Frequently Asked Questions

Food technologists take great care to ensure that food products are safe and wholesome. But eating or drinking too much of any food can be bad for you - too much water can kill you. We shouldn't think of good foods or bad foods, but of good or bad diets. However, concern with the growing problem of obesity has led the UK Government (and others) to seek labelling and other methods of advising consumers on "healthier" foods and "less healthy" foods.

A good diet is a balanced one - a selection of different foods and not too much of any one food. That way you get all the nutrients that you need. Many countries have guidelines for healthy diets, including in some cases recommended daily amounts of specific nutrients. However, diet should not be considered in isolation, but in conjunction with exercise and a healthy lifestyle. It is emphasised that these dietary guidelines are for healthy individuals, not for those with disease symptoms or food allergies or intolerances. These people should consult their doctor or a dietician.

You should automatically get enough protein to stay healthy if you eat a varied diet in sufficient amounts to stop you feeling hungry.

Not in itself but if you eat a lot of sugar in the form of sweets (candy) you may not eat enough of those foods that you need to provide your body with the nourishment it needs. Sugar can cause dental decay if you eat sweets or drink sugar-sweetened drinks too often and too frequently. You need to clean your teeth afterwards, otherwise the sugar sticks to your teeth causing dental plaque and subsequent tooth decay.

Honey is largely a strong solution of sugars called fructose and glucose, which affect teeth only very slightly less than ordinary sugar (sucrose). There is nothing especially healthy about honey. The traces of micronutrients it contains are too small to make any significant contribution to our diet.

Sugar is used in some foods to make them sweet. In others it is used in small quantities not to sweeten but to enhance the flavour. In some foods, however, sugar is an essential part of recipe and/or provides texture or structure and/ contributes to preservation, e.g. jams or preserves and cakes and biscuits (cookies).

Salt is essential to a healthy diet. We need about 1 g of salt a day. However, many of us consume about 10 g a day, ten times as much as we really need. A single dose of ten times that amount could be fatal! There is evidence that, for some people, too much salt can be a contributory factor to high blood pressure. Just how much is 'too much' varies from person to person. The UK Food Standards Agency recommends less than 6g per day.

There is enough salt naturally present in food to satisfy our daily 1g need. However, salt is sometimes added during processing or cooking of food to enhance and improve the taste and flavour. Also we, consumers, often sprinkle salt on our food for the same reason. Salt is also used to preserve some foods. Salt curing is one of the earliest known forms of food preservation.

As with all foods, but more importantly with fats, too much is harmful. Many common diseases such as heart disease are linked to high consumption of fats, more especially saturated fats - the type mostly found in animal fat.

Fats in foods, or, more correctly, their fatty acids, are of three main types, saturated, monounsaturated and polyunsaturated.
Saturated fatty acids carry a full quota of hydrogen atoms in their chemical structure. This is the type that increases the amount of cholesterol in the blood and is considered a risk factor in heart disease; animal fats are the main source.

When one pair of hydrogen atoms is missing, the fatty acids are called monounsaturated. They do not raise blood cholesterol and may even be beneficial. The main sources are olive oil and rapeseed oil (used in some margarines and low fat spreads).

When more than one pair of hydrogen atoms is missing, the fatty acids are called polyunsaturated. They predominate in most vegetable oils. Most appear to have no effect on blood cholesterol levels but are useful if they replace saturated fats in the diet. However, those found in fatty fish and fish oils (called omega-3 polyunsaturated) are considered to help to lower cholesterol and so may be beneficial.

No, because some are essential, and we need a certain amount of fat in the diet to be able to absorb fat-soluble vitamins. Compared with an average Western diet, a prudent diet would contain a reduced intake of total fat, and, within that, a lower proportion of saturated fat and a higher proportion of mono- and polyunsaturated fats.

Vegetable oils are liquid at room temperature. To make them suitable for use in margarines and shortenings, they are hydrogenated, i.e. treated with hydrogen, to solidify them. The process adds hydrogen atoms to their chemical structure and makes them more saturated.

