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Common vetch Vicia sativa ssp. sativa cv. Blanchefleur, a mimic of red lentils

D. Enneking, Ph.D.

Centre for Legumes in Mediterranean Agriculture, University of Western Australia, Nedlands WA 6907

Current Address: Weuert 15a D-49439 Steinfeld, Germany
 

Common vetch in Australia


Due of its diverse utilisation options, common vetch (V. sativa ssp. sativa) has gained popularity as a crop in Australia. It can be grown for fodder, hay, green manure or seed production. As a legume it fits well into cereal rotations, provides nitrogen to the soil, and if properly managed can reduce the incidence of diseases in succeeding crops.

Australian farmers, especially in South Australia and Victora, have been able to increase the profitability of their farming operations through the inclusion of common vetch into their rotations. Excellent hay crops can be produced if vetch is sown together with oats. Good seed yields can also be obtained from common vetch crops.

The cultivar "Languedoc" is very well adapted to dryland farming conditions and seed yields of up to 2t/ha have been achieved in a short gowing season 400mm/annum environment.

The cultivar "Blanchefleur" is later flowering and requires more moisture for optimum seed production. The seeds of this cultivar have red cotyledons. When the seed is split it resembles that of red lentils.

For further details on production aspects see AgWA Factsheet "Growing vetches in Western Australia" or the vetch production bulletin (updated 2003) for Western Australia. Current information can also be found in the annual crop variety sowing guides for WA.

Vetch seeds are high in protein (28-32%) and are a quality feed for ruminant animals such as sheep and cattle, however, their use as a human food is questionable because of their known toxicity to monogastric animals such as rats and poultry.

Rats show reduced growth. Poultry fed a diet containing 50% common vetch have high mortality rates. Up to 10% vetch may be included in diets fed to pigs without noticeable production losses. We do not have any information about the effects of common vetch on human health, however, the available scientific evidence from experimental studies with monogastric animals suggests that humans health can also be affected by the consumption of this grain (see below).

This picture shows the similarity between split red lentils (Lens culinaris Med.) [ at the top] and the split seeds of the Vicia sativa cultivar Blanchefleur. The petri dish on the left hand shows the unoiled split seed. To the right you can see the same product coated with vegetable oil.

Reference: Tate, M. E. and Enneking, D. (1992) A mess of red pottage. Nature 359, 357-358

A simple test back to top

The split seeds of Blanchefleur vetch can be easily distinguished from red lentils with the use of Thin Layer Chromatography (TLC). A reference sample of vetch is required for this test and can be obtained from Dr. Max. E. Tate, Dep. Plant Science, University of Adelaide, Waite Campus, Glen Osmond SA 5064, South Australia, Fax: 08-8303 7109 mtate@waite.adelaide.edu.au

Toxicity back to top

The split seeds of Blanchefleur vetch contain ca. 1% of the toxin gamma-glutamyl-beta-cyanoalanine. This toxin affects sulfur amino acid metabolism, specifically, the conversion of methionine to cysteine, which leads to an increased excretion of cystathionine, the intermediate in this biochemical pathway, in urine.

The toxin does also get incorporated into gamma-glutamyl-beta-cyanoalanine-glycine which has been found in brain tissue of experimental animals fed with diets containing Blanchefleur vetch. This compound is a structural analogue of glutathione.

Glutathione is important for a diverse range of biochemical functions and interference with its metabolism can have grave health consequences. For example, a range of environmental toxins is detoxified by glutathione, so depletion of this protecting agent can lead to an increased susceptibility and hence higher intoxication frequencies.

There is serious concern that humans may be affected by the consumption of vetch, especially if their nutritional intake of sulphur amino acids, particularly cysteine, is low,  since then heir requirements for cysteine need to be derived from methionine. This pathway is inhibited by beta-cyanolanine.  In addition, vetch seeds contain a toxin (vicine) which can provoke favism, a genetically linked hemolytic disease, usually caused by the consumption of faba beans (Vicia faba). Favism is prevented by food taboo, however, if vetch is not labelled appropriately, it cannot be identified as a potential threat by individuals who are susceptible to this disease.
 
