Cereals: Novel uses and processes

Cereals: Novel uses and processes

Bioresource Technology 63 (1998) 283-284 © 1998 Published by Elsevier Science Limited All rights reserved. Printed in Great Britain 0960-8524/98 $19.0...

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Bioresource Technology 63 (1998) 283-284 © 1998 Published by Elsevier Science Limited All rights reserved. Printed in Great Britain 0960-8524/98 $19.00 ELSEVIER

P11:S0960-8524(98)00167-3

Book Review Bioplastics This is familiar ground, but steady progress is being made with the use of starch as a filler to reduce the cost of biodegradable plastics, particularly with the increased ability currently available for controlling water sensitivity of coatings. There is the dual problem of sticking the coating to the starch grain and preventing the ultimate composite from being prematurely degraded by water. The filler concept is far from new, but there have been advances, reviewed by US participants, in overcoming the second problem.

Cereals: Novel Uses and Processes. G. M. Campbell, C. Webb and S. L. McKee (eds). 289 pp. ISBN 0-306-45583-8. Price $96. Hardback.

The proceedings of an international conference on cereals: novel uses and processes. Held 4-6 June 1996, in Manchester, United Kingdom. Do not be put off by the title, which is not in itself very specific, in spite of the use of the word 'novel'. An immediate reaction is to think 'Not descriptions of new types of cornflakes, or an excuse for the Common Agricultural Policy (CAP) practitioners to explain the use of, and then sureptitiously eliminate, the cereal mountains. Cereals have justifiably had a bad press in recent years, because of the tax-payerparasitic subsidies their production has entailed. This volume is a well organised and well edited text covering the gamut of the state of the art techniques of (predominantly) wheat processing, but with a brief mention of corn (maize), barley, rice, sorghum (great mil]et) and, somewhat strangely, buckwheat. In a 'greenhouse' world the inclusion of these two last named harsh-environment crops is apposite. There are limits to turning sows ears into silk purses even with all the alchemy of genetic engiz neering. The aspiration of a world fed on rice, wheat and maize along may be fading. There is no shortage of research workers on cereals, taken on a worldwide basis, and the organizers are to be congratulated on the selection of speakers. It would have been easy to dominate the symposium with company-based personnel, as is the practice of the pharmaceutical industry. This has not been done, although international names such a CPL Scientific, Dalgety, and Kellogg appear in the list of sponsors with indirect commercial sponsorship via the Satake Centre of the Manchester Institute of Science and Technology. The EEC has given support under the European Commission FLAIR research proramme, as have the UK Government's Silsoe Research Station and the Danish Institute of Biomass Utilization and Biorefinery. Although predominantly from Europe, the participants came from some 20 countries, from China and Zimbabwe to New Zealand and the USA.

Fermentation Of the non-food half about one fifth is converted to other products by fermentation, with somewhat less for non-fermentation processes, such as polyols, vitamins and other chemicals. Much of this more detailed breakdown is for the UK sector. A broader world picture is given by Coombs and Hall, in which they touch on the controversial subjects of bio-(fuel grade)-ethanol and the biodegradation of cellulose. These topics are considered in more detail in the second section which is devoted to integrated bioprocesses. The highly unflattering economic analyses by Audsley and Sells of some of the techniques being currently advocated make salutary and, in the reviewer's opinion imperative, reading. Fermentation uses of starch to other products than alcohol are expanding rapidly, thanks in no small measure to advances in the genetic engineering of microorganisms. Interest in PHB(poly-hydroxy-butyric acid has now swung to the production of co-polymers with polyhydroxyvalerate). Yet another route to useful (viz economically feasible) biogradable plastics is by using the large surplus of gluten on the market for the production of plastics, coating the protein with less water-soluble, less permeable, coatings. These techniques, some of which are recent and appear very promising, have been listed by Kolster and others. Harvesting cereals unripe Another group of cereal-derived compounds of increasing use is the fructan group, particularly using cereals at the 'milky' stage for production of these products. This unripe stage may be selected by choice, for areas where complete ripening of the grain is difficult, or due to unexpected fluctuations in the weather, a consequence of entry into the now recognised greenhouse world. D'Egidio and others

Starch Naturally, accounts of the uses and modification of starch take precedence. Starch is the doyen of the biotechnologists' feedstocks. Professor Howling's introductory paper shows how approximatley half the 5 million tonnes of starch used in Europe each year is for non-food purposes. 283

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list a number of recent studies on the usefulness of fructans in both human and animal nutrition. As is to be expected, attention is paid to the bran and straw fractions and to developments in sourdoughs, lactic acid fermentations, LAB starter cultures, methane and malts. An account of the PeriTec modification of the time honoured milling process is presented by Foster of Satake, its virtue over conventional milling lying in the prior tempering and debranning of the grain, giving rise to a improved efficiency of bran separation via an enhanced rate of water uptake of the debranned cereal, thus halving the process time. The promoters claim this process to be the milling system for the 21st century. Time will tell. Man cannot live by bread alone Whilst the content of this symposium has been directed to the fine-grain cereal harvest, much that has been said might apply equally, or even advantageously, to the coarse-grains. International enthusiasm for wheat is, in the reviewer's opinion, misplaced and in sub-saharan Africa this enthusiasm is one of the worst effects of the zeal for the industrial world's (viz 'western') technology transfer. Beta and Zama of Zimbabwe University have reviewed the range of food products currently being developed from sorghum and its fractions. Not only is this promotion of sorghum a practical innovation but it is a real contribution to food security in Africa in the next century. Pseudo-cereals Another group of food-security crops, mentioned at the symposium by Carlsson and Kalmar University,

Sweden, is that of the amaranths and chenopods, that is 'the pseudo-cereals'. The grains of these crops are richer in protein than the cereals, with a better amino-acid balance and higher fat than cereals and with good vitamin and mineral characteristics. Even the phenolic components are not solely deleterious. Their great virtue, from an agronomic viewpoint, lies in their being able to grow in harsh, dry and saline environments. The organizers may be forgiven for including them in a cereal symposium. Conclusions Much of the information and many of the enzymic, microbial fermentation and physico chemical techniques mentioned in the present volume might also be applied to the processing of non-cereal starchy staples, such as tapioca/cassava, the 'irish' potato and sweet potato and the old staple of Southeast Asia, sago, which like the amaranths is currently receiving attention as a 'greenhouse world' crop. The reviewer makes no apology for reiterating this food security aspect of the deliberations. Attitudes to food crop choice, production and processing are going to have to change at a hitherto unaccustomed rate. Altogether, with its good index, this is a strongly recommended addition to the literature on starchy staples and should have a readership wider than those who are concerned with the previously cited bread alone. It is an inspiration for the dictators of food production policy in a demographically and climatically increasingly turbulent world. W. R. Stanton