Trans fatty acids are a type of mono-unsaturated fatty acid. They may be produced when oils are hydrogenated in the manufacture of margarine and some occur naturally in milk and butter. While some research suggests that trans fatty acids may be harmful, other evidence is conflicting. As yet there is no official recommendation on the subject, other than that the amount currently consumed should not be increased. However, current FSA advice is to reduce the total amount of fat we eat as well as the amount of foods that contain hydrogenated or saturated fats and replace them with unsaturated fats.

There is no simple answer. Butter contains more saturated fatty acids than margarine, but less trans fatty acids than some margarines.

Nearly everything we eat comes originally from a natural source, but much of it is processed to preserve it so that it keeps better (e.g. canned, frozen or chilled foods); or to make it easier to eat (like bread); or to make it safer (like pasteurised milk).

In some instances processed food is better for us, for example because harmful substances naturally present have been removed or destroyed during processing, or because the food has been enriched with nutrients. In other instances there is no difference. It could be argued that, taken in isolation, an apple for dessert is better for you than a chunk of Black Forest Gateau covered in cream; but even in the healthiest diet, there is room for an occasional indulgence.

To make them palatable, edible, convenient and to have suitable keeping properties. Processing also adds variety to the diet by making new foods from combinations of ingredients - just as cooks have done down the ages.

Not necessarily. Current nutritional advice, to eat less fat, more fibre, more fresh fruit and vegetables and more starchy foods, may be easier to achieve with a vegetarian diet. However, animal foods provide a concentrated source of protein, vitamins and minerals. These nutrients can be obtained from a vegetarian diet, but, there can be difficulties with protein quality and with some micro-nutrients, especially with vitamin B12, calcium, and vitamin B2 (riboflavin) if milk products are left out of the diet. In a typical western diet, some 40% of the vitamin B2 intake derives from milk products. Someone new to a vegan or vegetarian diet that excludes milk products will not necessarily be aware of the nutritional consequences, nor of the need to take supplements to help avoid deficiencies. Nowadays, there are numerous yeast-based spreads and supplements containing B vitamins including vitamin B12 for their use, some also with added vitamin B2.

The Vegetarian Society provides a wealth of vegetarian nutrition information to help ensure the nutritional adequacy of such diets.

Eating more fruit and vegetables and less fat does at first sight cost more, and needs more careful selection of foods. On the other hand, if these foods are replacing prepared convenience foods and fatty-sugary foods, there may actually be a cost-saving.

A balanced and varied diet - not too much of anything - should normally supply enough vitamins and minerals. There may be problems for children, adolescents, the elderly, women during pregnancy and lactation, and for people on slimming diets. These groups may benefit from additional vitamins and minerals either from the food they eat or a supplement. There is also increasing evidence that certain vitamins (i.e. vitamins C and E) have additional beneficial properties as antioxidants.

Some people who favour organic foods claim that they taste better. However, there is so much flavour variation among different varieties, different degrees of ripeness or freshness, or length of storage of the same fruit or vegetable, that it is very difficult for individuals to make true comparisons. Generally, when attempts have been made to carry out scientifically-designed blind-tasting tests on the same variety, organic versus non-organic, taste panels have been unable to detect a flavour difference.

No individual foods will positively help disorders of this kind, although there is some evidence that a diet low in saturated fats and high in polyunsaturated fatty acids (particularly the omega-3 polyunsaturated fatty acids) could benefit sufferers. Although there are various anecdotal claims about benefit from avoiding certain foods, there is little or no scientific evidence to support them.

No convincing scientific evidence has so far been forthcoming to substantiate claims for any of these supplements.

This commonly-used term is used by some people to describe foods of which they disapprove. It has, for example, been applied indiscriminately to all fast food and all snack foods. It has also been applied to any food high in fat and/or sugar (and so in calories) but low in other nutrients. However, there is no evidence that such foods are other than acceptable as part of a balanced diet.

