• May, Wed, 2024

Effect of Some Processing Methods on Nutrient Content and Anti-Nutritional Factors ofa Variety of Dolichos Lablab (Lablab Purpureus L.) Beans Grown in Kenya

*Sheila M. Kilonzi 1, 2, Anselimo O. Makokha,2 Glaston M. Kenji 2

1Department of Food Science and Nutrition, School of Agriculture and Biotechnology, Karatina University,

P.O. Box 1957- 10101, Karatina, Kenya

2Department of Food Science and Technology, Faculty of Agriculture, Jomo Kenyatta University of Agricul-
ture and Technology, P.O. Box 62000- 00200, Nairobi, Kenya ,

*Corresponding author: Sheila M. Kilonzi:

This study aimed to determine the effect of different processing methods on the proximate composition and anti-nutritional factors of Dolichos lablab beans (Lablab purpureus) of Kenya. The seeds of KAT/DL-2 variety,sourced from Kenya Agricultural Livestock and Research
Organisation, Katumani Dryland Research Station were sorted, then subjected to different
processing methods (soaking, cooking and germination). The samples were analysed for proximate
composition, tannins, phytates and trypsin inhibitory activity. The results showed a significant
increase (2.0%) in crude protein content for germinated lablab beans while carbohydrates content
was high in cooked samples. The variety KAT/DL-2 had high levels of phytates; 723.6 mg/100g
and tannins 330.3mg/100g and trypsin inhibitor activity 1.3mg/100g. Cooking achieved the highest
reduction of anti-nutrients with 88% reduction in TIU. The results revealed that the anti-nutrients
in lablab beans can be reduced using different methods of processing. However, there is need to
investigate the effect of combined methods on the nutrients and anti-nutrients.

KEY WORDS: Dolichos lablab, proximate composition, processing, anti-nutrients

  • May, Mon, 2024

Quantitative Changes of Ascorbic acid and Beta carotene in African nightshade (Solanum nigrum) and Spider plant (Cleome gynandra) due to traditional cooking methods used in western Kenya

*Anne A. Musotsi1 , Anselimo Makokha2 , Mary O. Abukutsa-Onyango3, and Sheila M. Kilonzi4

1-Masinde Muliro University of Science and Technology, P.O Box 190-50100, Kakamega-Kenya; E-mail:

2-Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000-00200, City Square, Nairobi; E-mail:

3-Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000-00200, City Square, Nairobi; E-mail:

4-Karatina University, P.O Box 1957-10101, Karatina; E-mail:

African nightshade (Solanum nigrum) and Spider plant (Cleome gynandra) are among African leafy
vegetables (ALVs) that are consumed in Kenya. Studies were conducted to establish the traditional
cooking methods for ALVs and to determine quantitative changes in ascorbic acid and beta
carotene on cooking the two ALVs. Results revealed that the cooking methods had distinct steps.
The amount of time and water for cooking were unspecified. Ascorbic acid decreased from
28.2mg/100g to 1.8mg/100g in Spider plant (93.6% loss) and from 19.5mg/100g to 5.8mg/100g in
African nightshade (70% loss). Beta carotene decreased from 2.1mg/100g to 0.1mg/100g in Spider
plant (94.4% loss) and from 1.8mg/100g to 0.9mg/100g (50.6% loss) in African nightshade. All
results were significant (P˂ 0.001). The study concludes that there are existing methods of cooking
ALVs. For the two ALVs, cooking led to drastic losses of ascorbic acid and beta carotene. Losses
from the African nightshade were generally lower than from the Spider plant for the same nutrient,
under similar processing conditions. The study recommends procedural changes in processing
methods so as to conserve the two nutrients.

KEYWORDS: ALVs, cooking, Beta carotene, Vitamin C