 

Detoxificationback to top

The toxicity of common vetch grain can be reduced by leaching. Food acids may also be used to inactivate the toxin gamma-glutamyl-beta-cyanoalanine. Red lentils are not leached, so vetch substituted for red lentils is not leached either, unless the consumer is informed about the necessity to do so.

Vetches Feed or Food?back to top

Vetches: Feed or Food? Tate, ME (1996)  Chemistry in Australia 63, 549-550
 


Chronology of Events September 1998-  back to top

Customs seize six container loads of animal feed to be sold as Mysore Dhal The Daily News, Sri Lanka 15.9.98
[ link no longer exists (Jan 2005)]

Customs directed to re-ship sealed consignment The Daily News, Sri Lanka 7.10.98
[ link no longer exists (Jan 2005)]

Lankan Customs seek Aussie help to probe Intl. contaminated food racket The Daily News, Sri Lanka 8.10.98
[ link no longer exists (Jan 2005)]

Australian High Commission on imports of vetch The Daily News, Sri Lanka 10.10.98
[ link no longer exists (Jan 2005)]
 

Covert trade in toxic vetch continues  Nature 400 (6742):207 (1999)
 

Business recorder, Pakistan: Government urged to confiscate vetch 8.12.1999
[ link no longer exists (Jan 2005)]

Business recorder, Pakistan: Australian vetch is safe to eat: acting High Commissioner 2.12.1999
[ link no longer exists (Jan 2005)]

Business recorder, Pakistan: Masoor importers may be penalised 13.11.1999
[ link no longer exists (Jan 2005)]

Business recorder, Pakistan: Government bans vetch import from Australia for health reasons 11.11.1999
[ link no longer exists (Jan 2005)]

Current issues Lentils and Vetch (Pulse Australia link) 21.10.1999
[ link no longer exists (June 2001)]

The Independent, Dhaka, Bangladesh: Vetch exports to Bangladesh safe, claims Australian pulses industry 20.10.1999
[ link no longer exists (June 2001)]

The Independent, Dhaka, Bangladesh: Customs suspends clearance of vetch 19.10.1999

Pulse Australia Press Release: Substitution of lentils with vetch - substitution is the problem, not the vetch. [ link no longer exists (June 2001)]
 

BBC News: Food scandal in Bangladesh 17.10.1999 Published at 15:44 GMT 16:44
[ link no longer exists (June 2001)]

BBC News: Bangladesh bans poison feed 17.10.1999 Published at 16:40 GMT 17:40 UK

Reuters: Bangladesh bans import of vetch on health grounds 17.10.1999
[ link no longer exists (June 2001)]

The Independent, Dhaka: Complete ban on Australian toxic' lentil import demanded 17.10.1999
[ link no longer exists (June 2001)]

ABC SA country hour: Australian Vetch Prices Drop 1.2.2000
[ link no longer exists (Jan 2005)]

Commonwealth of Australia- Official Committee Hansard- Joint Standing Committee on Foreign Affairs, Defence and Trade -Australia's relations with the Middle East (PDF file, 461 K) 14.9.2000

Business Recorder, Lahore, Pakistan, Marketing of vetch restricted 27.10.2000
[ link no longer exists (Jan 2005)]


Breeding a low toxin vetch cultivar back to top

University of Adelaide-Media release   New grain variety opens up possibilities for Australian farmers  30.1.2001
[ link no longer exists (Jan 2005)]

D. Chowdhury, M. E. Tate, G. K. McDonald and R. Hughes.
Progress Towards Reducing Seed Toxin Levels in Common Vetch (Vicia sativa L.)
Proceedings of the 10th Australian Agronomy Conference, Hobart, 2001 1.2.2001

Contacts:
Prof. Max Tate, Adelaide, Australia
Dr. Doza Chowdhury, Narrabri, Australia
Dr Dirk Enneking email: enneking (at) cyllene.uwa.edu.au


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Last update 14.09.2006

 The test  Toxicity    Feed or Food?  Chronology of Events Development of low toxin vetch cultivars

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