More food and nutrition information sources can be found on numerous websites including:

• UK Food Standards Agency
• US FDA Center for Food Safety and Nutrition
• International Food Information Council
• USDA Food and Nutrition Information Center (FNIC)
• FNIC databases
• FNIC NAL Resource list
• British Nutrition Foundation

Food poisoning is illness caused by harmful amounts of natural or contaminating substances in a food. Symptoms include abdominal pain, diarrhoea and vomiting, and may last from a few hours to a few days. In extreme cases food poisoning can prove fatal, especially to babies, the elderly and others with weakened immune systems. Food poisoning can be caused by the growth of highly infective kinds of bacteria in the food. If not prevented by care and good hygiene the bacteria multiply and grow producing toxins (poisons), some of which are difficult to destroy by cooking. Other kinds of bacteria can cause illness by growing to large numbers in the digestive system.

Food scientists and technologists working in the food industry take great care to try to ensure that food products are safe and wholesome. It is probable that increased food poisoning statistics are due to a number of factors including:

• increased public awareness resulting in large numbers of previously unreported 'stomach upsets' now being reported as cases of food poisoning;
• changing lifestyles and shopping habits, for example shopping less frequently in larger amounts means storing food for longer periods;
• mishandling, storage or preparation of foods because of a lack of understanding of the best way to keep and cook foods. This is particularly important with the increased availability of chilled foods which need more carefully controlled low temperature storage than is sometimes provided in the home.
• the emergence of some hitherto unknown or new strains of micro-organisms.

It is a fact of life that dangerous microbes threaten the safety of food from farm to table. Food safety calls for many measures and for great care to be taken at every stage of the food chain. Therefore, the overriding requirements for the manufacture of safe and wholesome foods in every food operation are knowledge of food law and how to set up effective food safety and quality control systems, as well as knowledge and practice of food hygiene by everyone who handles or takes decisions about handling, food, whether in factories, distribution, retail, catering (foodservice) or in the home. Food hygiene training is important, not only for food businesses therefore, but also for consumers and children who, as tomorrow's adults, should be taught food hygiene so that it becomes second nature to them.

This fear is groundless and the opposite view, that all food should be completely sterile, is totally unrealistic. Bacteria are around us all the time and food can only be made sterile, by putting it into a hermetically-sealed container (e.g. a can) and treating it with a defined heat process to sterilise it. Even then, once the can is opened, the food is exposed to the air and to contamination by airborne microorganisms. But even when the food is consumed, it is not the presence of microorganisms that is of concern. Danger only comes if bacteria are allowed to multiply to large numbers in food or in the digestive system. This is preventable by taking great care and ensuring good hygiene at all stages of raw material handling, manufacture, distribution, retailing, catering and in the home.

Irradiation is one of many comparatively new methods of safe food preservation, but it is the only method (apart from ultra-high pressure) of pasteurising without the use of heat. As such it is particularly valuable at appropriate levels for certain limited applications, such as soft fruits and prawns, where quality is retained better than in heat pasteurisation. It is a controversial technique but, despite media scare stories, tests show that it is a safe and reliable process. Its use for any particular food in any country depends on governmental approval, economics and public acceptance, but just as we have come to accept pasteurisation of milk and the use of microwaves, where the quality and safety of irradiated products proves superior to un-irradiated foods and the economics are viable, then concerns may in time disappear.

There is nothing new about genetic modification. Traditional breeding methods to improve animals and plants are genetic modification by a slow, hit-and-miss means. Science now enables it to be done systematically and more rapidly. What is different, and could not be done by traditional breeding, is the purposeful copying of genes from one species to another.

The newer kinds of genetic modification can provide immense benefits in human well-being world-wide, especially in medicine, agriculture and food. As with every bit of mankind's progress from being a cave dweller, it is a form of interference with nature. Any new technology has potential hazards but if we had been scared to pursue all new technologies we would still be living in the Stone Age. The answer is to foresee hazards and eliminate them (for example, to avoid the risk of loss of genetic diversity). That is why the introduction of any new genetically-modified food is controlled in the EU under Directive 2001/18/EC and Regulation 1829/2003, with the stringent assessment and recommendations of the European Food Safety Authority.

