Get the answer of: Why is Food Preservation done?
From the earliest times, storage of stable nuts and grains for winter provision is likely to have been a feature shared with many other mammals but, with the advent of agriculture, the safe storage of surplus production assumed greater importance if seasonal growth patterns were to be used most effectively.
Food preservation techniques based on sound, if then unknown, microbiological principles were developed empirically to arrest or retard the natural processes of decay.
The staple foods for most parts of the world were the seeds – rice, wheat, sorghum, millet, maize, oats and barley – which would keep for one or two seasons if adequately dried, and it seems probable that most early methods of food preservation depended largely on water activity reduction in the form of solar drying, salting, storing in concentrated sugar solutions or smoking over a fire.
The industrial revolution which started in Britain in the late 18th century- provided a new impetus to the development of food preservation techniques. It produced a massive growth of population in the new industrial centres which had somehow to be fed; a problem which many thought would never be solved satisfactorily.
Such views were often based upon the work of the English cleric Thomas Malthus who in his ‘Essay on Population’ observed that the inevitable consequence of the exponential growth in population and the arithmetic growth in agricultural productivity would be over-population and mass starvation.
This in fact proved not to be the case as the 19th Century saw the development of substantial food preservation industries based around the use of chilling, canning and freezing and the first large scale importation of foods from distant producers.
To this day, we are not free from concerns about over-population. Globally there is sufficient food to feed the world’s population, estimated to be 5300 million in 1990.
World grain production has more than managed to keep pace with the increasing population in recent years and the World Health Organization’s Food and Agriculture Panel consider that current and emerging capabilities for the production and preservation of food should ensure an adequate supply of safe and nutritious food up to and beyond the year 2010 when the world’s population is projected to rise to more than 7 billion.
There is however little room for complacency. Despite overall sufficiency, it is recognized that a large proportion of the population is malnourished. The principal cause of this is not insufficiency however, but poverty which leaves an estimated one-fifth of the world’s population without the means to meet their daily needs.
Any long-term solution to this must lie in improving the economic status of those in the poorest countries and this, in its train, is likely to bring a decrease in population growth rate similar to that seen in recent years in more affluent countries.
In any event, the world’s food supply will need to increase to keep pace with population growth and this has its own environmental and social costs in terms of the more intensive exploitation of land and sea resources. One way of mitigating this is to reduce the substantial pre- and post-harvest losses which occur, particularly in developing countries where the problems of food supply are often most acute.
It has been estimated that the average losses in cereals and legumes exceed 10% whereas with more perishable products such as starchy staples and vegetables -the figure is more than 20% – increasing to an estimated 25% for highly perishable products such as fish.
In absolute terms, the US National Academy of Sciences has estimated the losses in cereals and legumes in developing countries as 100 million tonnes, enough to feed 300 million people.
Clearly reduction in such losses can make an important contribution to feeding the world’s population. While it is unrealistic to claim that food microbiology offers all the answers, the expertise of the food microbiologist can make an important contribution.
In part, this will lie in helping to extend the application of current knowledge and techniques but there is also a recognized need for simple, low-cost, effective methods for improving food storage and preservation in developing countries. Problems for the food microbiologist will not however disappear as a result of successful development programmes.
Increasing wealth will lead to changes in patterns of food consumption and changing demands on the food industry. Income increases among the poor have been shown to lead to increased demand for the basic food staples while in the better-off it leads to increased demand for more perishable animal products.
To supply an increasingly affluent and expanding urban population will require massive extension of a safe distribution network and will place great demands on the food microbiologist.