Comparative evaluation of the physicochemical composition and microbial quality of seven different water sources used in processing root and tuber crops in Umudike, Nigeria

Abstract

The physicochemical composition and microbial quality of 7 different water sources (Umudike ukwu bore hole (B5), Umuariaga borehole (B3), Nidoro spring water (S2), Umudike bore hole (B4), Umudike school borehole A (B7), Umudike school bore hole B (B6) and Ahiaeke bore hole (B9) used for root and tuber crop processing in Umudike, Nigeria were investigated using standard techniques. The chloride, sulphate, phosphate, dissolved substances, hardness of water, ammonium nitrate and conductivity in all the water samples, fell within the range recommended by the Nigerian Industrial Standard (NIS) or the World Health Organization (WHO) while the values obtained for pH and nitrites were lower than the range given by WHO and NIS. Most of the samples had higher organic carbon contents than permitted. In terms of dissolved oxygen (D) and total hydrogen (TH), S2 had the highest, B5 and B6 had the least for DO (P > 0.05) while B6 had the least in addition for TH. The biochemical oxygen demand (BOD) of B3 was the highest among the water samples analyzed (P < 0.05) while that of B5 and B6 were the least (P > 0.05). Sensory evaluation of the samples showed that they were clear, tasteless and odorless. Microbial analysis carried out indicated the presence of coliforms in the water samples although this does not give any cause for concern as they fell within the standards for coliform in water. The total plate count of the samples ranged from 8.00 to 19.09cfu/100ml with B9 having the highest while B7 had the least. Some of the microorganisms isolated include: E.coli, salmonella, shigella, fungi and staphylococcus, indicating microbial contamination of these water samples and thus highlights the need for their urgent sterilization. The absence of Vibrio cholerea in all the water samples indicate the non-prevalence of cholera in the study area. Finally, most of the water sources used by these communities in processing their root and tuber crops did not meet the recommended standards for nitrites, biochemical oxygen demand, organic carbon and nitrites in water, underscoring the need for regular checks and on these water sources.

Key words: Water, microbial, coliform, physicochemical, root crops, tuber crops.