FNB News - Chemical preservatives in foods – How safe are they?

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F&B SPECIALS

Chemical preservatives in foods – How safe are they?

Monday, 16 September, 2013, 08 : 00 AM [IST]

Venkatesh Ganapathy

Today, the rampant use of chemicals is proving to be of great concern – especially in the cosmetics and food industry. But the truth is that these chemicals are also becoming necessary from a functional perspective.

Food additives or preservatives are substances that are added to food to preserve flavour or enhance its taste and appearance. In its broadest sense, a food additive is any substance added to food. Food acids are added to give a sharp edge to the flavours. They also act as preservatives and antioxidants. Common food acids are vinegar, citric acid, tartaric acid, fumaric acid and lactic acid. Anti-caking agents are used to keep milk powders from caking or sticking. Antioxidants like Vitamin C act as preservatives and can be beneficial to health. The emulsifiers allow water and oils to remain mixed together in an emulsion as in ice creams and homogenised milk.

Almost all of these processed foods contain additives, substances intended to change the food in some way before it is sold to consumers. Additives include flavorings that change a food’s taste, preservatives that extend its shelf life, colourings that change the way it looks, and dietary additives, such as vitamins, minerals, fatty acids and other supplements.

Generally Regarded As Safe
The term GRAS refers to “Generally Regarded As Safe,” the moniker the FDA uses to regulate food additives, dyes, and preservatives. But according to Dr Michael Hansen, a senior scientist at Consumers Union, many additives in our food supply are never even tested. That’s because the GRAS designation is a voluntary process—instead of being required to register food additives, companies can notify the FDA about their product, but only if they so choose.

The food additives that the FDA does regulate are broken down into three categories. "Indirect Food Additives" include packaging materials such as paper, plastic, cardboard and glue that come into contact with food. "Direct Food Additives" include preservatives, nutritional supplements, flavours and texturisers that are added to food. "Colour Additives" are used to alter colour.

Adverse health impacts of food additives
Preserving food by pickling with vinegar, using excess salt to preserve pickles, using sulfur dioxide in wines were some of the age-old techniques. The excess salt usage in pickles is the reason why patients suffering from hypertension (high blood pressure) are advised to refrain from having pickles in their diet. Even food items like papads fall under this category.

Some of the masala powders that are sold along with noodles also supposedly contain chemicals like monosodium glutamate that may be unsafe for children and pregnant women. There was a controversy surrounding ajinomoto used in Chinese dishes. The readymade soup powders are high in salt and chemicals that are needed to increase their shelf life.

The packaged foods are found to be highly processed and they contain a multitude of food additives. Food technologists have always expressed apprehensions that the high level of processing will lead to reduction in the nutrient value of food. In some cases, the additives are required to stabilise the product during the processing itself.

Health problems
Food additives can cause greater health problems in children because they ingest more food per unit of body weight than adults, so exposure is greater in proportion to their size. Researchers are questioning the safe use of artificial additives, especially the mostly unknown effects of how chemicals interact with each other.

Another example is that of lactose intolerance. A significant proportion of the population loses the ability to digest the milk sugar lactose after childhood. Lactose intolerance is especially common among people of Asian or African origin. Those with the condition must limit their intake of milk and dairy foods or this will lead to symptoms like indigestion, abdominal bloating, nausea and diarrhoea. Lactose is used as an additive in the manufacture of biscuits, crisp wafers, medicines, so people with lactose intolerance have to study labels carefully.

As consumers, if you are worried that a particular additive may be causing your symptoms, then it may be worth trying an elimination diet, where you remove the substance completely from your diet and see if the symptoms get better. When you start eating the same additives again and if symptoms continue, then you know where the problem lies.

Adverse reactions
Hydrogenated fats can cause obesity and cardiovascular disease. Artificial food colours can cause allergies, asthma and hyperactivity. Sodium nitrite is added to meats to produce an appealing and fresh red colour to the consumer. Nitrites and nitrates develop into nitrosoamines in the body. These amines are harmful and can affect the physiological systems in our body. Some additives can also cause Attention Deficit Hyperactivity Disorder (ADHD) and exacerbate hyperactive behaviours in children. While artificial additives can cause heart disease, obesity, digestive problems and neurological disorders, natural additives can also cause adverse reactions or allergies.

