FOOD ADITIVES

Food additives are intentionally added substances to food. These are normally added in small quantities and are not consumed as foods by themselves. These serve as aids in the preparation and processing of food, to improve quality, appearance, taste, odour, texture, consistency, acidity or alkalinity etc.

Food additives aid the manufacturers but the benefits to the consumer are often debated.

Food additives may be classified as follows:-

1. Preservatives

2. Anti-oxidents

3. Permitted colours

4. Sweetening agents

5. Emulsifiers and Stabilizers

6. Anti-caking agents

7. Firming agents – humectants

8. Acids, Buffers and Bases

These do not include vitamins, herbs and spices and contaminants arising from agricultural practice etc.

Food laws stipulate that labels must list all ingredients in descending order of proportion by weight. Thus food additives appear almost at the end of the list as a code number. These numbers are based on an internationally accepted system replacing long chemical names. The prefix letter E appearing before the number indicate that it has been approved by the European Community e.g. E220 refers to Sulphur dioxide.

Adverse reactions to food additives occur only in a small proportion of the population. Such people could avoid these on recognising the presence of the particular additive from the label.

Preservatives

Preservatives means a substance which when added to food is capable of inhibiting, retarding or arresting the process of fermentation, acidification or other decomposition of food. These acts as antimicrobial agents and inactivate or inhibit the growth of moulds and bacteria in foods.

The preservative regulations permit the presence of only specified preservative within prescribed limits in some foods.

Sulphur dioxide in the form of gas, in solution as sulphurous acid or as sodium, potassium and calcium sulphite is commonly used as a preservative in fruit juices, jams, cider, bear etc. while benzoic acid derivatives are also used in fruit juices, diabetic jams, bear etc. weight by weight benzoic acid is only half as effective as sulphur dioxide.

Sodium nitrate and sodium nitrite are permitted within maximum limits in cured meat, salami, bacon and ham and some cheese. Added nitrates and nitrites are prohibited in all infant foods. These have the potentiality of forming the carcinogenic nitrosoamines, which are harmful to all including infants.

Propionic acid is a permitted preservative in flour confectionary Christmas pudding and in bread within maximum limits. However, it is banned in Germany. Sorbic acid is also permitted in flour confectionary, cheese, cider, yoghurt, curd and some ready to drink beverages.

Biphenyls, 2-hydroxy biphenyls and 2-thiaxol-4-benzimidazole are permitted in citrus fruits.

The abusive and unlawful use of formalin as a preservative in fish and malathion in cereals and pulses have occurred in some developing countries. Malathion is freely available in tropical countries as it is now widely used for spraying against malarial vectors.

Table 1 presents a summary of the permitted preservatives in specified foods and maximum allowed levels in mg/kg.

Specified food	Permitted Preservative	Maximum allowed level mg/kg
1. Beer	SO2, Benzoic acid or other derivatives of Benzoic acid	70
2. Bread	Propionic acid	3000
3. Cheese	Sorbic acid	1000
4. Cider Wines	SO2 or Sorbic acid "	200 350
5. Desiccated Coconut	SO2	50
6. Flour Confectionery	Propionic or Sorbic acid	1000
7. fresh fruits a) Citrus b) Grapes	Biphenyl 2-Hydroxy Biphenyl 2-Thiaxol-4-yl benzimidazole SO2	70 12 20 15
8. Fruit Juices	SO2 Benzoic acid or derivatives	350 800
9. Jams	Residual SO2	100
10. Diabetic Jams	SO2	100
11. Sausages	SO2	450
12. Meat cured	NaNO3 NaNO2	500 200
13. Ready to drink beverages	SO2 Benzoic acid or derivatives Sorbic acid	70 160 200
14. Yoghurt	Sorbic acid SO2 Benzoic acid or derivatives	300 60 120
15. Curd	Sorbic acid	300

Antioxidants

Antioxidants are substances capable of delaying, retarding or preventing the development in food of rancidity or other flavour deteriorations and spoilage due to oxidation and prolonging shelf-life.

