Storage Effects on the Quality of Sachet Water Produced within Port Harcourt Metropolis, Nigeria

The present investigation highlights the effect of storage on the physico-chemical status and bacteriological quality of sachet water produced in Port Harcourt, Nigeria for a period of four months. Ten brands of sachet water were collected within 24 hours of production and stored at ambient temperature. Sub-samples were drawn from the stock samples on monthly basis for physico-chemical measurement and on weekly basis for enumeration of total aerobic heterotrophic bacteria and indicator organisms using ASTM, APHA and WHO analytical methods. pH values increased in all brands to acceptable WHO limits within 8 weeks of storage and gradually decreased toward the end of the experiment. Dissolved oxygen, volatile organic matter and nitrate values decreased throughout the investigation period while phosphate and potassium values increased throughout the investigation period in all brands tested. Total aerobic heterotrophic bacterial count increased gradually in all brands to unacceptable limit within four weeks of storage and gradually diminished to zero level by the end of experiment. Total and faecal coliform appeared in 40% of sachet water samples analyzed within the first three weeks and were no longer detected throughout the investigation period. Escherichia coli was isolated in one brand at the onset while faecal Streptococci were absent throughout the investigation period. Results of the experiment indicate that 60% of the brands analyzed met the WHO guideline limit for drinking when stored at ambient temperature within four week period. However, storage beyond this period led to diminished aesthetic quality of sachet water and increased proliferation of bacteria to a level deleterious to human health.