Previous - Next
This is the old United Nations University website. Visit the new site at http://unu.edu
Plant proteins for human food
The
family Rice Bowl
Brief
reviews
Plant Proteins for Human Food: Proceedings of a European Congress Held in Nantes, France, October 1981. Edited by C. E. Bodwell and L. Petit. Martinus Nijhoff/Dr. W. Junk, The Hague, Netherlands, 1983.267 pp.
As the world population moves inexorably upwards to an expected six billion by the year 2000 and eight billion by 2025, not only will the needs for plant protein expand in order to keep pace with this population increase, but the proportion of plant protein to total protein is also likely to increase as economic, energy, and agricultural constraints limit increases in animal protein production. Although primary protein deficiency is less widespread than was previously believed, the provision of adequate protein in the dietary is still a major aim in nutrition.
As the editors of this volume state, "adequate supplies of dietary protein do exist if all the plant protein which is produced each year and is edible for humans were actually consumed in an equitable manner by the human population." This is unlikely to occur in practice, since a large proportion of the available edible plant protein will continue to be fed to livestock. They conclude that "for major shifts to occur in the utilization of plant protein, suitable vegetable protein products must be developed. Some are, or will be, similar to and competitive with animal protein products as desirable components of the diet. In addition, however, it is very important that new products be developed that will be accepted as preferred food items on their own merit and not merely exist as imitations or extenders of animal protein products." The book is thus timely and important.
Part 1, "World Protein Supplies: The Role of Plant Protein," evaluates the supply of both animal and plant proteins. It advances the thesis that increased production of plant proteins alone will not be enough and that plant protein products should be developed that will have attributes and advantages of their own and will thus be able to compete with animal protein sources. Part II, "Composition of Raw Materials," discusses the protein and amino acid composition of cereals, legumes, and oilseeds and considers the storage proteins of legumes and the potential for genetic improvement of legume proteins.
Part III, "Extraction Processes and End-Product Characteristics," consists of four papers on procedures for the extraction of protein from legumes, from oilseeds, and from leaves. The case of tobacco is of interest: In research seeking (a) to obtain smoking material with reduced toxicity and (b) to extract protein for human consumption from tobacco leaves, Tantozzi and Sensidoni found that protein extraction not only allowed production of a smoking material of acceptable quality but also reduced the toxic nature of its smoke.
The functional properties of vegetable proteins are discussed in the five papers of part IV. Among the topics considered are protein functionality and its relation to food micro-structure, the comparative physical and chemical aspects of vegetable protein functionality, and the effects on these of extraction processes, the improvement of functionality by controlled enzymatic hydrolysis, and finally, the various technological processes that can be used. Among the latter, the importance of combining animal and vegetable proteins is stressed, since such combinations are believed to have considerable advantages from the organoleptic, textural, nutritional, and economic standpoints. This emphasis implies that present techniques using plant protein sources alone suffer from limitations. Indeed, it is stated bluntly that no "ideal process," i.e., one that is economical, efficient, and capable of supplying high quality textured plant materials, is likely to be developed in the near future.
The final section of the book, part V, consists of two papers on nutritional issues. One reviews the influence of processing on the nutritional value of proteins, concentrating on the major chemical effects of processing on overall protein value. These effects include denaturation, crosslinkages, and reduced amino acid availability consequent on the Maillard reaction. The other paper reviews the natual antinutritional factors present in European plant proteins. These mostly originate from legume seeds and include heterosides such as phaseolunatine from lima beans that can break down to HCN, toxic amino acids such as ß-oxyalylaminoalanine from Lathyrus sativus, haemagglutinins, mineral chelating compounds such as physic acid, and miscellaneous others, including flatulence-producing factors.
Overall, this is a worthy volume that includes much material of interest and concern to nutritionists and food scientists. It is nevertheless disppointing that, despite the importance of the area, it contains very little that could be considered innovative, and several relevant concepts of consequence do not appear to be discussed. One of these directly relates to an important plant protein, gluten. A major recent trend in several regions of the world has been a large increase in Western-tome soft bread consumption, probably both for its convenience and for its identification with "progress." However, wheat grows best in temperate climates, thus causing not only potential balance-of-payment problems but also increasing dependence on North American production. Such major changes in con gumption patterns and dependence could have staggering implications over the next few decades. Gluten-forming abilities may be able to be bred in other cereals, but interim solutions will involve bread production from composite flours. There is a major potential research area involving plant proteins, especially in relation to plant breeding, but the issue is not even mentioned.
