The Effect of Black Soot on the Proximate and Phytochemical Properties of Plants in Okrika, Rivers State, Nigeria

The study investigates the effects of black soot on the proximate and phytochemical properties of plants exposed to it, following the fear that black soot may have direct and indirect effects on vegetation when airborne or buried in the soil. To this end, samples of the plants (cassava and melon) cultivated under the black soot prevalent condition and samples of a control (that are cultivated in an environment not exposed to black soot) were analyzed to assess their proximate and phytochemical contents. The results of the proximate analyses that was conducted on cassava and melon samples cultivated in black soot contaminated soil and that of the control revealed that: the effect of black soot on the proximate composition of cassava/melon increased the moisture content from (3.98/15.35 - 6.73/24.35%), crude protein (2.74/3.73 - 3.13/4.65%), and fats and oil (8.68/4.89 - 12.15/14.93%) compositions and decreased the ash content (0.41/0.27 - 1.15/0.56%), crude fibre (0.05/0.43 - 0.08/0.57%), and carbohydrate (26.38/9.09 - 30.05/14.00%) compositions of the crops (cassava/melon and from control to soot affected plants respectively). Likewise, the effects of the black soot on the phytochemical content of the crops increased the flavonoids (122.21/70.65 - 201.20/106.82 mg/100g), phenolics(92.92/50.46 - 120.00/68.43 mg/100g) and alkaloids (13.15/44.53 - 21.18/71.80 mg/100g); and then decreased the saponins (3.40/7.49 - 2.55/5.45 mg/100g), terpenoids (3.37/4.03 - 1.24/2.05 mg/100g), tanins (3.21/6.01 - 2.90/4.51 mg/100g) and stilbenes (199.10/279.02 - 143.01/205.52 mg/100g) contents respectively of the crop pair. Hence, black soot had both negative and positive effects on the proximate and phytochemical contents of the plants.