European Journal of Nutrition

, Volume 52, Issue 2, pp 583–589 | Cite as

Sun-dried cowpeas and amaranth leaves recipe improves β-carotene and retinol levels in serum and hemoglobin concentration among preschool children

  • Mildred P. Nawiri
  • Hudson NyambakaEmail author
  • Jane I. Murungi
Original Contribution



Vitamin A deficiency (VAD) and anemia are major challenges among children and expecting and lactating mothers in developing countries. Intervention with locally available dark green leafy vegetables (DGLV) is more sustainable to eradicate VAD, being cost-effective and readily adaptable to local communities. DGLV contain high levels of iron and β-carotene (BC) and therefore useful in fighting VAD and anemia. Since DGLVs are season-dependent sun-drying enables their availability during low seasons. However, their contribution to the bioavailability of BC and the improvement of hemoglobin are not well understood. The study therefore investigated the effect of consuming cooked recipe consisting of sun-dried amaranth and cowpea leaves on the levels of BC, retinol, and hemoglobin in preschool children from Machakos District, a semiarid region in Kenya.


Vegetables were purchased from local vegetable market, with some sun-dried in an open shade. Levels of BC and retinol in serum and BC in fresh and processed vegetables were determined by a HPLC method and hemoglobin using a portable Hemocue Analyzer.


All-trans-BC levels in uncooked fresh cowpea and amaranth leaves were 806.0 μg/g and 599.0 μg/g dry matter, respectively, while the dehydration and cooking processes retained the β-carotene levels at over 60 %. Consumption of the dehydrated vegetables significantly improved both serum BC and retinol levels (p < 0.05), while the baseline hemoglobin levels improved by 4.6 %.


The study has shown that intervention with locally available sun-dried vegetables improves the bioavailability of BC, retinol, and hemoglobin levels among preschool children.


β-carotene Retinol Hemoglobin Vitamin A deficiency Sun-dried vegetables 



The authors wish to acknowledge DAAD Germany Academic Exchange Service for full sponsorship, Kenyatta University Deans Research Grant, International Plant Genetic Resource Institute (IPGRI), and Sigma-Xi for partial financial support; Kenya Medical Research Institute (KEMRI) for serum sample storage, Department of Nutritional Science and Technology, Jomo Kenyatta University of Agriculture and Technology (JKUAT) and Department of Chemistry, University of Siegen, Germany for attachment and HPLC method development.

Conflict of interest

The financial relationship with the organizations only assisted in enabling carrying of the study and apart from acknowledging the assistance the authors declare that there is no conflict of interest.