Ethyl, propyl, octyl and dodecyl gallates are commonly used antioxidants with a maximum permitted level of 100 mg/kg in edible oils and fats, ghee and margarine while the amount for butter fat used for manufacturing purposes is reduced to 80 mg/kg.

Butylated hydroxy anisole (BHA) or butylated hydroxy toluene (BHT) or a mixture of both are allowed in edible oils, fats, margarine and ghee to a limit of 200 mg/kg while the limit for butterfat used for manufacturing purposes is 160 mg/kg. Gallates, BHA and BHT are prohibited in baby foods. These included 1-ascorbic acid and tocopherols which also serve as antioxidants.

Colouring matters

Colours are as turmeric and saffron have been used in food from ancient times to please consumers. However, regulations had to be brought in to prevent the diaguise of inferior products, the use of metallic coloured salts and non-permitted coal-tar dyes in foods. Poisonous copper sulphate had been used to colour pickles, alum to whiten bread, plant extracts to colour beer and molasses, dyes to spent tea leaves, yellow colour to mask adulterated milk etc.

Only permitted colours which satisfy purity criteria are now allowed in specified foods. Regulations exist for these purposes. Also when colour is added to any food the label must state “Artificially Coloured”.

Among the red permitted colours are carmoisine, fast red E, ponceau 4R, and erythrosine BS. The blue colours are indigo-carmine, brilliant blue FCF while the green colours are S and green FCF. The yellow colours are tartrazine, amaranth and sunset yellow. Amaranth has been banned in the USA.

Raw or unprocessed meat, poultry, fish, fruits and vegetables, tea, coffee beans, ground coffee, coffee extract, bread, cream, condensed milk, dried milk, cheese and butter are not permitted to have added colours. Butter may however contain annatto and carotene. Colours are also prohibited in baby foods.

Sweetening agents

Sugars are high energy foods and these have been replaced by very low energy and non nutritional artificial sweeteners such as saccharine, cyclamates and aspartame. Saccharine and cyclamates have been accepted for carbonated drinks, gelatine deserts, pudding mixtures, jams, jellies, diet jams, cordials, custard and soft drinks. These artificial sweeteners are not permitted in baby foods.

Cyclamates still remain banned in the USA although some attempts have been made to remove this band.

Acesulfame – K is an approved sweetener in more than 20 countries

Genetic engineering has yielded some promising peptide sweeteners.

Other less sweetening agents that yield bulk in sugar free products used for special diets and by diabetics are sorbitol, mannitol and polyhydric alcohols. Thaumatin, which is 3000 times sweeter than sucrose is also a permitted sweetener in some countries. It is found in the fruit of a West African plant called Katemfe.

Non- nutritive sweeteners in food regulations limit the amount allowed in foods.

Analytical methods which include TLC, spectrophotometry and HPLC are available for the detection and estimation of artificial sweeteners.

Emulsifiers and Stabilizers

Any substance which is capable of aiding the formation of a stable mixture of two otherwise immiscible substances such as oils, fats and water is called and emulsifier and any substance that helps to maintain an emulsion which has been formed is called a stabilizer.

Edible gums and agar were used in the early days but they have been replaced now by lecithin, polyphosphates, cellulose esters, poly and partial glycerol esters, propylene glycol esters, carboxy methyl cellulose, stearyl tartrate and monostearin sodium sulphoacetate etc. These are used in bread, flour confectionery, ice-cream, margarine, chocolate, sugar confectionary, processed meats, sauces, dessert mixtures.

Wood resin or ester gum used in beverages and chewing gum and derived from the stumps of longleaf pine are a complex mixture of tri and diglycerol esters of resin acids.

Food regulations specify permitted emulsifiers and stabilizers with limits in foods and also prescribe purity criteria fro emulsifiers and stabilizers.

TLC, HPLC and GLC methods including colorimetric methods are available for the detection and estimation of emulsifiers and stabilizers.

Anti-caking agents: these are substances that ensure a free flow when poured from containers e.g. salt. Magnesium carbonate amounting to 0.3-1% is added to salt to health the free running properties. Phosphates, silicates and fatty acid salts are also used in other foods but the maximum total amount allowed is 20g/kg.