Blue colorants used to add colours to candy, soft drinks and pastries have produced toxic effects in mice. Testing models on animals like rats, mice, rabbits are poor substitutes for studying similar effects in humans because physiology of such animals and humans can be different.

Many packaged foods that seem healthy often contain fillers, preservatives and other unnecessary ingredients that have very little nutritive value. Look at diet foods – these are lower calorific versions of their high calorie cousins, made by reducing the sugar and / or fat content. Reduced sugar foods and beverages are often loaded with highly processed, chemically derived sugar substitutes.

Fried foods, especially, those that are packaged or come from fast food restaurants, more often than not, contain saturated and trans fats. These fats have been linked to the incidence of cardiovascular disease. Potato wafers that are sold locally are made fresh – however these wafers are fried in an oil (whose quality is suspect) that is heated and re-heated umpteen times. As one nutritionist has remarked, the additives / preservatives in our kitchen need not come from home cooked food alone – they can also originate from the outside food that we eat.

We have little control on the quality of food manufactured in restaurant kitchens. A few years back, there was lot of controversy surrounding the formation of acrylamides in potato wafers, but this seems to have died down. Fast foods are the worst offenders. While you can indulge in pizzas once in a while, making pizzas a regular part of your diet can be a perfect recipe for disaster. Most fast foods are filled with preservatives, artificial flavourings and colourings. People may have forgotten now, but many citric acid-based fruit and soft drinks contained brominated vegetable oil (BVO). BVO increases triglycerides and cholesterol in the blood stream and can damage the liver, testicles, heart and kidneys. High fructose corn can lead to diabetes and stroke.

Potassium Bromate is an additive that is used to increase volume in some white flour, breads and rolls; potassium bromate can cause cancer in animals. Even small amounts in bread can create problems for humans. The other issue is that most food additives are tested in isolation, rather than in combination with other additives. The long-term effects of consuming a combination of different additives are currently unknown.

It is very important for the manufacturers to indicate details on labels carefully and even more important for the consumers to read the labels carefully.

Diet products
Artificial colours and flavourings used in quantities exceeding prescribed limits can lead to problems in health. Many diet products contain artificial sweeteners, which can affect metabolism in human beings. Benzoate preservatives used to preserve fats so that they do not become rancid (oxidised) can lead to asthma, dermatitis and can also affect estrogen balance. Monosodium glutamate (MSG) used in salads, chips, soups can cause headaches, nausea, edema and breathing disorders.

Instant noodles – why are they harmful in the long run
For instant noodles, acid regulators, flavour enhancers, thickeners, humectants, colours, stabilisers, antioxidants, emulsifiers, flour treatment agents, preservatives and anti-caking agents are allowed to use in the making of instant noodles. The use of sodium additives is the main reason why instant noodles are high in sodium. High-sodium foods can cause hypertension, heart disease, stroke, kidney damage and other health problems.

One of the major concerns with instant noodle is that it can produce oxidised fat and oil if it is not managed properly during the manufacturing process. This is of concern if the cooking oil is not maintained at the proper temperature or the oil is not changed as often as necessary.

The prescribed standards also allow the use of 10,000 mg / kg of the chemical propylene glycol, an anti-freeze ingredient as humectants (help to retain moisture to prevent noodles from drying) in instant noodles. Propylene glycol is readily absorbed and it accumulates in the heart, liver and kidneys causing abnormalities and damage. The chemical is also capable of weakening the immune system. Instant noodles and the flavouring soup base also contain high amounts of monosodium glutamate (MSG). It is a flavour enhancer but MSG can trigger an allergic reaction in 1 to 2 per cent of the population. Individuals who are allergic to MSG can get burning sensations, chest and facial flushing or pain and headaches from it.

High sodium consumption is linked to stroke or kidney damage. In Malaysia, there are an estimated 13,000 kidney patients undergoing dialysis. Every year, 2,500 people join the ranks of end-stage renal failure patients. Six new cases of stroke occur every hour in Malaysia.Some food and colour additives have induced allergic reactions, while others have been linked to cancer, asthma, and birth defects. The FDA requires that all ingredients be listed on a food’s label, but additives are often listed without specificity, as "spices" or "flavourings," making it impossible for consumers to determine what, exactly, they are eating.

