Comparative analysis of phytoconstituents in commonly used vegetables in gas flaring and non-gas flaring communities in southeastern Nigeria

A comparative study to determine the impact of gas flaring (GF) on some phytoconstituents of five commonly used green leafy vegetables was done. Two locations in south-east states in Nigeria, Ibeno in Akwa Ibom State, a gas flaring (GF) community and Nsukka in Enugu State, a non-gas flaring (NGF) community, were used. Five fresh green leafy vegetable samples were used for this study (Amaranthus hybridus, Gnetum africanum, Talinum triangulare, Telfairia occidentalis, and Vernonia amygdalina) and were obtained from community farmlands during the rainy season between August and November, 2016. After collecting and identifying the green leafy vegetables from five different farmlands in GF and NGF areas and at a distance of about 2km radius from the flare site in GF communities, detailed laboratory analysis was done for alkaloids, flavonoids, saponins and tannins. For A. hybridus, the flavonoid and tannin contents in NGF community were significantly (p<0.05) higher than in GF community; G. africanum, the alkaloid and tannin contents were higher in NGF community; T. triangulare, the alkaloid content alone was higher in NGF community; T. occidentalis, the alkaloid, flavonoid, saponin and tannin contents were significantly (p<0.05) higher in the NGF community; V. amygdalina, the tannin content alone was higher in NGF community compared to the GF community. Most green leafy vegetables from NGF community produced higher and better phytoconstituent concentrations than the GF community. This can be attributed to the non-pollution of the former environment.