. Parsley, celery, thyme, mint, etc. Fruits: Orange, lemon, apple, banana, strawberry, Pineapple, etc. Spices: Cardamon, clove, turmeric, peppercorns, etc. Vegetables: Mushrooms, corn, peas, onion, garlic, cabbage, turnips, etc. Aromatic seeds: Aniseed, cumin, fennel, dill, caraway, etc. The aroma of onion, garlic, cabbage, etc. is mainly due to sulphur – containing compounds. These vegetables should not be overcooked. Other flavouring components in vegetables are methanol, acetone, propanal, etc. Flavour Compounds The substances mainly responsible for the aroma of food products are volatile compounds. These may be aliphatic esters, aldehydes, or ketones and are present in fruit and other natural foods in very low concentration: many thousands of natural flavouring compounds are known and in any one food there may be hundreds of these present. Some of the important groups of flavouring compounds are as under: Flavonoids: Flavonoids are responsible for the flavor of many fruits, e.g., orange, lemon and grapefruit peels contain a number of flavanone glycosides. Among these, hesperidin (orange and lemon) and naringenin (grapefruit) are the most common. Hesperidin is quite tasteless, whereas naringenin has an extremely bitter taste. Terpenoids: Terpenoids are ubiquitous in plant foods. They are the major components of citrus oils and contribute to the flavor of citrus fruits. Limonene, a monoterpene hydrocarbon, possessing a lemon-like odour constitutes approximately 90 percent of most citrus oils. Naturally occurring oxygenated terpenes (mainly alcohols, aldehydes and ketones) provide the characteristics flavor of individual citrus species, e.g., neral and geranial of lemons and nootkatone (bicyclic sesquiter-pene) of grapefruit. In the presence of air or dissolved oxygen terpenes undergo struct-ural changes and hydration, hence citrus juice concentrates prepared by low-temperature vacuum evaporation are superior in flavor than those processed at high temperatures. Juices of certain varieties of orange and grapefruit become bitter when kept at room temperature for some time, due to the formation of the bitter limonin from its nonbitter precursor (limonin monolactone) by the action of the organic acids present in the juice. This can be prevented by removing the precursor by exposing the fruits to ethylene before juice extraction, or by the addition of a specific enzyme to the juice to degrade limonin. Sulphur compounds: Certain volatile sulphur – containing compounds possess powerful and distinctive odours which contribute to both the pleasant and unpleasant aroma of many foods, e.g., vegetables belonging to the genus Allium (onion, garlic) and Brassica (cabbage, cauliflower, Brussels sprouts, broccoli). Vegetables of the Brassica family contain the sulphur compounds S–methylcysteine sulphoxide and thioglucosides. On cooking the vegetables, the former is converted into dimethyl sulphide which is partly responsible for odour. However, the predominant odour is
Among the phenols, phenol itself contributes to the aroma of some cheeses. Vinyl guaiacol is present in many foods, eugenol is an important component of oil of cloves but is also widely distributed and thymol is responsible for the odour of tangerine. Flavour Additives In the case of certain flavours the substances responsible for them are difficult or impossible to isolate from natural sources such as strawberry, cherry and beans. These natural flavours have, therefore, to be imitated as far as possible by mixing a number of flavouring agents, natural and / or synthetic. The success of such imitation is more a matter of art than of science and is judged by the consumer preference for the flavoured product. Both essential oils and synthetic flavouring agents must be used in accordance with good manufacturing practice the salient points of which are: (i) The amount added shall not exceed that reasonably required to accomplish the intended effect. (ii) Substances that may become part of the food as a result of manufacturing shall be kept as low as possible. (iii) The