One has to just turn the pages of history to find out what our forefathers did to preserve perishable food. Meat and fish were preserved with salt and smoke, fruits were mixed with sugar to last longer and natural ice was used as an effective protective agent for a variety of foodstuffs. Thus adding or using substances to preserve, enhance flavour and or retain nutritive value has been a primitive practice. This practice is still continued, but, with a variety of substances owing to modern science and technological advancement. However, the objective still remains the same. Use of emulsifiers in ice-creams, corn flour in soups, artificial sweeteners in nutrition bars, baking powder in cakes, yeast in bakery products, and a variety of flavours and enhancers is commonly known to man today. All these are nothing but Food Additives .
A food additive is a substance or mixture of substances other than the basic foodstuff which is present in a food as a result of any aspect of production, processing, storage or packaging [Courtesy FDA]. Thus, a food additive may be a substance intentionally incorporated into a product or a substance that becomes a component of food as a consequence of its journey from the field to the family dinner table. Intentional additives are referred to as direct additives that serve some functional purpose in the food such as adding or enhancing flavour, sweetness, or colour, or to prevent spoilage, e.g. sugar, salt. Indirect additives are normally present only in trace amounts resulting from contact of the food with agricultural chemicals, with processing equipment or processing aids, or from contact with the food container.
The Federal Food, Drug and Cosmetic (FFD&C) Act of 1938 gave the FDA (Food and Drug Administration) authority over food ingredients. The 1958 Food Additives Amendment to the FFD&C Act specified the manufacturer s responsibility of prior proof of safety to receive approval of new additives. Additives described as Generally Recognised As Safe (GRAS), mean that they have been used for many years without known adverse effects, e.g. salt, sugar , spices. The GRAS list includes over 600 ingredients that need to be tested by prescribed procedures for every new food item. The GRAS list is regularly reviewed and changed as technology advances.
General Functions of Food Additives
- To maintain or improve nutritive value: Vitamins, minerals and anti-oxidants are added to many common foods such as milk, flour, breakfast cereals, oils, butter and many other processed foods to make up for those likely to be deficient in a person's diet or lost in processing. But it is very important that such products containing added nutrients must be appropriately labeled.
- To control acidity or alkalinity and provide leavening: A leavening agent is a substance used in dough and batters that causes a foaming action. The leavening agent reacts with moisture, heat, acidity to produce gas that becomes trapped as bubbles within the dough. When a dough or batter is baked, it sets and the holes left by the gas bubbles remain, giving cakes, breads and other bakery products their soft, sponge-like textures. Such agents that release acids when heated can react with baking soda to help the above products to rise during baking. Other additives help modify the acidity and alkalinity of foods for proper flavour, taste and color.
- To maintain product consistency: Stabilizers and thickeners thicken the foods, give smooth and uniform texture to the products in which they are added and help them last throughout the production and storage process. Gelling agents in gel foods give shape and structure to a product. Emulsifiers are used to aid in the processing of foods and also to help maintain quality and freshness. In low fat spreads, emulsifiers can help to prevent the growth of moulds which would happen if the oil and fat separated. They give a consistent texture to a product and prevent it from separating. Processed foods often contain ingredients that are mixed as powders. Anti-caking agents are added to allow them to flow and mix evenly during the food production process, e.g. Salt.
- To impart desired colour and flavour: The acceptability of any food product greatly depends on the impression of taste when it is eaten. Many spices, extracts, natural, artificial and smoked flavours enhance the taste of foods. Colours whether natural, nature identical or synthetic enhance the appearance of certain foods to make them look appealing to meet consumer expectations.
- To maintain appearance, palatability and wholesomeness: Preservation tries to alter the conditions to slow or stop the microbial growth. Most preservatives today are fungi static in their action. They prevent the growth of fungi, moulds and yeasts but have little effect on bacteria. Making use of a combination of preservatives with antibacterial properties can give good results. Food preservatives help to control the spread of bacteria which can cause life threatening salmonellosis or botulism. Antioxidants are added to foods, e.g. Vegetable oils, dairy products, mayonnaise to slow the rate of oxidation and extend the shelf life of the food in which they have been used.
List of Commonly used Food Additives, their Functions and Uses.
Vitamins and Minerals
To make up for the processing losses or for fortification.
Thiamin, Riboflavin, Niacin, Iron, Ascorbic Acid, Vitamin A, Vitamin D, Potassium Iodide.
Flours, breads, biscuits, fortified milk, butter, iodised salt, energy drinks, nutrition bars.
