Contamination of microbial foreign bodies in bottled mineral water in Tokyo, Japan

Standards Compliance and Health Implications of Bottled Water in Malawi

Many people around the globe prefer bottled water especially in developing countries, where tap water is not drinkable. This study investigated the quality of bottled drinking water sold in Lilongwe city, Malawi. Compliance with Malawi Standards (MS) 560 (2004) for natural mineral water, MS 699 (2004) for bottled water and the World Health Organisation guidelines for drinking water were examined. Bottled water from different 12 brands was purchased from local stores and analysed for its pH, total dissolved solids (TDS), EC, turbidity, Ca, Mg, Na, K, Fe, NO₃⁻, Cl⁻, F⁻, SO₄²⁻, hardness, alkalinity, and Escherichia coli. A Hierarchical Cluster Analysis (HCA) resulted in two clusters in which most of the brands (92%, n = 12) belonged to one group. The two clusters and significant differences (ANOVA p < 0.05) in chemical compositions among the brands were attributed to the variations in the water source and the treatment processes. The results showed that 10 brands did not comply with the MS 699 (2004) turbidity standard (1 NTU) and the pH of one of the brands was below the minimum MS 699 (2004) standard of 6.50. This research showed that 12 brands had bottle labelling errors and discrepancies in chemical composition. The article highlighted the need for a strict inspection from the responsible governmental ministry to improve water quality and to adjust water bottles’ labels according to water characteristics.

Microbiological and Chemical Quality of Packaged Sachet Water and Household Stored Drinking Water in Freetown, Sierra Leone

Packaged drinking water (PW) sold in bottles and plastic bags/sachets is widely consumed in low- and middle-income countries (LMICs), and many urban users in sub-Saharan Africa (SSA) rely on packaged sachet water (PSW) as their primary source of water for consumption. However, few rigorous studies have investigated PSW quality in SSA, and none have compared PSW to stored household water for consumption (HWC). A clearer understanding of PSW quality in the context of alternative sources is needed to inform policy and regulation. As elsewhere in SSA, PSW is widely consumed in Sierra Leone, but government oversight is nearly nonexistent. This study examined the microbiological and chemical quality of a representative sample of PSW products in Freetown, Sierra Leone at packaged water manufacturing facilities (PWMFs) and at points of sale (POSs). Samples of HWC were also analyzed for comparison. The study did not find evidence of serious chemical contamination among the parameters studied. However, 19% of 45 PSW products sampled at the PWMF contained detectable Escherichia coli (EC), although only two samples exceeded 10 CFU/100 mL. Concentrations of total coliforms (TC) in PSW (but not EC) increased along the supply chain. Samples of HWC from 60 households in Freetown were significantly more likely to contain EC and TC than PSW at the point of production (p<0.01), and had significantly higher concentrations of both bacterial indicators (p<0.01). These results highlight the need for additional PSW regulation and surveillance, while demonstrating the need to prioritize the safety of HWC. At present, PSW may be the least unsafe option for many households.

Microbiological monitoring of mineral water commercialized in Brazil

The quality of mineral water commercialized in Brazil regarding the microbial content was analyzed and the results were compared with the standards established by the current legislation. Results demonstrated there was no bacterial contamination, but several types of fungi were found. Therefore, bottled mineral water could be considered a possible route for the transmission of filamentous fungi and yeasts.

Inactivation effects of UV irradiation and ozone treatment on the yeast and the mold in mineral water

In recent years, bottled mineral water has undergone inactivation by methods other than the traditional heat treatment during the production process; there are fewer reports of the effectiveness of these inactivation methods on yeasts and molds in mineral water than on bacteria and protozoan oocysts. In this study, we evaluated the effects of UV irradiation and ozone treatment compared with heat treatment at 85 degrees C on yeast cells and mold spores inoculated into mineral water. A 5-log reduction occurred at a UV radiation dose of 31,433 microJ/cm2 for Saccharomyces cerevisiae and at 588,285 microJ/cm2 for Penicillium pinophilum. The treatment time for 5-log reduction estimated for UV irradiation was about 0.6 min for S. cerevisiae and about 10.7 min for P. pinophilum; at an ozone concentration of 0.1 ppm, it was 1.75 min for S. cerevisiae and 2.70 min for P. pinophilum, and at a concentration of 0.6 ppm, it was 0.32 min for S. cerevisiae and 0.57 min for P. pinophilum. Comparison of the inactivation effects among the three methods showed that UV irradiation and ozone treatment were less effective than heat treatment at 85 degrees C. Thus, when UV irradiation and ozone treatment are used for inactivation of mineral water, it seems that they need to be combined with heat treatment to achieve a definite effect. Yeast cells are more sensitive to all three inactivation methods than are mold spores, and the sensitivity of yeast cells and mold spores to these inactivation methods may vary among genera.