substance shall be of a good grade. Moreover, a flavouring agent may not be added to a food for which there is a standard, unless the standard includes it. The following chemicals are used as flavor additives: Monosodium glutamate (MSG): It is commonly known as Chinese salt or aji-no-moto. Worldwide used as flavor intensifier in soup, sauces, gravies, tastemakers and flourings, canned and frozen vegetables, meat, poultry and combination dishes. A level of 0.05-0.8% by weight in foods gives the best flavor enhancement and excessive use decreases the palatability of food. Under the PFA (Prevention of Food Adulteration) Act, MSG has been banned in foods meant for infants below 12 months of age, and should not exceed 1 percent weight in foods meant for adults. Nucleotides: Its flavor enhancers widely present in plant and animal cells. It is used in processed foods such as potato, chips, peanuts, dry and canned soups, sauces, ketchups, sausages, canned vegetables and meat. The quantity of nucleotide added is very low. They are 50 to 100 times stronger than MSG. Maltol: It is used as a flavor enhancer for sweet flavours. It is found in several plants and is formed when cocoa, coffee and malt are roasted and in bread. It is synthesized from soya bean protein fermentation and is used as a fragrant, caramel like flavor for addition to fruit- based products, ice cream, chocolates and candies. It imparts a ‘freshly baked’ flavor to bread and cake. It also used in cookies, beverages, instant pudding mix and soup mixes at levels ranging between 50-300ppm. Salt: Salt is used in food for its flavor, as a preservative and as a dietary constituent. The main role of salt in food is for salty taste, flavor intensification and as a digestive stimulant. It is used at 2 percent level. Sodium restricted flavouring: When salt is restricted on health grounds because of hypertension, oedema, kidney disorder, etc. the flavor of food can be improved by using herbs and spices such as pepper, dry mustard, paprika, lime juice, mint, celery, onion, ginger, garlic and bay leaf. Salt substitutes are salts which do not contain sodium but contain potassium or ammonium instead, such as potassium chloride and ammonium chloride.
Popular herbs and spices: Herbs Description Herbs Descriptio Basil Small leaves with pungent flavor Ajwain Small roun Bay leaf Dried aromatic leaf of the laurel tree Allspice Berries wit cinnamon Aniseed Seeds loo sweet liqu Star anise Pretty star Chervil Looks like parsley with delicate stem and soft, almost wilting leaves; has faint flavor Asafetida Strong – f smell Chive Tender green shoots with mild onion and scallion flavor Cardamom Black larg pleasing w Coriander/cilantro Looks like parsley; piquant taste and intense flavor with a fresh pungency Chillies Numerous chillies wit Curry leaves Long slender shiny dark green leaflets: strong warm spicy aroma curry flavor Cinnamon Delicate in small ever Dill Fine feathery green stands with sweet aromatic flavor of caraway and lemon Cloves Dried unop pungent fl Fennel Fine wispy leaves with mild aniseed and dill flavor Coriander seeds Yellowish pleasant f Horseradish Long tapering root with powerful smell and fiery taste Cumin and caraway seeds Caraway s shaped se sharp, and
Pomegranate seeds Dried seed used for s Saffron Stigmas o used for d colour; ver Tamarind Sour, fruity Turmeric Rhizome w curry pow Some flavours in food Natural flavours Foodstuff Principal flavouring agent Mint Menthol Thyme Thymol Cloves Eugenol Pepper Piperidine Butter Diacetal Orange Limonene Lemon Citral
Garlic Diallyl disulfide Turmeric Curcumin Synethetic fruit flavours Flavor Chemical (mixtures of este Banana Ethyl butyrate +amyl acetat Peach Benzaldehyde, benzyl alcoh Apple Ethyl acetate Pineapple Pentyl acetate Strawberries Methyl and ethyl acetates p Flavor enhancers Foodstuff Flavouring compound Chicken soup Monosodium glutamate Mushrooms Nucleotides, i.e., GMP Diso Raising agents
Quick revise
We use raising agents to add gas to dough and other mixtures so they can expand and rise when heated.
