BIOCHEMICAL EVALUATION OF RAW AND PROCESSED KIDNEY BEAN (Phaseolus vulgaris L.) SEEDS FOR MONOGASTRIC ANIMAL FEED PRODUCTION

Authors

  • Damang, P. J. Plateau State College of Agriculture, Garkawa
  •  Tuleun, C. D.
  • Oluremi, O. I. A.
  • Carew, S. N.  

Keywords:

kidney beans, processing, anti-nutritional factors

Abstract

The red variety of kidney beans was subjected to various methods of processing to determine the processing method that was most effective in destroying the anti-nutritional factors while preserving the nutrient content of the seeds. The processing methods were sun-drying (raw seeds), boiling, toasting, boiling/fermenting and sprouting. The five processing methods were replicated three times in a completely randomized design. The anti-nutritional factors investigated were trypsin inhibitor, hydrocyanic acid (HCN), tannins, phytic acid, oxalate and haemagglutinins. The effects of processing method on the proximate composition and profile of amino acids were also investigated. The results showed that fermented seeds had significantly (P<0.01) higher crude protein content than boiled seeds, which had a higher (P<0.01) value than toasted and sprouted seeds. Boiled and fermented kidney beans had similar contents of ether extract which were significantly (P<0.05) higher than those of other processing methods. Methionine and tryptophan were present in minute amounts in the raw and processed kidney beans. With the exception of isoleucine and phenylalanine, all the essential amino acids of the raw and processed kidney beans did not differ (P>0.05) significantly. Fermented kidney bean seeds had the highest percent destruction of trypsin inhibitor of 97.42, followed by boiling, sprouting and toasting whose values were 94.85, 89.69 and 88.92, respectively. The per cent destruction of HCN was 71.30, 67.48 81.45 and 58.40 for boiled, toasted, fermented and sprouted kidney beans, respectively, and that of tannin was 80.84, 39.62, 82.58 and 84.91 respectively. Each processing method significantly (P<0.01) reduced all the anti-nutritional factors relative to the raw seeds. Boiling, toasting or fermentation is recommended for processing kidney beans for use in the diets of monogastric animals.

Published

2017-06-30