Food, feed and fermentation: the future for grain processors
March 01, 1996
by Teresa Acklin
The first of two parts discusses current uses and the potential for grain and flour in industrial and other non-food sectors.
By Colin Webb
Few things are certain when it comes to trying to predict the future for grain processors, particularly in terms of the likely industrial uses of whole grain and flour. However, it is an undisputable fact that as long as we're human the vast majority of our material needs will be food-related. Whatever else happens, therefore, it is most likely that the primary purpose for processing grain will be to produce food and/or feed.
Nevertheless, there is also an undeniable inevitability that one day many of the finite resources we currently use to produce chemicals and energy will no longer be available. Industry will be obliged to turn to renewable resources as replacement raw materials.
Whether that time comes in the next decade, the next century or the next millennium will be the subject of continuing and increasing debate. What will drive industry to adopt new raw materials, such as cereal grain, will be the relative economics associated with obtaining and processing those materials compared with traditional feedstocks.
The notion of using grain to produce industrial chemicals is not new. Almost three quarters of a century ago, a movement was launched to employ renewable agricultural resources. The so-called chemurgy movement was quite successful until it was effectively buried under the avalanche of the petrochemicals industry. Given the inevitability of an eventual return to renewable resources, however, the revival of the chemurgy movement is set to become a feature of the third millennium.
So what industrial uses of grain can producers and processors look forward to in the future? Before considering this it is worth looking at current usage of cereal produce (see table on page 21).
A clear hierarchy exists in end use, with food being more important (higher value) than feed. Thus, in principle, it is rejected food that gets used for feed and, in the same way, material not good enough for feed (or material which is surplus to requirements) might get used for industrial chemical production.
At the bottom of the chain is energy if you cannot do anything else with grain, burn it! Wheat flour, incidentally, has a calorific value around half that of coal, so technically this is quite feasible, though one might prefer a more value-added product.
A survivor of the chemurgy movement is the production from oat and maize residues of furfural, a liquid used in making plastics and as a solvent. A whole branch of chemistry is based on furfural, the chemical derivation of which is analogous to, but considerably less harmful than, petroleum-derived benzene.
STARCH USE DOMINATES. The biggest non-food user of cereal grains, however, is the starch industry. Starch is extracted from the endosperm after first milling, either wet or dry. Traditionally, maize has been the favored cereal for starch production but, with the added value of gluten as a byproduct, wheat is becoming an increasingly attractive alternative, particularly in those parts of the world where maize is not a major crop.
Starch finds a wide range of uses in diverse industries, but much of it returns to the food chain in the form of texturing agents, fillers and humectants and as glucose and fructose syrups. The rapid growth of the starch-derived syrups market (due largely to its acceptance in soft drinks manufacture) has been one of the major successes in grain processing in recent decades.
The major non-food use of cereal starch is in papermaking which, in Europe alone, accounts for more than 1.2 million tonnes per year, approximately half of all non-food consumption. Starch fulfills several functions in papermaking: it increases the internal strength of the paper, it acts as a retention aid for fillers and fine material, it is a key agent in surface treatments (sizing), and it acts as a binder in paper coating. Furthermore, it is likely that the future will see increases in the use of starch in the paper industry, through greater levels of fillers being incorporated into raw stock and through further increases in the use of coatings.
Other nonfood industries currently using cereal starch include:
the pharmaceutical industry, for binding, coating and filling
the paint industry, as gelling agents;
the chemical industry, where starch-derived products take part in chemical reactions;
the plastics industry, as a filler, particularly in biodegradable plastics;
the agrochemical industry, as seed coatings and binders;
the environmental control industry, as a flocculent to reduce metal ion concentrations during effluent treatment;
and the fermentation industry, as a carbohydrate energy source.
Of all these, the most exciting prospects for the future surely lie with the fermentation industry. Inextricably linked to the biotechnology revolution, the fermentation industry is poised to become the supplier of an almost limitless range of products.
These will include both entirely new products and replacements for existing products which are currently based on nonrenewable raw materials and environmentally harmful processes. Unlike chemical processes, fermentations benefit from the use of complex, natural, raw materials. In essence, fermentation can be regarded as the chemical industry equivalent of farming.
What defines the final product is not the raw materials but the organism that is cultivated during the fermentation. The production vessel is supplied with nutrients in the form of carbon, nitrogen and other materials such as minerals and vitamins (and occasionally light). It is then seeded with the chosen microorganism, which grows and produces the desired product. With the number of possible microorganisms ranging into the hundreds of thousands (and being added to at increasing rates), the variety of potential products is enormous.
Part two takes an in-depth look at the future of grain use in the biotechnology sector.
Dr. Colin Webb is professor of grain process engineering and Director of the Satake Centre for Grain Process Engineering at the University of Manchester Institute of Science and Technology.Current uses of cereal grains
|Flour||Bread, biscuits, cakes, pasta|
|Starch||Foods, industrial chemicals|
| ||Gluten||Foods, industrial chemicals|
|Rice||Food||Table, breakfast cereals|
| ||Starch||Glucose & fructose syrups|
Industrial uses of grain will be explored more fully at “Cereals: Novel Uses and Processes,” a conference to be held on June 5-6, 1996 in Manchester, U.K. For more information, contact Dr. Grant Campbell, University of Manchester Institute of Science and Technology, Department of Chemical Engineering, P.O. Box 88, Manchester M60 1QD U.K.
Phone: 44 1961 200 4472; fax: 44 161 20 4399; e-mail: email@example.com.