Plant Foods for Human Nutrition

, Volume 40, Issue 4, pp 249–258 | Cite as

Changes in some antinutrients of cowpeas (Vigna unguiculata) processed with ‘kanwa’ alkaline salt

  • Stella G. Uzogara
  • Ian D. Morton
  • John W. Daniel


The effect on several anti-nutritional factors in cowpeas (Vigna unguiculata L. Walp) was investigated following treatment at 100°C or 121°C with solutions (0.1% w/v) of kanwa rock salt or NaHCO3 in distilled water. The concentration of polyphenols, calculated as tannic acid, was reduced substantially up to 67% under the alkaline conditions employed, but the reduction appeared to be greater (69–79%) at higher temperature. The loss of phytic acid was greater (27–40%) when beans were cooked in NaHCO3 than in kanwa (11–29%). The concentration of reducing sugars was decreased in all treatment groups especially under alkaline conditions. There was no evidence for the formation of lysinoalanine in any of the samples.

Key words

cowpeas antinutrients kanwa processing 


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Copyright information

© Kluwer Academic Publishers 1990

Authors and Affiliations

  • Stella G. Uzogara
    • 1
  • Ian D. Morton
    • 1
  • John W. Daniel
    • 1
  1. 1.Department of Food and Nutritional Sciences, Food Science DivisionKing's College, LondonLondonUK

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