Abstract:
This study investigated the physicochemical properties and bacteriological quality of selected branded and packaged sachet water in southwestern Nigeria and their stability under different storage conditions. Eighteen sachet water brands, packaged by different manufacturers, which were freshly processed, produced and supplied and are popularly consumed drinking water from highly populated environment were used for this investigation using multistage random sampling technique. Analyses were carried out for physical quality (odour, taste, colour, pH, electrical conductivity and total dissolved solids), chemical quality (carbon dioxide, methyl orange alkalinity, total alkalinity, total hardness, and chloride), microbiological composition/analyses (total mesophilic counts Pseudomonas aeruginosa and Escherichia coli), and mineral composition (calcium magnesium copper, lead, cadmium, zinc and iron). Analyses were done on the collected samples and monthly for three months under different storage conditions. The results revealed that the various parameters were within recommended standard range in the waters, except for a few samples. The pH values, ranging between 4.90±0.13 and 7.90±0.13, were generally in agreement with the standard pH range of 6.5 – 8.5. Phenolphthalein and methyl orange alkalinity tests indicated that the waters were not rich in carbonates and bicarbonates.All the values for total hardness recorded in the present study are found to be lower than the specified SON limit of 150 mg/l for hardness as function of calcium carbonate. The values for chloride in the sachet water samples were significantly (p<0.05) low, probably because the common practice in Nigeria is ozonation. The coliform counts of the samples in this study showed that some of the sachet water samples were not fit for consumption as they had high coliform and E. coli counts. The five samples that showed detectable Cu concentrations