Other omissions include any detailed consideration of cooking quality, digestibility, and storing qualities of legume seeds that currently limit their wider use and may have solutions in both the fields of plant breeding and food technology. Although the title of the book includes the words "plant proteins," it also includes "human food" and perhaps too much consideration is given to the former at the expense of the latter. In industrialized countries, animal proteins serve not only as sources of essential amino acids but also as major sources of other nutrients such as minerals and vitamins in readily available forms, e.g. haem iron. Other than brief consideration of the mineral chelating properties of certain plant proteins, little attention is paid to potential problems that could arise concerning other nutrients were animal protein to be replaced in dietaries by plant proteins. In addition to these omissions, other criticisms could include the lack of an index, the dual page numbering {the volume is reprinted from Qualitas Plantarum: Plant Foods for Human Nutrition, vol. 32, nos. 3 and 4), which is sometimes confusing, and some rather stilted English usage in several articles translated from French originals.
Recognizing these limitations, and perhaps the prejudices of the reviewer, the book is broad in scope; most chapters are well referenced; and it does supply detailed information that will make it useful to a wide range of readers, especialIy in the fields of food technology and food science.
Peter L. Pellett
Department of Food Science and Nutrition
Chenoweth Laboratories
University of Massachusetts
Amherst, Massachusetts, USA
The Family Rice Bowl. By Elisabeth Croll. Zed Press, London, 1983.375 PP.
The virtual elimination of malnutrition and periodic famine from the People's Republic of China is surely one of the extraordinary achievements of this century. China now provides at least the minimal nutritional requirements for the quarter of the world's population that lives within its borders, in spite of the fact that only 15 per cent of its land is potentially cultivable. Because of the intrinsic interest of this accomplishment, and because of lessons that might be learned for other developing countries that have not been so successful, the United Nations Research Institute for Social Development initiated a series of investigations of the Chinese experience. This monograph is the result of one of these. It is a study of the food chain in China from the perspective of the individual consumer and the household.
The author has used an anthropological approach to her task. She attempted "to isolate and identify both traditional and contemporary political and socio-economic determinants of food intake and to document patterns of food supply and consumption." She has been successful. Her focus is on food supply and the food chain, rather than on the nutritional result. Her studies were done in two urban settings, in Shanghai and Beijing, and in two nearby rural areas. The findings are described in the context of the recent history of China's food economy as changes have followed shifts in the political climate.
Since the revolution, the underlying policy of the government has been to ensure a supply of grain staples in quantities sufficient to meet the nutritional requirements of each person. This has been accomplished through governmental purchase and distribution of staples produced primarily by collective farming, at times supplemented by grain purchases on the international market in addition, and to varying degrees, non-staples have entered a more or less free market. These are produced on land allotted to the commune for this purpose or on small plots assigned to individual families. Both in rural and urban China the state has assumed and operated a large part of the non-staple food market and taken responsibility for production, procurement and retailing at fixed prices, but in addition the state allows for limited free markets to operate because pragmatically this has encouraged productivity.
A fluctuating balance between state controls and free market has existed for the past 25 years. At present, market forces predominate in setting policy. One may argue at any length whether domestic sideline production represents retention of an element of capitalism, or is a dependency of socialism and accordingly non-capitalistic in nature, or is simply a practical adjunct to the socialist economy. It makes little difference; domestic sideline production makes a significant and elastic contribution to the family rice bowl. The important and most interesting question is whether in the long term a food system with tight state control that guarantees a "minimal rice bowl" can exist alongside or as part of a system that also provides for expanding production and an "expanding rice bowl." The answer so far would appear to be yes.
This book contains a wealth of information on the food-chain economics of China drawn not only from many other sources but also from the author's exhaustive analysis of the community and family settings in which she did her field research. Many charts and tables illustrate the workings of the food chain. While it might not be possible to generalize her observations in her four study sites to the rest of the country, they surely apply to a large fraction of China's one billion people, and perhaps to most of them. This monograph will serve as a valuable reference source to sinologists who are interested in the political-economic history of China and more broadly to those who work on the problems of development in the countries of the Third World.
John B. Stanbury
Professor Emeritus
Department of Nutrition and Food Science
Massachusetts Institute of Technology
Vegetables in the Tropics. By H. D. Tindall. Avi Publishing Company, Westport, Conn., USA,1984. 533 pp. US$37.50. (Available in North and South America from the publisher and booksellers; elsewhere from Macmillan Press, Ltd., Houndsmill, Basingstoke, Hampshire RG21 2XS, UK.)
