Producing Enough Food Is Only Half the Battle - food preservation and world hunger

UN Chronicle, Winter, 1999 by Francois Mazaud

How true are the reports which claim that more than 40 per cent of food grown is lost before it is consumed, or if losses were reduced by 5 per cent, millions more people could be fed, or that food losses in some developing countries can amount to tens or even hundreds of millions of dollars? Sadly, many of these stories are true. However, because the factors that cause losses are so varied and take place at many stages of handling, processing and storage, the overall importance of the fully integrated problem is seldom realized. The year-to-year variation in losses is great and, therefore, generalizations are not particularly useful. A world average of 15 to 20 per cent of grain loss is probably close to accurate. If one takes the upper limit, the implication of this loss is that any or all factors which have contributed to the production are wasted. This means 20 per cent of land, 20 per cent of manpower (labour), and 20 per cent of inputs (seeds, fertilizers, etc.) are effectively wasted.

The problem of handling, preserving and storing grains and legumes predates organized agricultural production and has existed since people collected wild seeds. Even prehistoric people realized they had to preserve as much as they could of what they collected until fresh supplies became seasonally available again. The period of plenty does not always last long and, once it is over, it is necessary to subsist on what has been stored until the next harvest. It's a fact that everything--grains, meat, fruit, vegetables, nuts, berries and fodder for animals--seems to become available at about the same time. And food must be preserved form one season to the next and protected from predators, keeping it free of mould and in edible condition. In most societies, people still have to exist to a large extent on what they have grown and stored.

One big change from the distant past is that the chain from producer to consumer is usually made up of specialized components even if it is not fully integrated. Everyone wants to buy at the lowest possible prices and sell at high prices, so people at each stage look for alternatives elsewhere. The producer is usually looking for quantity; intermediate players and consumers normally demand quantity and quality, but each usually wants a different aspect of quality.

Many of the necessary are laborious and take a lot of time and energy, and so the price goes up as the commodity passes through each link of the chain.

The problem is continuously changing, as more emphasis is placed on making good quality food available at a low price, but the intermediate steps of production, handling, processing and storage inputs are demanding higher rates.

Physical losses are the most evident problems in the post-harvest chain--insect larvae boring out the centre of a grain, pigeons eating the whole grain of squirrels taking seeds to store for later consumption. However, losses also occur in many other ways, some of which are quite difficult to detect. There can be losses of quality, which means a loss of nutrients, or there can be contamination and the formation of substances such as mycotoxins that can seriously endanger the human health. These qualitative and quantitative post-production losses require specific interventions which, if not properly carried out, could lead to death due to food poisoning or starvation.

Farmers do have some measure of control when it comes to food production--the provision of fertilizer and water or selection of seeds, for example. However, there is little that can be done about some natural occurrences that affect production, such as severe droughts, floods or pests outbreaks. Losses of grains and legumes can be reduced in a number of ways: the more resources that can be spent on preserving and increasing the shelf life of grains and legumes, the lower the losses are likely to be, although it is not realistic to expect eliminating losses entirely. Nowadays, insects are mostly controlled by chemical insecticides, although there are other ways to control them--natural products, reduction of the moisture content of the grain, smoking and adding fine powders to the grain (like sand or ash) have all been used successfully. The predation of other animals is best controlled by physically excluding the particular predators concerned. Perhaps the worst form of damage, which is probably the easiest t o control, is that from micro-organisms. Proper drying and storage of grain will almost entirely elimiante microbiological activity, and properly dried grains will not germinate if they are maintained in good condition.

How to make rational improvements

As we have seen, the improvement of the post-harvest system is not simply a technical problem but a combination of various elements which need to be improved together. Very often, the technical component alone is not the most important solution. We already know how to reduce losses, but perhaps the most important point of all is making this knowledge more accessible to the people who need it in a way that they can understand and use. In recent years, many research and training institutions have devoted considerable resources to improving the inter-related aspects of the post-production system of the main staple crops. This has resulted in the accumulation of a significant amount of practical experience and useful technical information. Literature reviews on existing information in the post-production system have shown that, although huge amounts of information are available, it is not accessible in a form that can be easily transmitted for wider circulation.