Quality and Safety of Local and Imported Natural Mineral Water

Abstract

       Natural mineral water is water obtained directly from natural or drilled sources from underground water. It is normally rich in some kinds of mineral known to be beneficial to health. The concentration of minerals depends on the location of the sources. It is categorized as food and regulated by the Ministry of Public Health. Increasing brands of both locally produced and imported products in markets indicate the increasing acceptance by consumer in Thailand. Although it is normally bottled at source, it may be contaminated naturally or by industrial activities. Therefore in the fiscal year B.E. 2556, the Bureau of Quality and Safety of Food conducted a study on the quality and safety of mineral water distributed in Thailand. The total of 54 samples (21 locally produced and 33 imported) was analyzed for 13 minerals and trace elements. These were Pb, Cd, Cr, Cu, Mn, Ni, As, No₃ and F which are regulated because they can be harmful to health and Ca, Mg, Na and K which are not regulated but essential to health. The analytical techniques used for analysis were AAS and IC. The results showed that 90.7% of the samples complied with the regulations and 9.3% (5 imported samples) did not comply due to the levels of cadmium which exceeded the standard limit of 0.003 mg/L. The data were analyzed statistically. With Pearson Chi-Square and Fisher Exact Test, the results showed that at α =0.05 there was no significant difference between the numbers of local and imported samples containing Pb, Cd, Cu, Mn, Ni, and As. For Cr and No₃, the number of imported samples were significantly higher than the local products. With Mann-Whitney U test at α =0.05, it was found that the local products contained lower levels of Ca and Mg but higher Na. For K, no significant difference was observed. In conclusion, the quality and safety of both local and imported natural mineral water complied with the regulation. For Cd, monitoring should be carried out, especially in imported products, to protect the consumers and to facilitate the enforcement of the regulation.