Digestibility of Leaf Proteins of Gnetum spp Vegetables in Rats and Effects of Some Antinutrients

Aims: Study leaf protein digestibility and effect of some antinutritional factors of Gnetum africanum
and Gnetum buchholzianum on young male rats Wistar albinos.
Study Design: Nutritional enhancement of use of Gnetum spp leafy vegetables.
Place and Duration of Study: Limbe botanical Garden of Cameroon, between November 2013 and
February 2014.
Methodology: Proteins and antinutritional factors were determined using standard analytical
methods. Standard diet AIN-93 was used as reference for preparation of experimental diets used for
in vivo digestibility of these leafy vegetables. Rats were fed with diets containing respectively 5% or
10% leaf proteins of G. africanum (GA5P or GA10P) or G. buchholzianum (GB5P or GB10P).
Results: Results showed that mean proteins contents was 16.70 mg/100g. Average contents of crude
fibers, Neutral Detergent Fibers, Acid Detergent Fibers, crude phenolic compounds, tannins and
phytates were respectively 36.17, 41.97, 37.80 g/100 g and 478.80, 244.94, 215.64 mg/100. Rats’
growth was more promoted by diets containing 5% proteins. Protein Efficiency and Net Protein
Efficiency Ratio were low. Digestibility Coefficient, Biological Value and Net Protein Utilization were
high for 5% proteins diets. Principal Component Analyses revealed that fibers and antinutrients
reduced growth and nitrogen retention from diet containing 10% proteins.
Conclusion: Gnetum spp. leafy vegetables have high contents of fiber, phenolic compounds and
phytates which contribute to reduction of digestibility of theirs proteins.