This book provides concise information on the cultural and environmental requirements of about 140 vegetable crops grown in tropical regions. Information given for each crop includes: climatic and soil requirements, propagation and establishment, crop density, irrigation, and reference to any special treatments such as staking or pruning. The crop details are given under family headings since many crops of the same plant family frequently have similar cultural requirements.
Major pests and diseases that affect these crops are listed for each family in a comprehensive appendix. Brief details of yield, nutritional content, post-harvest handling, preparation for market, and storage are included for most crops, together with outlines of seed production techniques. A thorough list of references, a bibiliography to aid extended reading, and many photographs, charts, and drawings also support the text.
The book will serve well as a textbook and as a reference for extension service staff and researchers who work with tropical crops and seek to develop the potential for increased production.
Veterinary Pharmacology and Toxicology. Edited by Yves Ruckebusch, Pierre-Louis Toutain, and Gary D. Koritz. Avi Publishing Company, Westport, Conn., USA, 1984. 838 pp. US$56. (Available in North and South America from the publisher and booksellers; elsewhere from MTP Press Ltd., Falcon House, Cable St., Lancaster LA1 1RN, UK.)
This book updates research and points the direction for future work in veterinary pharmacology and toxicology. A compendium of work by over 150 international authorities, it is based on the proceedings of the Second European Association for Veterinary Pharmacology and Toxicology, conducted in Toulouse, France, in 1982. The subject matter covers many aspects of veterinary pharmacology, with special emphasis on ruminant pharmacology and animal models, as well as histamine, dopamine, and serotonin receptors.
The collection also examines in detail the effects of new drugs, and provides discussion on the assessment of carcinogenic properties of veterinary drugs, the clinical utility of pharmacokinetics, and a section on toxicology. This hardbound volume will be useful for pharmacologists, toxicologists, and animal scientists concerned with the development, use, and effects of drugs in veterinary medicine, including medicated feeds and anaesthesia.
Health, Culture, and Community. Edited by Benjamin D. Paul. Russell Sage Foundation, New York,1955 (reprinted 1981). 493 pp. Paperback, US$7.95.
When this book was first published in 1955, it immediately became a valuable resource for teaching the practice of nutrition and public health interventions at the village level. Some of the cases appear as successes, others as failures. They were selected to illuminate various facets of community process. They help to understand how human communities perceive and react to problems and to efforts from outside and inside to improve their health. The sixteen cases illustrate problems of over-population, social segmentation, health personnel, re-educating the community in reacting to crisis, and programmes that combine service with research. Although reprinted twelve times previously, this book was out of print for several years, but it is now available again.
Nutrition and Development. Edited by Z.L. Ostrowski. Proceedings of the First International Round Table Conference on Nutritional Status of Pregnant Women in the Sudan. ADE, European Association for Studies on Nutrition and Child Development, 9 Boulevard des Capucines, 75002 Paris, France, 1984. 215 pp. US$20. Summary in English, French, and Arabic.
This work presents a summary of the proceedings of a conference organized by the European Association for Studies on Nutrition and Child Development (ADE) and held in Paris 28 September to 2 October 1982. The principal theme of the conference was the nutritional status of children in the developing countries. The participants (specialists in paediatrics, nutrition, biochemistry, public health, biostatistics) discussed particularly the key aspects of health and nutritional care required to ameliorate the apparently unacceptable nutritional status of traditional populations. The work was based on the first results of a longitudinal study run by the ADE Research Centre on the population of South Sudan. This population is characterized by its lack of contact with contemporary civilization, and it will be subjected to extremely rapid changes in living conditions because of the construction of a significant artificial waterway, the Jonglei Canal.
The results of this study should provide information (risk factors, relation to food habits, elaboration of health statistics) that will allow the application of preventive health measures, determine several nutritional policies, and orient food and agronomic research.
Practising Health for All. Edited by David Morley, Jon Rohde, and Glen William. Oxford University Press, Oxford, New York, Toronto, 1983. 333 PP.
This book presents a wide range of case studies depicting typical problems that arise in the implementation of primary health care (PHC) programmes and suggests how these may be overcome. It emphasizes that an essential pre-condition to successful PHC programmes is a supportive political climate in which health is viewed as part of total human development and the right of every individual. It also documents that community participation implies not just the mobilization of community resources but greater control by the people over the social, political, economic, and environmental factors affecting their health. It requires PHC interventions that are technologically appropriate. Since current WHO/UNICEF and national strategies for nutrition improvement are integrated with PHC programmes, the case studies of this book and the lessons they teach should be familiar to all public health nutritionists.