Parasite contamination impact on nutritional and phytochemical composition of Gongronema latifolium, Ocimum gratissimum and Piper guineense leaves

Abstract

Background: Consumption of raw vegetables has been implicated in the transmission of parasites. And as such the cultivation as well as harvesting should be done properly in order to avoid contamination. Objective: The impact of parasite contamination on the phytochemical and nutritional composition of commonly consumed Nigeria vegetables (Gongronema latifolium. Ocimum gratissimum and Piper guineense) were determined to ascertain the extent contamination can influence beneficial potential of these vegetables which are sometimes consumed raw.  Methods: Both qualitative and quantitative techniques were used to assess the phytochemical and nutritional composition of these vegetables both when contaminted  or not. The parasites present in the contaminated samples were also determined through floatation method and examining under the microscope. Results: Results showed that parasite contamination had a noticeable impact on the phytochemical contents of the studied vegetables. Alkaloids, flavonoids, saponin, tannin and phenol were slightly present in the contaminated leaves of G. latifolium and O . gratissimum but were in reasonable amount in non- contaminated. Dry matter was high in both contaminated and non-contaminated (88.72%) and (89.32%) in G. latifolium , (89.52%) and (89.72%) in O . gratissimum and (89.40%) and (88.40%) in P . guineense.  Fat was low in both contaminated and non-contaminated (1.70%) and (1.50%) in G. latifolium , (1.90%) and (1.70%) in O . gratissimum , (1.82%) and (1.67%) in P . guineense leaf.  Parasites such as  Entamoeba histolytica, Giardia lamblia,  Cryptosporidium spp, Strongyloides spp,  Toxocara spp. were identified in all the contaminated vegetables. Conclusion: Parasites such as nematodes and protozoa have the capability to consume or degrade proteins in the vegetables which could be the reason for noticeable reduction of proteins in the contaminated samples.. Hence, parasite contamination is capable of affecting the nutritional and phytochemical content of vegetables negatively and undermines the beneficial use of vegetables in amelioration and prevention of diseases.