Firming agents and humectants: these enhance the texture and uniform consistency of the food. Humectants prevent foods from drying out. Glycerine, lacitol, mannitol and propylene glycol are common humectants.

Thickeners used in present day foods are modified starches, carrageenan etc. carrageenan is a plant gum derived from a variety of sea weed. It was also called Irish moss and named after a town carragheen in Ireland.

Acids, buffers and bases: these are added to maintain a constant pH level in foods.

Flavour enhancers and flavourings are used for improving the existing flavour or aroma of the food and to retain losses during processing and to make the food more palatable.

Glutamates, ribonucleotides and protein hydrolysates are used as flavour enhancers in soup mixes, sauces and meat products. Ribonucleotides include disodium inosinate and disodium guanylate.

Monosodium glutamate (MSG) is a common flavour enhancer used in Chinese restaurants. MSG is the sodium salt of glutamic acid, one of the most common amino acid found in foods. One fifth of the body’s protein is a glutamate. MSG, besides being a flavour enhancer has also a basic taste named “umane”. Excessive amounts of MSG cause the Chinese restaurant syndrome or Kwok’s Quease which includes headaches, dizziness, muscle tightening, nausea, weakness of upper arm, pains in the neck etc. MSG is prohibited in baby foods. Allergies to MSG exists, as in many other foods.

Apart from food additives already included above, there are others such as enzymes which act as catalysts. These may also act as tenderizers, flavour enhancers, stabilizers, antioxidants and preservatives.

Foods with added flavours, natural of synthetic should be labelled accordingly.

The list of food additives are increasing every year and adequate safeguards are needed. There is a joint FAO/WHO expert committee on Food additives to monitor new additives and to recommend or not their use including establishments of safety limits. The safety limits are included in the food standards established by Codex Alimentarius Commission of the FAO.

Consumers demand more additive free foods, but the food industry rely heavily on additives. Food additives, while serving the purpose for which they are added, should be safe and beneficial to the consumer.

Global Warming

Global warming is a concept that denotes the temperature increase in the earth’s atmosphere due to the huge emissions of carbon dioxide emitted by human activity, mostly through the inconsiderate combustion of fossil fuels, such as oil and coal. Although climate scientists have been warning against the potentially disastrous effects of global warming for decades, no large-scale counter-measures have been taken so far. Scientists say that global warming will cause increasingly extreme weather patterns: greater heat, greater cold, stronger wind, more or les rain. The increasing warmer temperatures are causing the ice caps in the North and South Poles to melt, which results in rising sea levels. A recent research project that analyzed trapped air in the Antarctic ice core concluded that the present levels of CO₂ are the highest in 800,000 years, that the fastest increase during that period was during the last seventeen years, and that a similar hike in CO₂ levels has never happened in less than a thousand year period up to now. One of the researchers involved said that there is nothing in the ice core that gives us any reason for comfort and that changes of CO₂ levels in the past have always been accompanied by climate change. Although skeptics, especially in the USA, doubt that human activity is responsible for global warming, suggesting that it could be natural occurrence, leading climate scientists and politicians such as AL Gore and Tony Blair connect global warming to the ever increasing combustion of fossil fuels.

Global warming is a global problem in the sense that it is caused globally and has effects globally. The emission of CO₂ in one area of the world will have effects on the climate everywhere. Thus, even if the emission of CO₂ is reduced in Europe, the great increase of CO₂ emissions in rapidly developing countries such as India or China will cause this reduction to have no effect.

The Prime Minister of Britain, Tony Blair, said that the world was facing “nothing more serious, more urgent, or more demanding of leadership” than climate change. Speaking at the launching of a major economic report commissioned by British Treasury, Blair said there was “overwhelming scientific evidence” that climate change was taking place and that the consequences of failing to act would be “disastrous”. According to the report, “Our actions over the coming decades could create risks of major disruption to economic and social activity, later in this century and in the next, on a scale similar to those associated with the great wars and the economic depression of the first half of the 20^th century.”