Leavening and Neutralising Agents (Buffers)
To increase volume of the product, make it spongy, fluffy and to remove excess acidity/alkalinity.
Tartaric acid, Lactic Acid, Citric Acid, Adipic Acid, Fumaric Acid, Sodium Bicarbonate, Potassium Acid Tartarate.
Cakes, biscuits, muffins, cheese, butter, carbonated beverages, confectionary, baked foods, gelatin desserts.
Emulsifiers, Stabilizers and Thickeners.
Emulsifiers prevent separation of oil and water. When used in combination with thickeners and fats give a smooth, uniform and pleasing sensation in the mouth. Stabilizers ensure a stable emulsion.
Lecithin, Mono and Di Glycerides, Glycol Monostearate, Gum Arabic, Carboxy Methyl Cellulose (CMC), Carrageenan, Pectin, Gelatin.
Bakery Products, cakes, instant pudding mixes, ice creams, frozen desserts, salad dressings, candies, beer, canned milkshakes, jams, jellies, ready to eat sauces.
Colouring Agents (Natural and Artificial)
Preserve, provide or enhance the colour of the food.
Carotene, Cochineal, Annatto, Chlorophyll Nitrates, Caramel Colour, Beet Powder.
Carbonated Beverages, Squashes, jams, jellies, ice creams, baked goods, candies, cheese, fruit flavoured puddings, gelatins.
Flavouring Agents (Natural and Artificial) and Flavour Enhancers
Impart aroma or taste to a food. Flavour enhancers usually supplement or modify the original flavour of a food with a desirable one.
Spices (ginger, clove, cinnamon, pepper, mustard, etc), Herbs, Dry garlic and Onion, Natural lemon and orange flavours and oils, Vanilla, Monosodium glutamate (MSG), Hydrolysed Vegetable Proteins.
Ice cream, carbonated beverages, readymade snacks, chips, squashes, cheese, jams, jellies, barbeque sauce, pie and pudding fillings.
Artificial Sweeteners (Nutritive and Non- nutritive Sweeteners)
Provide less than 2% of the caloric value of sucrose if non-nutritive and more than 2% if nutritive sweetener.
Non-Nutritive: Aspartame, Saccharin, Acesulfame K, Stevioside, Glycyrrhizin.
Nutritive: Sorbitol, Mannitol, Xylitol.
Carbonated Beverages, low calorie foods, nutrition bars, baked goods, milk products, candies, chewing gums, toothpaste, mouth washes, confectionary products, syrups, table top sweeteners.
Retard rancidity and other oxidative damages and thus prevent flavour and colour changes.
Butylated Hydroxy Anisole (BHA) Butylated Hydroxy Toluene (BHT), Propylene Glycol, Propionic Acid, Citric Acid, Ascorbic Acid.
Potato chips, butter, oils, margarine, bread, fruit juices, frozen and dried fruits, cheese, cookies.
Maturing and Bleaching Agents
To impart whiteness and improve appearance.
Chloride Dioxide, Chlorine, Potassium Bromate, Iodate.
Wheat flour, some cheeses and wines.
Anti-caking Agents and Humectants
Prevent lumping and caking by absorbing moisture. Humectants particularly prevent undesirable drying of the product and retain moisture.
Glycerin, Magnesium Carbonate, Sodium Nitrate, Calcium Phosphate.
Table salt, desiccated coconut, sausages, marshmallows, vegetable powders.
Curing and Pickling Agents
Impart unique colour or flavour and increase shelf life.
Meats, sausages, vegetable pickles.
To retain turgor of canned fruits and vegetables.
Calcium carbonate, Sodium Aluminium Sulphate, Calcium Citrate.
Canned tomatoes, peas, pineapples, mushrooms and a variety of fruits and vegetables.
Digestion and Clarification
Pepsin, Rennet, Amylase, Papain, Pectinase.
Meats, Cheese, beer, wines, dairy products.
Sequestering and Chelating Agents
Prevent discolouration, oxidation, flavour alteration, turbidity formation.
Calcium EDTA, Tartaric Acid, Citric Acid, Glycerin.
Carbonated Beverages, malted beverages.
Food Additives and associated Health risks
"All things are poisons; nothing is without poison; only the dose determines whether there is a harmful effect" said Paracelsus (16th Century Philosopher). In simpler words, anything in excess is harmful.
Food additives continue to be a source of benefits to the consuming public but a growing concern and confusion about the safety of food additives and chemicals in our environment has emerged over the last two decades.
