In food processing, harvested crops or butchered animals are used as the raw ingredients for making and packaging food products that are attractive, marketable and have long-shelf lives.

Attractive means that the product both tastes and looks good. To be marketable, it must match the kinds of food being demanded by consumers. Food products that have a long-shelf life reduce the costs of wastage for producers, distributors and retailers.

Development of food processing

Food processing dates back to our prehistory — when fire was discovered and cooking invented. The various ways in which food can be cooked are all forms of food processing.

Food preservation also began in prehistory, and the first ‘long shelf-life’ foods were produced by drying food in the sun and by preserving food with salt. Preservation with salt was common with soldiers, sailors and other travelers until canning was invented in the early 19th century.

The ancient Bulgarians invented the first instant food (bulgur) nearly 8.000 years ago, when found a way to parboil and dry whole wheat so that the grain only has to be reheated before it can be eaten.

One of the first ready-to-eat meals was devised by the ancient Celts when they invented the haggis and what is now known as the Cornish pasty.

Another processed food, cheese, was invented by the nomads of Arabia when they noticed how milk curdled as they jogged along all day on their camels and ponies.

The prehistoric methods of cooking and preserving food remained largely unchanged until the industrial revolution.

The development of modern food processing technology began in the early 19th century in response to the needs of the military. In 1809 a vacuum bottling technique was invented so Napoleon could feed his troops. Canning was invented in 1810 and, after the makers of the cans stopped using lead (which is highly poisonous) for the inner lining of the tins, canned goods became common throughout the world. Pasteurisation, discovered in 1862, advanced the micro-biological safety of milk and similar products significantly.

Cooling decreases the reproductive rate of bacteria and thus the rate at which food spoils. Cooling as a storage technique has been in use for hundreds of years. Ice-houses, packed with fresh snow during the winter, were used to preserve food by chilling from the mid-18th century onwards and worked fairly well most of the year round in northern climates.

Commercial refrigeration, using toxic refrigerants which made the technology unsafe in the home, was in use for almost four decades before the first domestic refrigerators were introduced in 1915.

Fridges in the home gained wide acceptance in the 1930s when non-toxic and non-flammable refrigerants such as Freon were invented.

The expansion of the food processing industry in the second half of the 20th century was due to three needs:(a) food to feed the troops efficiently during World War II, (b) food that could be consumed under conditions of zero gravity during forays into outer space, and (c) the pursuit of the convenience demanded by the busy consumer society.

To respond to these needs food scientists invented freeze-drying, spray-drying, and juice concentrates among a host of other processing technologies. They also introduced artificial sweeteners, colouring agents and chemical preservatives. In the closing years of the last century they came up with dried instant soups, reconstituted juices and fruits, and the ‘self-cooking’ meals (MREs) so beloved of military brass but not the grunts.

The ‘pursuit of convenience’ has lead to the expansion of frozen foods from simple bags of frozen peas to juice concentrates and complex TV dinners. Those who process food now use the perceived value of time as the foundation of their market appeal.

Benefits of processed foods

Initially, processed foods helped to alleviate food shortages and improve overall nutrition by making new foods available globally. Modern food processing delivers many additional benefits:

• De-activating the pathogenic micro-organisms found in fresh vegetables and raw meats (such as salmonella), reduces food-borne diseases and makes food safer.
• Because processed foods are less susceptible to spoilage than fresh foods, modern processing, storage and transportation can deliver a wide variety of food from around the world, giving us choices in our supermarkets that would have been unimaginable to our ancestors.
• Processing can often improve the taste of food, though it can also have the opposite effect.
• The nutritional value of food can be increased by the addition of extra nutrients and vitamins during processing.
• The nutritional value can also be made more consistent and reliable.
• Modern processing technologies can also improve the quality of life for people who have allergies by removing the proteins that cause allergic reactions.
• The mass production of food means that processed foods are much cheaper to produce than the cost of making meals from raw ingredients at home.

Processed foods are also extremely convenient. Households are freed from the time-consuming tasks of preparing and cooking foods that are in their natural state… the food processing industry makes everything from peeled potatoes ready for boiling to prepared-meals that just have to be heated in a micro-wave oven for a few minutes.

Hazards

Processed foods are undoubtedly a great boon. But all is not sweetness and light.

Generally speaking, fresh unprocessed food will contain a higher proportion of naturally occurring fibre, vitamins and minerals than the same food after processing by the food industry. Vitamin C, for example, is destroyed by heat and so fresh fruit will contain more vitamin C than canned fruit.

Indeed, nutrients are often deliberately removed from food during processing in order to improve taste, appearance or shelf-life. Examples include bread, pasta and ready-made meals.

The result is empty calories. Processed foods have a higher ratio of calories to other essential nutrients than fresh, unprocessed foods. They are often energy-dense while being nutritionally poor.

Processing can introduce hazards that are not found in unprocessed foods, due to additives, preservatives, chemically-hardened vegetable oils or trans-fats, and excessive sugar and salt. Indeed, the additives in processed foods… flavourings, sweeteners, stabilisers, texture-enhancing agents and preservatives among other… may have little or no nutritive value, or may actually be unhealthy.

Preservatives used to extend shelf-life, such as nitrites or sulphites, may lead to ill-health. In fact, the addition of many chemicals for flavouring and preservation has been shown to cause human and animal cells to grow rapidly, without dying off, thus increasing the risk of a variety of cancers.

Cheap ingredients that mimic the properties of natural ingredients, such as trans-fats made by chemically-hardening vegetable oils that take the place of more-expensive natural saturated fats or cold-pressed oils, have been shown to cause severe health problems in numerous studies. But they are still widely used because of their low-cost and consumer ignorance.

Sugars, fats and salts are usually added to processed foods to improve flavour and as preservatives. As diabetics, we are all well aware of the effects of excessive sugar, fat and on our already damaged systems. Eating large amounts of processed food means consuming too much sugars, fats and salts, which, even if you a in full health, can lead to a variety of problems such as high blood pressure, cardiovascular diseases, ulcers, stomach cancer, obesity, and of course diabetes.

Another problem with processed foods is that, where low-quality ingredients are used, this can be disguised during manufacturing.

In the processing industry, a food product will go through several intermediate steps in independent factories before it is finalised in the factory that finishes it.

This is similar to the use of sub-contractors in car manufacturing, where many independent factories products parts, such as electrical systems, bumpers, and other sub-systems, in accordance with the final manufacturer’s specifications. These parts are then sold to the car plant where the car is finally assembled from the bought-in parts.

Because the ingredients in processed foods are often made in large quantities during the early stages of the manufacturing process, any hygiene problems in the facilities that produce a basic ingredient that is used widely by other factories in the later stages of production can have serious effects on the quality and safety of many final food products.

Despite the hazards, everyone eats processed foods almost exclusively nowadays. As a result, people eat more quickly and no longer seem aware of the way food is grown and how it is a gift of nature.

It seems to me, also, that food has become more of a necessary interruption in our busy lives and less of a social occasion to be enjoyed.

Eating processed foods

You can’t get away from eating some processed foods… the convenience is irresistible.

When you eat processed foods you reduce the likelihood of being poisoned or picking up a food-borne disease. The nutritional value of what you eat may be more consistent and you will probably be ingesting more nutrients and vitamins than you would get by eating only unprocessed food.

On the other hand, by eating processed foods you are exposing yourself to a potential loss of heat-sensitive vitamins and nutrients that are removed to improve shelf-life, taste and appearance. You are also exposing yourself to the potential adverse effects on your health of various additives and preservatives, some of which can be very serious indeed.

The calorie-dense nature of processed foods, due to the large quantities of sugars and fats they contain, makes them extremely problematic for diabetics and those with high cholesterol and blood pressure levels.

The only solution is to choose the processed foods you buy with extreme care — by reading the labels on the packaging — and to focus your diet on fresh or frozen produce as much as possible.