  1. 1.
    Caulfield LE, de Onis M, Blossner M et al (2004) Under nutrition as an underlying cause of child deaths associated with diarrhea, pneumonia, malaria, and measles. Am J Clin Nutr 80(1):193–198Google Scholar
  2. 2.
    Olson JA (1999) Carotenoids. In: Shils ME, Olson JA, Shike M, Ross AC (eds) Modern nutrition in health and disease, 9th edn. Williams and Wilkins, Phhiladelphia, PA, pp 525–541Google Scholar
  3. 3.
    UNHCR/WFP (2011) Guidelines for selective feeding: the management of malnutrition in emergencies. UNHCR Public Health and HIV Section, Geneva, Switzerland.
  4. 4.
    Anyango G et al (1989) Drought vulnerability in Central and Eastern Kenya. In: Downing TE (ed) Coping with drought in Kenya: national and local strategies. Lynne Rienner, Boulder, CO, pp 169–210Google Scholar
  5. 5.
    Oiye SO, Shiundu KM, Oniang’o RK (2009) The contribution of African vegetables to vitamin A intake and the influence of income in Rural Kenya. AfrJ Food Agric Nutr Dev 9:1–6Google Scholar
  6. 6.
    Beaton GH, Martorrel R, Aronsen KJ et al (1993) Effectiveness of vitamin A supplementation in the control of young child morbidity and mortality in developing countries-nutrition policy discussion paper No 13. University of Toronto, Ontario: International Nutrition ProgramGoogle Scholar
  7. 7.
    van Kappel AL, Steghens JP, Zeleniuch-Jacquotte A et al (2001) Serum carotenoids as biomarkers of fruit and vegetable consumption in the New York women’s health study. Public Health Nutr 4(3):829–835CrossRefGoogle Scholar
  8. 8.
    Drewnowski A, Rock CL, Henderson SA et al (1997) Serum beta-carotene and vitamin C as biomarkers of vegetable and fruit intakes in a community-based sample of French adults. Am J Clin Nutr 65(6):1796–1802Google Scholar
  9. 9.
    Nyambaka H, Ryley J (2001) Degradation pro-vitamin A active compounds of all-trans-β-carotene in dehydrated dark-green leafy vegetables. Bull Chem Soc Ethiop 15(1):57–64Google Scholar
  10. 10.
    Woods JL (1990) Moisture loss from fruits and vegetables. Postharvest News Inf 1:195–199Google Scholar
  11. 11.
    Eskin NAM (ed) (1989) Quality and preservation of vegetables. CRC Press, Boca Raton, FL, p 313Google Scholar
  12. 12.
    Arscott SA, Simon PW, Tanumihardjo SA (2010) Anthocyanins in purple-orange carrots (Daucus carota L.) do not influence the bioavailability of beta-carotene in young women. J Agric Food Chem 10 58(5):2877–2881Google Scholar
  13. 13.
    Tang G, Gu F, Hu SM et al (1999) Green and yellow vegetables can maintain body stores of vitamin A in Chinese children. Am J Clin Nutr 70:1069–1076Google Scholar
  14. 14.
    de Pee S, West CE, Permaesih D et al (1998) Orange fruit is more effective than dark-green, leafy vegetables in increasing serum concentration of retinol and B-carotene in schoolchildren in Indonesia. Am J Clin Nutr 68:1058–1067Google Scholar
  15. 15.
    Dauchet L, Péneau S, Bertrais S et al (2008) Relationships between different types of fruit and vegetable consumption and serum concentrations of antioxidant vitamins. Br J Nutr 100(3):633–641CrossRefGoogle Scholar
  16. 16.
    Fleshman MK, Lester GE, Riedl KM et al (2011) Carotene and novel apocarotenoid concentrations in orange-fleshed Cucumis melo melons: determinations of β-carotene bioaccessibility and bioavailability. J Agric Food Chem (Epub ahead of print)Google Scholar
  17. 17.
    Burri BJ, Chang JS, Neidlinger TR (2011) β-cryptoxanthin- and α-carotene-rich foods have greater apparent bioavailability than β-carotene-rich foods in Western diets. Br J Nutr 105(2):212–219CrossRefGoogle Scholar
  18. 18.
    Mulokozi G, Svanberg U (2003) Effect of traditional open sun-drying and solar cabinet drying on carotene content and vitamin A activity of green leafy vegetables. Plant Foods Hum Nutr 58:1–15CrossRefGoogle Scholar
  19. 19.
    Mulokozi G, Hedren E, Svanberg U (2004) In vitro accessibility and intake of beta-carotene from cooked green leafy vegetables and their estimated contribution to vitamin A requirements. Plant Foods Hum Nutr 59(1):1–9CrossRefGoogle Scholar