Physiological traits of Penicillium glabrum strain LCP 08.5568, a filamentous fungus isolated from bottled aromatized mineral water

Penicillium glabrum is a ubiquitous fungus distributed world wide. This fungus is a frequent contaminant in the food manufacturing industry. Environmental factors such as temperature, water activity and pH have a great influence on fungal development. In this study, a strain of P. glabrum referenced to as LCP 08.5568, has been isolated from a bottle of aromatized mineral water. The effects of temperature, a(w) and pH on radial growth rate were assessed on Czapeck Yeast Agar (CYA) medium. Models derived from the cardinal model with inflection [Rosso et al., 1993 An unexpected correlation between cardinal temperatures of microbial growth highlighted by a new model. J. Theor. Bio. 162, 447-463.] were used to fit the experimental data and determine for each factor, the cardinal parameters (minimum, optimum and maximum). Precise characterisation of the growth conditions for such a fungal contaminant, has an evident interest to understand and to prevent spoilage of food products.

The study of fungi in drinking water

The occurrence of fungi in drinking water has received increased attention in the last decades, and fungi are now generally accepted as drinking water contaminants. The knowledge about the occurrence and diversity of fungi in water has increased considerably from a low knowledge base. However, the relevance of waterborne fungi for water quality and human health is poorly understood and still conflicting. Scientific reports on effective treatment against fungi in water are also few. This article presents a review of the literature on fungal water studies, including some general results, and considerations of significance, limits, contradictions, precautions, and practical consequences.

Mold challenge study in bottled natural mineral waters and spring waters

Microbiological challenge study was carried out to verify the microbial stability of bottled waters against four different mold species isolated from bottled water (Fusarium sp.; Cladosporium sp.; Penicillium chrysogenum and Aspergillus fumigatus) and to follow the growth of the molds in bottled water. Twelve types of bottled water with different mineralization and CO2 level in PET and glass packages were collected from 4 European countries. Three different inoculation levels of spore suspensions were used to contaminate bottled water samples. The surviving colony forming unit (CFU) numbers and visual growth were monitored during the investigation period (26 weeks). The results of surviving CFU showed that the fungal growth is mostly determined by the carbonation level and the type of the mold strain. Neither the inoculation level nor the mineral content had any significant effect on the survival of the different mold strains. Results showed decreased CFU numbers in carbonated waters, while slow decreasing, stagnation or even some growth in still waters. A. fumigatus was the most resistant test species. None of the other tested mold strains survived the first 12-week test period in carbonated water. Visual growth was not detected in carbonated water samples, in contrast to all of the non-carbonated samples.

Conditions that regulate the growth of moulds inoculated into bottled mineral water

The influence of different storage conditions (temperature, illumination, brand of mineral water and storage time) on growth of mould spores was studied. Alternaria alternata, Penicillium citrinum and Cladosporium cladosporioides spores were inoculated in bottles of mineral and mineralised water, packaged in polyethylene terephtalate (PET). The bottles were incubated under different storage conditions. The strains had been isolated from bottled mineral water in a previous study. Storage time was the parameter that had the most important influence in mould growth. The spores grew into visible colonies after 5 month of incubation in bottles just filled, and in a month in bottles that had been stored for 5 month. This could be due to the migration of compounds from PET packaging material into mineral water. This compounds could be used as nutrients (organic matter) for mould growth. The plasticizer additive di-n-butyl phthalate (DBP) concentration in recently bottled mineral water and in 5-month stored bottles was measured. An increase of 20% of DBP concentration was observed. A. alternata and P. citrinum strains were toxicological characterised. Both strains produced mycotoxins in vitro, and P. citrinum produced citrinin in mineral water, posing a potential health risk for consumers.

Growth of moulds inoculated into commercial mineral water

The growth of mould spores of Penicillium sp. and Cladosporium sp. inoculated in a commercial mineral water product was studied. The strains had been isolated as fungal foreign bodies in commercial mineral waters. In product A, which was not originally sterilized and was contaminated with psychrophilic bacteria, the inoculated mould spores of the strains did not grow; no increases in viable colony counts or beta-glucans concentration in the samples were observed during storage. In a sterilized product A, inoculated spores of the strains grew into visible foreign bodies. The viable colony counts and the beta-glucans concentration in the samples increased during storage. These results showed that in a sterilized mineral water product, mould spores could grow into visible foreign bodies.