Further, there are numerous additives that must be listed explicitly on packaging because they can cause health problems. These include sulfites, for example, which are used to prevent discoloration. The FDA estimates that sulfites cause allergic reactions in one per cent of the general population, and five per cent of people who suffer from asthma. Sulfite allergies can develop at any point in a person’s life, and can result in acute, potentially fatal respiratory distress.

Similarly, MSG, which can cause headaches, nausea, weakness, difficulty in breathing, drowsiness, rapid heartbeat, and chest pain, must be identified on food labels because of its potential for harm. However, it is important to know that some ingredients are actually MSG in disguise. The terms “natural flavour” and “hydrolysed yeast extract” are often forms of MSG.

Regulation
Today, food and colour additives are more strictly studied, regulated and monitored than at any other time in history. FDA has the primary legal responsibility for determining the safe use of preservatives.

To market a new food or colour additive (or before using an additive already approved for one use in a manner not yet approved), a manufacturer must first petition the FDA for its approval. These petitions must provide evidence that the substance is safe for the ways in which it will be used.

Sometimes the approvals take years in which case the new product development (NPD) activities of manufacturers get severely hampered. This is one area where the regulation needs to strike a balance.

When evaluating the safety of a substance and whether it should be approved, FDA considers

The composition and properties of the substance
The amount that would typically be consumed
Immediate and long term health effects
Various safety factors.

The evaluation determines an appropriate level of use that includes a built-in safety margin – a factor that allows for uncertainty about the levels of consumption that are expected to be harmless. FDA can never be absolutely certain of the absence of any risk from the use of any substance. Therefore, FDA must determine based on the best science available – if there is a reasonable certainty of no harm to consumers when an additive is used as proposed. Regulations such as GMP (Good Manufacturing Practices) limit the amount of food ingredients used in foods to the amount necessary to achieve the desired effect.

Functional foods are growing at a rapid pace. Government promoted Food Safety and Standards Authority of India (FSSAI) is regulating the claims. Additives are required due to increase in consumption of processed foods. This has eventually led to legislation.

Boric acid was an additive once, but was later banned to be used as a preservative, due to its toxicity. In the late 60s, saccharin, the artificial sweetener was found to cause health problems in rats. In many such areas, research is still emerging and one has to accept the fact that research has an element of subjectivity about it. Banning of an additive based on inferences can sound preposterous, but when it comes to health, one cannot take any chance.

In the European Union (EU), it can take up to 10 years to get a new food additive approved (five years of safety testing and two years of evaluation by FSSAI and three years for approval by the EU). The food standards authorities have to conduct random checks to ensure that the standards laid down by them are followed.

In India, the standards for food products and additives have been prescribed in the Food Safety and Standards (Food Product Standards and Food Additives) Regulations, 2011. These standards are substantially the same as were notified under the Prevention of Food Adulteration Rules, 1955, which got repealed on August 5, 2011. The standards have evolved over a period of time on the basis of contemporary data, scientific development and various other factors impinging on safety of the products and health of the consumer.

For the purpose of this regulation "Good Manufacturing Practices (GMP) for use of food additives" means, the food additives used under the following conditions namely;

The quantity of the additive added to food shall be limited to the lowest possible level necessary to accomplish its desired effect;
The quantity of the additive becomes a component of food as a result of its uses in the manufacturing, processing or packaging of a food and which is not intended to accomplish any physical or other technical effect in the food itself; is reduced to the extent reasonably possible; and
The additive is prepared and handled in the same way as a food ingredient.

R&D testing
Many food additives absorb radiation in the UV and / or visible region of the spectrum. This absorbance can be used to determine the concentration of the additive in the sample using an external calibration. But additives may occur together and the absorbance of one can interfere with the absorbance of another. Therefore, a prior separation stage is needed and additives are separated by HPLC (high pressure liquid chromatography) and then their concentration is determined using UV-visible spectrophotometer.