  20. 20.
    Tanumihardjo SA, Permaesih MD (2004) Vitamin A status and haemoglobin concentrations are improved in indonesian children with vitamin A and deworming interventions. Eur J Clin Nutr 58:1223–1230CrossRefGoogle Scholar
  21. 21.
    Combs GF Jr (1992) The vitamins: fundamental aspects in nutrition and health. Academic Press, San DiegoGoogle Scholar
  22. 22.
    Kanasawud P, Crouzet JC (1990) Mechanism of formation of volatile compounds by thermal degradation of carotenoids in aqueous medium. B-carotene degradation. J Agric Food Chem 38:237–243CrossRefGoogle Scholar
  23. 23.
    Rodriguez-Amaya DB (1993) Stability of carotenoids during the storage of foods. In: Charalambous F (ed) Shelf life studies of foods and beverages chemical, biological, physical and nutritional aspects. Elsevier Science, Amsterdam, pp 591–624Google Scholar
  24. 24.
    Khachik F, Goli MB, Beecher GR et al (1992) Effect of food preparation and qualitative and quantitative distribution of major carotenoid constituents of tomatoes and several green vegetables. J Agric Food Chem 40:390–398CrossRefGoogle Scholar
  25. 25.
    Nyambaka H, Ryley J (1995) An isocratic reversed-phase HPLC separation of stereoisomers of the provitamin A carotenoids (a and B-carotene) in dark—green leafy vegetables. J Food Chem 55:63–72CrossRefGoogle Scholar
  26. 26.
    Kostic D, White WS, Olson JA (1995) Intestinal absorption, serum clearance, and interactions between lutein and B-carotene when administered to human adults in separate or combined oral doses. Am J Clin Nutr 62:604–610Google Scholar
  27. 27.
    Castenmiller JJM, West CE (1998) Bioavailability and bioconversion of carotenoids. Ann Rev Nutr 18:19–38CrossRefGoogle Scholar
  28. 28.
    Castenmiller JJM, West CE, Linssen JH et al (1999) The food matrix of spinach is a limiting factor in determining the bioavailability of β-carotene and to a lesser extent of lutein in humans. J Nutr 129:349–355Google Scholar
  29. 29.
    Van het Hof KH, Brouwer IA, West CE et al (1999) Bioavailability of lutein from vegetables is 5 times higher than that of B-carotene. Am J Clin Nutr 70(2):261–268Google Scholar
  30. 30.
    Boileau AC, Merchen NR, Wasson K et al (1999) Cis-lycopene is more bioavailable than trans-lycopene in vitro and in vivo and in vivo in lymph cannulated ferrets. J Nutr 129:1176–1181Google Scholar
  31. 31.
    Erdman JW, Bierer TL, Gugger ET (1993) Absorption and transport of carotenoids. Ann NY Acad Sci 691:76–85CrossRefGoogle Scholar
  32. 32.
    Olmedilla B, Granado F, Blanco I et al (1994) Seasonal and sex-related variations in six serum carotenoids, retinol, and a-tocopherol. Am J Clin Nutr 60:106–110Google Scholar
  33. 33.
    Roodenburg AJC, Leenan R, van het Hof KH et al (2000) Amount of fat in the diet affects bioavailability of lutein esters but not of carotene, B-carotene, and vitamin E in humans. Am J Clin Nutr 71:1187–1193Google Scholar
  34. 34.
    Takyi EEK (1999) Children’s consumption of dark green, leafy vegetables with added fat enhances serum retinol. J Nutr 129:1549–1554Google Scholar
  35. 35.
    Tang G (1998) Green and yellow vegetables in maintaining stores of vitamin A in Chinese children. Am J Clin Nutr 68:1058–1067Google Scholar
  36. 36.
    Bulux J, Quan de Serrano J, Giuliano A et al (1994) Plasma response of children to short-term chronic B-carotene supplementation. Am J Clin Nut 59:1369–1375Google Scholar
  37. 37.
    Vuong LT, Dueker SR, Murphy SP (2002) Plasma beta-carotene and retinol concentrations of children increase after 30-d supplementation with the fruit Momordica cochinchinensis (gac). Am J Clin Nutr 75:872–879Google Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Mildred P. Nawiri
    • 1
  • Hudson Nyambaka
    • 1
    Email author
  • Jane I. Murungi
    • 1
  1. 1.Chemistry DepartmentKenyatta UniversityNairobiKenya

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