A recent UN report, the Global Biodiversity outlook, states the need for unprecedented effort to slow down the decline in the richness of natural systems throughout the world. More species of animals and plants are becoming extinct now than at any time since the demise of the dinosaurs sixty five million years ago. And this is all due to human activity. The misuse of modern technology causes our natural environment to collapse in such a way that eventually it might not be able to support people anymore.

Recently, I had first hand experience of the effects of global warming when visiting Europe. When I grew up in the Netherlands, it was a cool and drizzly country even in summer. However, when I was there at the end of June, a tropical heat wave started to envelope the whole of Northern Europe, and in some areas temperatures soared above 35?c.These extreme heat waves were unknown in Northern Europe until few years ago. When the heat wave was over, unprecedented tropical rainstorms inundated streets .At the time of writing this article, at the end of October, 2006, the temperatures are still unusually high in the Netherlands. The trees still carry their leaves, which would normally only be found in distant southern European areas with mild winters and warm summers, have started to appear in the Netherlands during the last few years. Due to the warmer weather, southern creatures find conditions suitable in the north and rapidly move up. Another consequence of the heat waves in Europe was that yields of crops were affected, and consequently the prices of certain foods such a milk and bread went up. With a large part of the Netherlands being land below sea level that is only protected by dykes from the sea, Dutch government organizations are naturally taking global warming seriously. Serious plans have been made on how to deal with drastically rising sea levels, and what to do when the large rives that flow through the Netherlands overflow due to rapidly melting snow in the Alps in spring and heavy rains in summer. In Switzerland, where I also went, I was told that the glaciers on the mountains are disappearing, and where there previously was ice and snow on the mountains during the summer, now there is none.

Recent plans for shifting over from fossil fuels to nuclear power would increase the risk of nuclear disasters, and besides this, the building, maintaining, and especially the decommissioning of nuclear plants and the storage of nuclear waste uses tremendous amounts of energy obtained from fossil fuels. The is no guarantee that future societies, which might not have the same resources as we have now, will be able to handle nuclear waste left over from us. Moreover, uranium is an even more limited resource than oil, and economically viable extraction might finish within twenty years. Alternative energy sources, such as wind and solar power, are attractive alternatives, but, as these technologies don’t create large-scale industries and income for governments, their introduction has been slow.

Among the family and friends I talked to in the Netherlands there was a general acknowledgment that the climate is changing: however, when one touches upon the causes and results of it, then a visible uneasiness arises, and the topic is changed. For many, it is difficult to accept that human activity can change the climate. Weather has always been something that has been considered unpredictable and uncontrollable. In pre-modern times, and still, in traditional cultures, it was supposed that gods who controlled the weather, and the only thing that humans could do was to try to placate such gods by making offerings. With the rise of the scientific technological worldview, the consequent belief in an all-controlling god responsible for the weather vanished. Statistical research in Netherlands has shown that when fertilizers and pesticides first started to be used on large scale in the 1950s, church attendance in farming communities drastically dropped because farmers no longer needed to solicit the help of God for a successful harvest, Even then, although the weather could be predicted to a fairly accurate degree, it was not believed that humans could influence or control the weather. Now, however, it has become apparent that humans are responsible for the increasingly extreme weather patterns that are appearing in many parts of the world. A reasonable argument for this possibility is that, if people are responsible for such drastic changes in the natural world as the holes in the ozone layer in the stratosphere, the drying up of the Aral Sea in the former then why couldn’t people cause atmosphere to heat up?

Most people don’t want to think about the prospect of having to live in a world with increasingly extreme weather conditions combined with increasingly limited natural resources to compensate for the calamities such as floods, famines, mass refugee movements, and warscaused by it.

In the case of global warming, although the effects seem at first unclear and slow, scientists are warnings us, once it has started, there will be no way it can be stopped. The carbon dioxide and methane now put in to the atmosphere will not leave it for decades. The comfortable view that technology is eventually going to solve all problems can be considered a wrong view. It is wrong in the sense that is the nature of the world to be uncontrollable. New problems will always crop up. Due to a wrong, unrestrained use of technology, modern humanity could end up off worse-off than is les technologically advanced, but perhaps more sensible and content ancestors.