The officially appointed UK Committee on the Ethics of Genetic Modification and Food Use, chaired by the Rev. John Polkinghorne, which reported in September 1993 on all the moral and ethical issues involved, found that these concerns were misconceptions rather than of real substance, arising from lack of knowledge outside the scientific community of just what was involved.

The fact is that any gene extracted from one species for copying into another, is not itself inserted but is copied - in the laboratory - and then diluted millions of times before a single gene is transferred. The chances of the original gene being found are much less than the chance of recovering a particular drop of water from all the oceans of the world. If this were widely understood fears of cannibalism or of contravening religious food taboos would be seen to be unwarranted.

EU legislation has been passed which requires food containing ingredients produced from genetically modified organisms, to be indicated on the label. These new rules came into force in April 2004 and require that any intentional use of genetically modified ingredients are labelled. Products produced through GM technology (cheese produced with GM enzymes, for example) will not have to be labelled.

Products such as meat, milk and eggs from animals fed on GM animal feed will also not need to be labelled. However, products containing small amounts of GM ingredients (below 0.9% for approved GM varieties and 0.5% for unapproved GM varieties that have received a favourable assessment from an EC scientific committee) and are accidentally present in a food do not need to be labelled.

Based on present scientific evidence, and provided that all approved control measures are in place, the consumption of muscle meat, milk and tallow from British cows, would appear to involve virtually no risk of causing vCJD, i.e. to be safe within the normal meaning of the term. Government experts have stated that, if there is any risk to humans, it is extremely small, and no greater for children, hospital patients, pregnant women or people who are immuno-compromised than for healthy adults.

As regards animal health, measures have been taken, and strengthened, to reduce the incidence of BSE in cows and these have led to a dramatic reduction in new cases and are expected to lead to the virtual elimination of the disease. On the basis of present scientific knowledge, no further animal-related measures are needed.

While that sums up the present state of knowledge, scientists always have to keep open minds. They have to act on existing knowledge while recognising that further research will bring new information and knowledge, which may in turn lead to revised conclusions.

Many foods depend on additives for safety, stability or preservation. Preservatives inhibit growth of microbes that cause food poisoning. Ham and bacon would be highly dangerous without the preservative that also gives them their characteristic colour. Freedom from separation, or a smooth creamy texture, depends on emulsifiers. Without other kinds of additives many foods would look less pleasant, or taste less pleasant, or go off more quickly, or cost more.

In European countries all additives are controlled by law, and only those that have undergone stringent tests for need and safety in use, and which been approved by independent committees of scientists and medical experts are permitted, up to the maximum quantities specified. A similar situation applies in most other countries. Some people are allergic to, or intolerant of, particular additives; many more are allergic to, or intolerant of, substances naturally present in foods, such as strawberries, fish, nuts, etc.

Part of the enjoyment and appeal of food is its appearance, including its colour. Cooks and chefs have always used colours in cooking to enhance appearance or to compensate for colour deterioration during cooking. The same applies to some manufactured foods. For example, without colour, margarines appear grey and unpalatable; with colour they are visually attractive and popular. The colours used are only those that have been tested and found satisfactory by the same stringent procedures as those for additives in general. Colour judiciously used adds to the enjoyment of food.

Sixty years ago our food was grown, farmed and processed within relatively short distances of retail outlets. Today, foods originate all over the world. The functions of packaging have multiplied and foods must be protected and kept in good condition during transport and storage throughout the distribution chain. All the skill, quality, and reliability built into the food during growing, processing, and preparation will be wasted unless proper design and manufacture of packaging ensures 'safe delivery to the consumer in prime condition at an economic cost'.