Summary
Most consumers today rely on the technological, aesthetic and convenient benefits that additives provide. Ingredients are added to foods to maintain or improve safety and freshness, to improve or maintain nutritional value and improve taste, texture and appearance. More than 3,000 additives as well as preservatives are available in the market, which are used as antioxidants and anti-microbial agents. Salt and sugar are the most commonly used preservatives.

Most food additives are listed on the product label, along with other ingredients, in a descending order by weight (flavours are an exception and do not need to be identified). Sometimes, the additive is spelt out in full. At other times, it is represented by a code number.

There are worse things to fear than food additives. Many people view food additives as a major threat. However, in terms of health risk, food additives would come in at the end of the line, after food-borne microorganisms like salmonella, inappropriate hygiene and eating habits, environmental contaminants and naturally occurring toxins.

Manufacturers must trade-off between usage of right quantities of such additives and the benefits arising out of such usage. It is important to have an R&D programme to look into all aspects of toxicity much in advance. In fact, the manufacturers should look one step beyond what the FDA regulation stipulates. They must mention the preservatives and additives clearly on the pack label and must carry out every single task to provide assurance to the customer that what they are buying is safe indeed.

On the one hand, it is important to use additives that have a functionality of preserving the food items for a longer time. On the other hand, these additives also cause side reactions and health effects. Therefore, what is needed is great deal of research in designing new preservative chemicals that are safe to use.

Audits & checks
The ministry of health supported by FDA should conduct periodic audits and surprise checks on food packs containing additives. It is very important to build rigour around this.

Five decades ago, such additives were not necessary as people ate natural foods and had a much less hectic schedule. However, today, the stress levels are high. Lifestyle diseases are on the rise. Disposable income levels are increasing and so is the extent of Western influence. People are relying on processed foods to save time. This is a paradox. On one hand, there is a greater need to have some sort of physical exercise to stay fit. On the other hand, modern lifestyle increasingly depends on processed foods. This is a vicious cycle.

Therefore, the manufacturers have a greater responsibility. A standards rating system can be devised wherein products that are having little risk can be colour-coded differently than other products that have a higher rate of risk element in them. Stricter quality control checks on food imports from other countries is a must. Dumping of goods from other countries must be avoided at all costs.

There is a great deal of misinformation out there thanks to the Internet. So, manufacturers have to take it upon themselves to address the health concerns arising from the use of such additives with consumers. This assurance can result if manufacturers devote time, money and effort in ensuring safety of chemicals used as additives and preservatives.

The FSSAI has given comprehensive list of permitted additives in different ready-to-eat food items. For some additives, the specified limits are mentioned as per GMP limits. For other additives, limits are mentioned. But manufacturers may be exceeding this limit and if this is not detected, additives in excess quantities can lead to adverse metabolic reactions in consumers and adverse health effects in the long run.

For example
Acetic acid or lactic acid used in breads – the limit is 2,500 ppm max while in biscuits the limits are as per GMP limits. For guar gum used in noodles and bread, the limit is 5,000 ppm max. In biscuits, the limit of guar gum is as per GMP. If we look at preservatives / mould inhibitors, the limits are

Calcium or sodium propionate – 5,000 ppm max
Sorbic acid / its salts – 1,000 ppm
Acids like calcium phosphate – 10,000 ppm
Colorants are as per GMP limits
In case of artificial sweeteners, asparatame – 2,200 ppm max, sucralose 750 ppm max

In case of leavening agents like ammonium carbonate, the specified limit is 5,000 ppm max. In case of antioxidants, the butylated hydroxyl anisole has a limit of 200 ppm max while tertiary butyl hydroquinine has a specified limit of 200 ppm max. Emulsifiers have a specified limit of 0.5% max.

Manufacturers should therefore ensure that all ready-to-eat products conform to the specification limits allowed by FSSAI so that gullible consumers do not fall prey to unethical practices. In fact, if you look at a pack of noodles, then ingredients are not mentioned along with the dosages. So, FSSAI has to look into this aspect and also make attempts to increase consumer awareness through continuous education.

Last but not the least, it is _”Caveat Emptor” – (Let the Buyer beware). So, as consumers, we have to be extra vigilant. Preventive health care is any day better than reactive health care.

(The author is Associate Professor, Presidency School of Business, Bangalore and can be contacted at kalakadvganapathy@gmail.com)