Bicarbonate of soda, when heated breaks down to produce carbon dioxide bubbles that
droplets of water dispersed in oil. Within the emulsion, there is a continuous and dispersed phase. In an oil-in-water emulsion, the continuous phase is the water and the dispersed phase is the oil; conversely, in a water-in-oil emulsion, the oil is the continuous phase. Emulsions also can be made by applying mechanical force from a blender or homogenizer, which breaks down the dispersed phase into tiny droplets that become suspended in the continuous phase. Low-fat spreads, ice cream, margarine, salad dressings, and many other creamy sauces are kept in stable emulsions with the addition of emulsifiers. These additives also are widely used in other foods such as peanut butter and chocolate. “Emulsifiers enhance the structure of baked goods by increasing whip-ability of batters, conditioning of dough, and helping foods like pasta be more resistant to overcooking. Commonly used emulsifiers in modern food production include mustard, soy and egg lecithin, mono- and diglycerides, polysorbates, carrageenan, guar gum and canola oil. Lecithin in egg yolks is one of the most powerful and oldest forms of an animal-derived emulsifier used to stabilize oil in water emulsions, for example, in mayonnaise and hollandaise sauce. Emulsifiers are required by law to be included on a food’s ingredient list. ANTI-OXIDANTS Food additives, especially antioxidant preservatives, are key elements in the food industry and production. Food antioxidants can be natural products such as extracts and purified natural metabolites, or synthetic compounds. They act as radical scavengers, chelators, quenchers, or antioxidant regenerators. Generally, food antioxidants target the preservation of food without altering its taste and color. Synthetic antioxidants are cheap, easy to use,
and efficient as preservative agents; however, consumers tend to seek natural antioxidants. This chapter focuses on the different functional antioxidants such as polyphenols, and tocopherols that can be used as food additives. These compounds are characterized by different chemical structures and different mechanisms of action. Antioxidants, also known as protecting agents, are substances which are added to solutions used in biology, biochemistry or microbiology to prevent chemical changes caused by exposure to oxygen. Cultures of anaerobic bacteria may require the presence of substances buffering the redox potential at negative, reducing values. Breaking cells, especially with ultrasonic waves, introduces oxygen into the cell extract, inducing oxidation of cellular compounds such as lipids or the sulfhydryl groups in proteins. As a result, enzymes possessing functional sulfhydryl groups become inactivated.
Food preservatives are classified into two main groups: antioxidants and antimicrobials.
Antioxidants are compounds that delay or prevent the deterioration of foods by oxidative
mechanisms. Antimicrobial agents inhibit the growth of spoilage and pathogenic
microorganisms in food.
Antioxidants
The oxidation of food products involves the addition of an oxygen atom to or the removal
of a hydrogen atom from the different chemical molecules found in food. Two principal
types of oxidation that contribute to food deterioration
are autoxidation of unsaturated fatty acids (i.e., those containing one or more double
bonds between the carbon atoms of the hydrocarbon chain) and enzyme-catalyzed
oxidation. The autoxidation of unsaturated fatty acids involves a reaction between the carbon-carbon
double bonds and molecular oxygen (O 2 ). The products of autoxidation, called free radicals,
are highly reactive, producing compounds that cause the off-flavors and off-odours characteristic of oxidative rancidity. Antioxidants that react with free radicals (called
free radical scavengers) can slow the rate of autoxidation. These antioxidants include the
naturally occurring tocopherols (vitamin E derivatives) and the synthetic compounds
butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and tertiary butylhydroquinone (TBHQ). Specific enzymes may also carry out the oxidation of many food molecules. The products of these oxidation reactions may lead to quality changes in the food. For example, enzymes
called phenolases catalyze the oxidation of certain molecules (e.g., the amino acid tyrosine)
when fruits and vegetables, such as apples, bananas, and potatoes, are cut or bruised.
The product of these oxidation reactions, collectively known as enzymatic browning, is a
dark pigment called melanin. Antioxidants that inhibit enzyme-catalyzed oxidation include
agents that bind free oxygen (i.e., reducing agents), such as ascorbic acid (vitamin C), and
agents that inactivate the enzymes, such as citric acid and sulphites.
Examples of widely used antioxidants in the EU:
