1 October 2019


These days, processed food seems to be associated with either “junk food” or food additives – things that many people would rather avoid if they could. Prof Jennie Brand-Miller reminds us that food processing is nothing new. It’s something our paleolithic (stone age) ancestors were doing long before the agricultural revolution some 12,000 years ago. Just imagine all the trial and error that went into discovering how to leach toxins from plant foods. Perhaps, we should see food processing as an example of human creativity at its best she suggests.

Stone-grinding of seeds and leaching of toxins from plant foods have been practised for thousands of years. Many fruits dried naturally on the bush or tree (think dates, figs and sultanas) making them ‘shelf stable’ for years. We know that Australia’s Indigenous people for example collected one particular variety in large quantities, mashed and shaped them into a ball and placed them high up in a tree to protect them from animals. These energy-dense snacks were a safe and reliable treat during the following season. In “Transforming the Inedible into the Edible,” Anna Teuchler, Asa Ferrier and Richard Cosgrove describe how the Indigenous people in far northeast Queensland leached the toxins from rainforest tree nuts, a dietary staple, several thousand years ago (see Read More).

Anyone who farms even on a small scale in their backyard knows that fruit and vegetables are seasonal. They ripen in gluts and we give half away. But being the creative creatures that we are, we developed ways to extend the storage life of most foods. Sun drying of fruit, fish and seaweeds, pickling of vegetables in vinegar and brine and salting of meat, were early processing techniques. We also learned that nitrate salts added to meat gave them not only longer storage life, but a nice pink colour and delicious flavour as well. Hams, bacon and salami are still on the menu made using age-old techniques of processing.

Dried fruit
In time, we learned to bottle fruit and vegetables, cooking them first, sealing them carefully and raising the temperature as high as possible to kill bacteria and fungi that would inevitably contaminate fresh food. Eventually, the food industry took over from the homemaker, developing more reliable sterilisation techniques that prevented the growth of botulinum spores. Botulism was a dreaded phenomenon – just a single lick of the finger was enough to poison violently and often kill.

The chemical and physical processes that are used by the food industry are more often than not identical to those we use in the kitchen – heating, toasting, blanching, boiling and freezing, just on a much larger and more efficient scale. Without modern methods of processing that permit long-term storage, we would otherwise waste a huge proportion of any seasonal harvest. The excess food would be thrown away, causing surges in pests like locusts, mice and rats and creating smelly streets full of vermin and garbage. And food scarcity, vitamin deficiency and even death in winter and spring were not uncommon.

Finally, where would we be without the creativity of those early farmers who milled wheat and other grains into flours to make delicious breads, cakes and biscuits? Dairy farming also made use of lactating cows (and goats, sheep and camels), who were capable of producing more than enough milk for ¬their offspring. This highly nutritious product gave rise through natural selection to whole populations with the ability to digest lactose, the sugar in milk. And it wasn’t long before early farmers processed excess milk into forms that could be stored and accessed in times of scarcity (think cheese and other fermented dairy products), even by those with lactose intolerance. How dull our diet would be without yogurt, feta, parmesan and the hundreds of other soft and hard cheeses we enjoy throughout the year.

In Australia, we have a relatively short list of permitted food additives that are governed by strict food laws. They are permitted in specific foods in specific quantities (not any food, nor any quantity). They must serve a technological need and must have been assessed for safety in much the same way as all drugs. Like sun drying, a preservative lengthens the shelf life of a food. The majority of food additives are identical to substances that occur in nature and serve the same purpose (e.g. lecithin in eggs is an emulsifier than keeps water and fats in a stable emulsion). Only flavours consisting of thousands of molecules have not been through the rigorous testing of other food additives. The same applies to the natural flavours we leverage in herbs and spices.

Read More: