African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6863

Full Length Research Paper

In-vitro bioavailability of selected minerals in dry and green shelled beans

Peter Mamiro
  • Peter Mamiro
  • Department of Food Science and Technology, Sokoine University of Agriculture, P. O. Box 3006, Morogoro.
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Akwilina Mwanri
  • Akwilina Mwanri
  • Department of Food Science and Technology, Sokoine University of Agriculture, P. O. Box 3006, Morogoro.
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Delphina Mamiro
  • Delphina Mamiro
  • Department of Crop Science and Production, Sokoine University of Agriculture, P. O. Box 3005, Morogoro, Tanzania.
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Martha Nyagaya
  • Martha Nyagaya
  • The Children's Investment Fund Foundation (UK), 3rd floor, ABC Place, Waiyaki Way, PO Box 1694-00606, Nairobi, Kenya.
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Julius Ntwenya
  • Julius Ntwenya
  • School of Nursing and Public Health, Department of Public Health, College of Health Sciences University of Dodoma, P. O. Box 259 Dodoma, Tanzania.
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  •  Received: 01 April 2012
  •  Accepted: 12 August 2015
  •  Published: 03 March 2016


Mineral deficiency especially that of iron and zinc has continuously emerged as  a public health issue in developing countries, probably due to the over dependence on plant food sources, which contain more than enough minerals to meet the daily requirement but have a low bioavailability for physiological purposes. Experiments on in-vitro bioavailability were carried out on dry and green shelled beans. In-vitro bioavailability of iron and zinc in bean samples was determined by HCl-pepsin (HCl-P) and pepsin-pancreatin (P-P) method. The amount of the proxy bioavailable minerals were obtained by atomic absorption spectrophotometry. In both minerals there was a small but significant (P=0.009) and (P=0.0003) increase in in-vitro bioavailability after cooking. The average increase for all the varieties was 3.2 to 3.4% for iron and 1.3 to 1.6% for zinc. The two minerals were more available in cooked green shelled beans compared to dry ones. The highest difference for iron bioavailability was observed in Maharagi soja (12.9%) while lowest was in TY 3396-12 (1.4%). The highest observed for zinc was 3% in G59/1-2. Vulnerable groups who suffer from iron and zinc deficiency should be encouraged to consume green shelled beans more often in comparison to dry beans to improve their mineral uptake.


Key words: In-vitro bioavailability, green, shelled, dry beans, minerals.