Once they are approved by the FDA, food additives are considered to be fit for human consumption. However, it is important to consider that they might not be entirely safe. Some food additives have been known to induce allergic reactions, while others are suspected to cause cancer, asthma, birth defects. The FDA requires that all ingredients be listed on a product s label, but often additives are listed as spices or artificial flavourings thus making it impossible for consumers to gauge the actual content of the product. Historically, food additives such as preservatives, flavour enhancers, colouring agents, nitrites have been linked to adverse reactions. Major concern on the part of the public in recent years has been focused on man-made chemicals which are intentionally added to foods to enhance their flavours, acceptability, nutrient value, shelf life and availability.
Research suggests that asthamatics are the most likely to react to food additives especially to tartazine, azodyes, benzoic acid, BHA and BTA. The most important skin symptoms involving immunological reactions caused by these food additives are urticaria (A skin condition characterized by welts that itch intensely, caused by an allergic reaction, an infection, or a nervous condition. Also called hives or nettle rash) and angioneurotic edema (Recurring episodes of non-inflammatory swelling of the skin, mucous membranes, viscera, and brain, occasionally accompanied by arthralgia, purpura, or fever). Non-immunological contact urticaria is produced by numerous spices, benzoic acid, sorbic acid, cinnamic acid and many essential oils. Asthma and rhinitis (an inflammation of the mucous membrane lining the nose, usually associated with nasal discharge) are the main hypersensitivity symptoms in the respiratory tract and azo dyes, benzoic acid, and sulfitic food additives are the most common causative agents. FDA has banned the use of sulfites on raw fruits and vegetables and on commercially marketed fresh potatoes while continuing to monitor sulfite use on other foods. Certain psychological factors also play an essential role in both food and food additive reactions.
Adverse reactions to Monosodium glutamate (MSG) or ajinomoto (as popularly known in
) are reported to include headache, nausea, flushing, abdominal pain, asthma and even cancer. Whether or not MSG actually causes this response is still controversial. But one should have a constant check on his/her MSG intake. Chinese food and highly processed snacks which are laden with MSG must be eaten in limited amounts. India
There have been numerous researches on association between the use of food additives, dyes, sweeteners and the occurrence of behavioural symptoms such as hyperactivity but these relationships have failed to be supported by controlled studies. Improved behaviour has been reported in preschool boys with Attention Deficit Hyperactivity Disorder (ADHD) who consume an additive free and caffeine free diet that is low in sugar. However, these effects may be a result of decreased caloric intake altogether. Elimination diets may always not be possible for the routine management of such kids.
Regulation of Food Additives
The Food, Drug and Cosmetic Act of 1938 plus amendments in 1958 and 1960 give regulatory powers to the FDA. One part of those amendments i.e. the Delaney Clause which prohibits the use of any food additive (including colours) if it has been shown to induce cancer at any level in animals or man. The FDA regulates the type of food an additive can be used in, the maximum quantity that can be used and the information that must appear on the label. Additives are never given permanent approval, but are continually reviewed, and modified or withdrawn as and when it feels necessary.
A maximum level of an additive that has no demonstrable toxic effect is called the 'no-observed-adverse-effect level' (NOAEL) and is used to determine the 'Acceptable Daily Intake' (ADI) figure for each food additive. The ADI provides a large margin of safety and refers to the amount of a food additive that can be taken daily in the diet, over a lifetime, without any health problem. Regulations known as Good Manufacturing Practices (GMP) limit the amount of food and colour additives used in foods. Manufacturers use only the amount of an additive necessary to achieve the desired effect.
The PFA (Prevention of Food Adulteration Act) gives the definition and list of permissible additives along with their amounts permitted. The substances that are used as food additives should be of food grade and must meet the PFA or BIS (Bureau of Indian Standards) specifications. The use of additives is prohibited by law in infant foods when used to cover defects or spoilage or when used to make food attractive at the expense of its safety.
Additives have been used for many years to preserve, flavour, blend, thicken and colour foods and have played an important role in reducing serious nutritional deficiencies thus making their use imperative. They also provide protection against food spoilage during storage, transportation, distribution or processing and assure a product s wholesomeness, palatability and affordability to meet consumer demands from season to season. The convenience food revolution would not have been possible without food additives. Presently, food and colour additives are more strictly regulated than at any time in history but an important thing to consider is that their use simultaneously has increased dramatically in a variety of food products all over the world. Federal regulations and laws require evidence that each substance is safe at its intended levels of use before it may be added to any foods. All additives are subject to ongoing safety review as scientific understanding and methods of testing improve day by day. However, people who have special diets or intolerances should be careful in selecting products and read the food label before consuming any product.