الفهرس | Only 14 pages are availabe for public view |
Abstract Hussein Fahim Mohamed Abd EL-Salam: Survey on the Quality of Bottled Natural Drinking Water M.Sc. Thesis, Department of Food Science, Faculty of Agriculture, Ain Shams University, 2015. The present study was carried out to determine the physicochemical and microbiological quality of bottled drinking water (BDW) brands which available in retail shops in Egypt comparing to those of drinking water standards. Various physicochemical parameters [pH, turbidity, total dissolved solids (TDS), electrical conductivity (EC), hardness, alkalinity, chloride, sulfate, nitrite, nitrate, calcium, magnesium as well as fluoride] and microbiological analysis [total bacterial count (TBC), E. coli and Pseudomonas sp.] were considered. The changes of physicochemical and microbiological properties were recorded when the BDW was exposured to sunlight for 20 days or when stored at different temperatures for 30 days. In another side, the study deals with the suitability of using moringa seeds powder (MSP) as natural environmentally friend, alone and in combination with calcium hypochlorite Ca(OCl)2 for remediation of contaminated well water. ● Electrical conductivity changes in were initiated at 15 days of exposure in all investigated. ● Similar proportionally trend was also noticed when TDS content was followed. ● Turbidity changing was started just at 5th day of direct sunlight exposure. ● The pH and alkalinity, generally showed an decremental trend during twenty days of direct sunlight exposure started at 10th day. ● Nitrite level was clearly affected after 15 days of exposure and continuously increased till 20 days. ● Total hardness was reached to its maximum level at 15th day of exposure. ● Similar trend was strongly correlated with those of calcium hardness and calcium levels. ● leaching was started at 10th day of exposure with a noticeable level. ● DEHA level at 10th day was increased by (1.24-7.06) folds depending on exposure bottle brand. ● The aforementioned findings in case of DEHA level were similarly found in case of CH2O compound. ● The presence of E. coli in most of investigated collected brands with slightly increase at the end of experiment period. ● Salts and ions that playing the essential role in total hardness assured the earlier findings of total hardness. ● E. coli was appeared when samples stored at 45°C. ● Treated water with M. oleifera seeds extract at different concentrations lead to drastic reduction in water microbial counts. As well as, the antimicrobial activity of M. oleifera is dependent on extract dose; i.e. the lower the concentration, the lower the activity. Key words: Moringa oleifera, water treatment, Bottled water, water quality, water standards, water labeling, water storage. |