The role of packaging in the food industry has expanded rapidly in recent times. Technical and commercial innovations have transformed what was the simple use of wrappings and containers to the keystone of logistics efficiency. Packaging today operates at 3 levels each of which can contribute to the basic protection and preservation of the food:

1. the primary package (the one we take home from the shop) must be easily recognised, opened (and reclosed if necessary) and be compatible with the food;
2. the secondary packaging (the one received by the shop) groups the primary packages into handleable size and weight to facilitate shipping, display and sale;
3. and the tertiary packaging (transport packaging) which produces a unit load of standard size for bulk transport.

Packaging, therefore, fulfils many functions. It must:

• Contain or hold the food and keep it secure
• Preserve the original quality of the food
• Protect by preventing or minimising mechanical damage to the food
• Inform by helping to identify the product and provide legal and useful information on the use of the food (e.g cooking and storage).
• Assist handling and provide for convenient movement (necessary for all three levels of packaging).
• Packaging must also comply with food legislation and other relevant regulations.

The production of anything, including packaging materials, uses raw materials and energy, but both packaging material manufacturers and food manufacturers operate in an intensely competitive environment causing continual search for ways to minimise packaging costs without compromising the protection or presentation of the product.

Packaging also reduces waste. Most packaged fresh and processed foods have had the non-edible material (e.g. husks, peels, vegetable tops, bones of animal or fish etc) removed during preparation. As a result, those materials are used for animal feed or other purposes instead of going into domestic waste. Likewise, energy is saved by not having to transport that inedible material through the distribution and retail chain to the consumer. A World Health Organisation study has shown that without good packaging food wastage in the less developed regions of the world can reach between 30 and 50% while with good packaging it is rarely more than 2-3%.

Examples of recent reductions in materials and energy usage are:

• In 1970 a metal can for baked beans weighed almost 70gms. This was reduced by technical improvement in tinplate to 57gms by 1990. A metal can for coffee in the 1970s weighed over 130gms. Today's vacuum cans in aluminium, not tinplate, weigh less than 20gms;
• In the 1950s returnable glass milk bottles weighed nearly 400gms. Glass bottles for the same pint of milk today weigh some 200gms and are still returnable. Moreover changing to plastic coated paperboard (carton) packaging has reduced the material used still further;
• In 1983 a 1.5litre PET plastic soft drinks bottle weight 66g. Today the weight has beeen reduced to 42g;
• Non returnable (single trip) bottles for soft drinks use 20% less glass than returnables.

This process of 'lightweighting' continues for all forms of packaging and materials. Most food products can be packaged in a variety of materials and ways and food suppliers and manufacturers choose the most appropriate type of packaging for a product depending on the nature and requirements of the product, the degree and nature of the protection needed, the distribution system, the shelf-life, and the environmental impact.

Design of a package is a compromise between essential protection of the contents, e.g. extra robustness or airtight seals, and easy and convenient use including ease of opening. A really well-designed pack is one that strikes an effective balance between these two requirements. The degree of success varies with the nature of the package. A few packs in some batches will be more difficult to open and a number may be virtually impossible to open. However, this is usually because of a fault in the packaging machine or the quality control rather than the pack design. Manufacturers are increasingly aware of the special 'openability' problems encountered by customers with physical disabilities, and efforts to improve matters by better quality control will benefit all users.

The '3 R's' of environmental packaging law and practice are Reduce, Re-use and Re-cycle. These are the main ways of minimising the amount of used packaging in municipal waste disposal. As far as food packaging is concerned, the major packaging materials have to be considered and dealt with separately.

Glass, tinplate and aluminium, when recovered by re-cycling, perform similarly to the virgin materials. Re-cycling all three reduces overall energy usage (particularly with aluminium). Re-cycling schemes are now in operation for the recovery of both tinplate and aluminium containers. Glass containers (e.g. returnable milk bottles if sound) can be returned and re-used but single trip containers and broken glass ('cullet') are returned to the glassworks for re-cycling.

Used and discarded paper and paperboard packaging can also be recovered and re-cycled as can newsprint, tissues, and most grades of corrugated fibreboard cases.

