                             VegSocUK Information Sheet
                              THE VEGETARIAN SOCIETY


   ___________________________________

                                     PULSES

   Peas, beans and lentils are known as pulses. They are the seeds of plants
   belonging to the family Leguminosae, which gets its name from the
   characteristic pod or legume that protects the seeds while they are forming
   and ripening. With approximately 13,000 species, the family Leguminosae is
   the second largest in the plant kingdom and it is very important
   economically. Different kinds of legumes provide us with food, medicines,
   oils, chemicals, timber, dyes and ornamental garden plants. Legume products
   include carob, senna, gum arabic, balsam, indigo and licorice. Pulses are
   valuable because they contain a higher percentage of protein than most other
   plant foods.

  ORIGINS

   Pulses have been used as food for thousands of years. The lentil was probably
   one of the first plants ever to be domesticated by humans. Most pulses prefer
   warm climates but there are varieties which grow in temperate regions. They
   can be eaten fresh or dried and come in a great number of varieties with a
   range of colours, flavours, and textures. Inspite of its common name, the
   peanut or groundnut is also a legume rather than a nut.

  NUTRITION

   All pulses, except for soya beans, are very similar in nutritional content.
   They are rich in protein, carbohydrate and fibre, and low in fat which is
   mostly of the unsaturated kind. They are also important sources of some B
   vitamins. Fresh pulses contain vitamin C, but this declines after harvesting
   and virtually all is lost from dried pulses. Canned pulses however, retain
   about half their vitamin C except for canned, processed peas which have been
   dried before canning. Canning doesn't affect the protein content, eliminates
   the need for soaking and considerably reduces the cooking time compared with
   dried pulses. Frozen peas will have also lost about a quarter of their
   vitamin C content.

   Pulses are usually eaten for their high protein content. A typical
   nutritional breakdown is that for haricot beans which are used to make baked
   beans, contain, per 100g dried beans 21.4g protein, 1.6g fat, 45.5g
   carbohydrate, 25.4g fibre, 6.7mg iron and 180mg calcium.

   The nutritional quality of the soya bean is superior to that of other pulses.
   It contains more protein and is also a good source of iron and calcium. The
   nutritional breakdown of soya is per 100g of dried beans 34.1g protein, 17.7g
   fat, 28.6g carbohydrate, 8.4mg iron and 226mg calcium. Dried soya beans are
   lengthy to prepare because they need at least 12 hours soaking and 4 hours
   cooking time, boiling for the first hour, but nowadays a large number of soya
   based foods including tofu, tempeh and texured vegetable protein (TVP) are
   available,

  STORAGE & COOKING

   One advantage of dried pulses is that they will store very well for long
   periods if kept in a dry, airtight container away from the light. However it
   is best to eat them as fresh as possible. Pulses toughen on storage and older
   ones will take longer to cook. Allow about 55g dried weight per person, once
   soaked and cooked they will at least double in weight. Most dried pulses need
   soaking for several hours before they can be cooked, exceptions are all
   lentils, green and yellow split peas, blackeye and mung beans. Soaking times
   vary from 4-12 hours, it is usually most convenient to soak pulses overnight.
   Always discard the soaking water, rinse and cook in fresh water without any
   salt, which toughens the skins and makes for longer cooking. Changing the
   water will help to reduce the flatulence some people suffer when eating
   pulses, also reputed to help is the addition of a pinch of aniseeds, caraway,
   dill or fennel seeds.

  TOXINS IN PULSES

   Consumers should be aware that it is not safe to eat raw or undercooked
   kidney and soya beans. There is no need to avoid them as long as they are
   thoroughly cooked.

    Red kidney beans

   Incidents of food poisoning have been reported associated with the
   consumption of raw or undercooked red kidney beans. Symptoms may develop
   after eating only four raw beans and include nausea, vomiting and abdominal
   pain followed by diarrhoea. A naturally occurring haemaglutin is responsible
   for the illness, but can be destroyed by high temperature cooking, making the
   beans completely safe to eat. For this reason, kidney beans must not be
   sprouted. Kidney beans should be soaked for at least 8 hours in enough cold
   water to keep them covered. After soaking, drain and rinse the beans,
   discarding the soaking water. Put them into a pan with cold water to cover
   and bring to the boil. The beans must now boil for 10 minutes to destroy the
   toxin. After this the beans should be simmered until cooked (approximately
   45-60 minutes) and they should have an even creamy texture throughout - if
   the centre is still hard and white, they require longer cooking.

    Soya beans

   Contain an anti-trypsin factor (or trypsin inhibitor) which prevents the
   assimilation of the amino acid methionine. Soya beans also require careful
   cooking to ensure destruction of this factor. They should be soaked for at
   least 12 hours, drained and rinsed then covered with fresh water and brought
   to the boil. Soya beans should be boiled for the first hour of cooking. They
   can then be simmered for the remaining 2-3 hours that it takes to cook them.
   Soya flour should state heat treated on its packaging. Other soya products
   (eg tofu, tempeh, soya milk, soya sauces and miso) are quite safe to use.
   Soya beans can be sprouted, but the sprouts should be quickly blanched in
   boiling water to inactivate the trypsin inhibitor.

    Pressure cooking

   The temperatures achieved in pressure cooking are adequate to destroy both
   haemaglutins and the trypsin inhibitor. Pressure cooking also considerably
   reduces cooking times - kidney beans 10-20 minutes, soya beans 1 hour.

    Canning

   The temperature achieved in the canning process also renders pulses quite
   safe.

    Slow cookers

   Pulses must be soaked and boiled for 10 minutes before being added to a slow
   cooker, as they do not reach sufficiently high temperatures to destroy the
   toxins.

   As beans and peas are all very similar nutritionally, with the exception of
   soya, they can be interchanged in most recipes if you want to experiment or
   have run out of one kind, as long as you take into account the different
   cooking times. If the beans are likely to need a lot longer to cook than the
   other ingredients, try pre-cooking them in a separate pan before adding to
   the other ingredients or using canned beans.

  SPROUTING

   Many whole pulses (eg aduki, chickpeas, whole lentils, marrowfat peas, mung
   and soya beans) can be sprouted which increases their nutritional value.

  FURTHER INFORMATION

   The Bean Information Bureau
   c/o Paragon Communications, 142 Wardour Street, London, W1V 3AU.
   ___________________________________


//
This article is copyright to the Vegetarian Society (UK), but may be freely
copied for non-commercial use provided it is kept intact, not altered
and these lines are included.

For futher information contact: The Vegetarian Society, Parkdale, Dunham Road,
Altrincham, Cheshire WA14 4QG, England. Tel: (England) 061 928 0793
email: vegsoc@vegsoc.demon.co.uk
//



[The text of this file was obtained from the Vegetarian Society (UK) in
March 1995.]

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