Lucerne As Source Of Human Food

Press, Volume CVIII, Issue 31760, 17 August 1968, Page 9

Lucerne As Source Of Human Food

It was to plants that the world population of the future must look for its requirements of protein, Dr R. M. Allison, a scientist of the Plant Chemistry Division of the Department of Scientific and Industrial Research at Lincoln, told the annual conference of the New Zealand Dietetic Association in Christchurch, this week.

Dr Allison emphasised the possible role of lucerne in filling this need and referred to investigations being made in New Zealand into extraction of protein from plant sources.

In discussing the protein gap in the world, he said that the world population could he split Into three categories—the 1000 m well fed people in the western world with adequate supplies of high class animal protein, the 2000 m cereal eaters in areas like Central and South Africa, South America and India whose diets were generally inadequate In quality and a few hundred millions (200 m to 400 m) who ate starchy roots and fruits, low in protein, and did not get enough protein, let alone adequate quality protein. It was up to the 1000 m well fed to see that this imbalance in the diet of the rest of the population did not continue, but it was a characteristic of the former group that they ensured that it did continue.

He referred to the ironical situation where surplus dried milk that had been available for distribution through U.N.I.C.E.F. was now being fed to vealers, and shrimps and prawns were being shipped from protein-starved countries, India and Pakistan, to the United States and Western Europe. New Zealand was at the top of the list as far as protein intake, and the animal component of this intake, was concerned. Dr Allison said, and he hoped that New Zealand would not also be guilty of drawing much needed supplies of protein from other areas of the world. At the level of protein consumption in New Zealand--105 grams a person a day— Dr Allison said he wondered whether New Zealanders might not be heirs to some metabolic disorders, such as kidney disturbances, that might be as great as if they were suffering from starvation.

While utilisation of the whole of the 840 m bushel United States soya bean crop, most of which was being used as stock feed, could solve the present world protein shortage, Dr

Allison said that to meet future demands the use of unconventional foods would be necessary. In the next 32 years, he said, the population of the world would increase from 3500 m to 7000 m. But in the last 32 years agriculture had made relatively little progress.

As sources of protein, he said that cattle for beef production, pigs for pig meat and poultry for meat and eggs were inefficient converters of food to protein—none of these were better than 25 per cent efficient What shareholders would support a commercial undertaking that was so inefficient? he asked.

“I do not think we can really afford to proceed along these lines to increase protein production,” he said. “1 maintain that we should not try. Any improvement obtained in this direction would only be a drop in the ocean of requirement.” There was a need for a crash programme to meet the world’s protein requirements and the need was to improve the intake of nlant protein. There would, of course, he said, always be some animals which would be run on those areas that could not be tilled, and to eat offals.

If sources of animal protein were disregarded, Dr Allison said that the sources remaining were plant and microbial and the size of a fermentation industry to meet the needs with microbial protein would have to be colossal. The alternative was, therefore, plants and it would be necessary to see what could be done to improve both the quantity and quality of plant protein sources. On the basis of American data. Dr Allison said, no grain or seed crops could compare with lucerne as a source of protein on a per acre level. This showed that a little more than a ton of crude protein would be available from 5.4 tons of lucerne. Dr Allison discussed work being done to improve grain crops as sources of protein, but he emphasised the slowness of the impact of this sort of work. From the time that a discovery was made by a plant breeder until it had a practical impact, he said could be as much as 20 years. But, he said, it was hoped that in the next 10 years there would be a revolution in the kinds of wheat and maize grown In those areas of the world that depended on cereals for protein.

Dr Allison said that it had only been in 1964 that the discovery had been made that a gene, Opaque 2, could be responsible for considerable improvement in important amino acid levels in maize. Considerable work had followed this discovery and only now was there enough seed to enable areas to be planted in this sort of maize.

In wheat it had been found that in selecting for leaf rust resistance selection was also automatically being done for high protein. A plant breeding station in the United States had found that a very strongly leaf rust resistant variety. Atlas 66, had a protein content of up to 24 per cent, which was about double that of normal wheat. The incorporation of the gene for this factor into commercially grown varieties could be part of the answer to providing more protein. The gene for leaf rust resistance also affected the quality of the protein. He quoted figures to show how use of this material in crossing had resulted in higher amino acid levels. In the same way, Dr Allison said that it was almost

certain that rice varieties high in protein and in protein quality would be found. Dr Allison said that there was also a place for upgrading for human consumption meals like those made from soya beans, safflower, linseed and cotton seed, which had been used for a long time for animal feeds. They were also valuable sources of protein. There were problems in using legume sources for protein, but industry had dealt with similar problems in other fields and he could see no reason why these should not be solved too, provided there was a will to do it and a little persistence. The favoured source of plant protein was lucerne, it produced a large amount of protein. It was a perennial lasting some five or 10 years. It was deep rooting and could be irrigated and it had a tremendous potential production. He was sure that Dr K. F. O’Connor, of the Grasslands Division of the Department of Scientific and Industrial Research at Lincoln, would support him in saying that yields of up to 20,000 to 30,000 lb of dry matter to the acre were possible. Lucerne contained about 20 per cent protein so If they were successful in extracting only half there would be a considerable amount of protein—at least a ton to the acre.

Dr Allison said that one of the reasons why man had chosen herbivorous animals to accompany him in his later evolution was that they had the facility to break open the paper bag surrounding the plant cell and release the protein.

All plant cells had a cellulose bag around them, so in protein extraction the cel) walls had to be broken and removed either by filtering or centrifuging. The protein had then to be separated out of the juices. This was done by heat coagulation or coagulation with acid. The coagulant had to be separated from the non-protein component. The protein then had to be dried and the by-product, which still contained 10 per cent protein, could be fed bark to animals, possibly to stall-fed beasts, through a silage, which if necessary could be supplemented with urea. A major problem would be persuading people to eat this product, which would have a green grass flavour. But it might be added to milk, sauces and gravies. In countries like India, where curries were widely eaten, he said that this would be an ideal food to use it in.

Dr Allison shoved slides of a machine developed for the extraction of plant protein at 'Rothamsted in Britain.

In New Zealand, Dr Allison said, the Minister of Science, Mr Taiboys, in opening the new laboratories of the Dairy Research Institute last year, had been tempted to cogitate as to what happened to the protein that this country produced. He had realised that New Zealand was an exporter of proteinin fact the only export product that did not contain protein was butter. He had set up a committee to look into the efficiency of the country's protein export industry. This investigation had found that many of this country's primary industries were notoriously inefficient as conservers of protein. On paper the most productive protein industry would be that based on leaf protein, which was not currently a direct export industry. A committee of the Depart ment of Scientific and Industrial Research had followed this up with the idea of using leaf protein for feeding the peoples of the world. The New Zealand Agricultural Engineering Institute at Lincoln had promised to make a machine for extraction of protein so that various crops could be evaluated. At question time, Dr Allison said that in Chad, a bluegreen nitrogen-fixing algae, growing in Lake Chad, contained 60 to 70 per cent of protein. It had only to be raked out of the lake and dried in the sun before being used. The Aztecs had used it, he recalled.