Plastic materials present a variety of recovery and re-cycling problems. About half of all consumer goods are packaged in plastic of one kind or another, yet, because of its light weight it represents only 15% by weight in household waste. This means that it is economical of materials and energy for transport of goods packed in plastic. Most individual plastic packages (without counting the weight of the contents) weigh less than 10g and some of these are also contaminated with food residues such as yogurt, fats, cream and similar products. The light weight also makes it more difficult to collect and transport for re-cycling. Lightweight films, bags, pouches, etc made of plastics or plastics/paper laminates are probably better incinerated to recover energy particularly if they are contaminated.

There are several requirements for a re-fillable system to work:

• consumers must be made aware of which containers are returnable;
• the operation is local, centred around each filling plant with a radius of about 50-80 km;
• the transport system for delivery and returns is preferably controlled by the filling plant;
• the cost of returning the empty container and of washing and handling it must not exceed the cost of a single-trip container;
• the containers must be easy to return for refilling via convenient collection systems.

It is only when the package is emptied and needs to be disposed of that we notice it because much of it is light in weight but bulky. Also people are seldom aware of the role of the packaging in protecting the product in distribution until it is opened for use.

A UK Royal Commission on Environmental Pollution found that total packaging (not just food packaging) contributes 1% of the total of all solid wastes. Total household waste contributes only 4% of all solid wastes.

A study of waste by the US Chamber of Commerce indicated that the relationship between food waste and packaging waste was clear; as packaging use (and subsequent disposal as waste) increases, food wastage decreases.

The packaging material has both to preserve the food and to protect it from deterioration, outside contamination or damage during distribution and storage. In addition, the packaging material in direct contact with the food must not itself harm, or be harmed by, the food. Packaging materials for a particular food must therefore be carefully selected with these considerations in mind.

As in the UK and Europe, most countries have developed strict controls, based on extensive testing, for the use of 'food contact' materials; and these help to ensure that a correct choice is made.

Food science is the scientific understanding of the composition of food under various conditions. But this seemingly straightforward definition hides a complex multidisciplinary subject involving a combination of several sciences and a knowledge of the composition of food materials and their physical, biological and biochemical behaviour including:

• interaction of food components with each other and/or with other elements or materials (e.g. oxygen, packaging materials)
• nutrition
• enzymology
• microbiology
• pharmacology and toxicology, and
• the effects of manufacturing, processing and storage.

Food technology is the application of food science to the processing of food materials into safe, wholesome, nutritious, tasty and attractive food products. Food technology draws upon and integrates the application of other technologies to food, such as packaging, materials science, engineering, instrumentation, electronics, agriculture and biotechnology.

No. It is the scientists and technologists, working in research establishments, in industry, as consultants to industry, and in enforcement and government agencies, who

• extend the frontiers of knowledge about the properties and behaviour of food;
• apply increasing knowledge to the development of the present (and future) wide variety of safe and attractive foods;
• design and operate quality assurance systems to ensure that quality and safety are maintained during the manufacture, distribution and retailing of foods;
• operate surveillance systems to ensure that legal, quality and safety requirements are being met.

Personal opinions vary in every walk of life, but scientists disagree far less than is often suggested. However, at the 'cutting edge' of scientific research, there can be genuine disagreements on the validity or interpretation of available information and on how new research findings may affect previous interpretations. Scientists are accustomed to debating these matters, and it is in the course of thrashing out these differences and highlighting gaps of knowledge where further research is needed, that scientific knowledge advances.

No. Hindsight shows that the experts nearly always "got it right". It's simply that we only notice the rare instances where they did get it wrong. And in those instances, we have to ask why. Sometimes the scientists were in fact right, but human error occurred in applying that knowledge. Sometimes it was that the knowledge available at that time was insufficient. Scientists are not magicians. Twenty years ago they knew only a fraction of what we know now; which in turn is only a small fraction of what we will know in a few years time. Research brings new knowledge all the time and at an accelerating rate.

Our profession is the repository of existing knowledge in the field of food science and technology, and includes those researchers expanding the boundaries of that knowledge and the experts applying it for a safe, wholesome, nutritious and attractive food supply for the public benefit.