外国産ミネラルウオーター類の細菌学的・化学的評価

摘要

今回，海外旅行者より供与されたミネラルウオーター類，および輸入ミネラルウオーター類の外観，細菌数，イオン成分などについて試験した．その結果，今回試験したミネラルウオーター類の一部に，微着色，浮遊物，混濁物の混入，多数個の一般細菌，従属栄養細菌が観察されたが，大腸菌群，大腸菌，腸球菌，緑膿菌は，陰性であった．また，多数個の一般細菌が存在した輸入ナチュラルミネラルウォーターの1種類について詳細に検討したところ，ロットの違いごとに一般細菌数に明確な差異が認められた．一方，イオン成分分析の結果，フッ化物イオン濃度が，ミネラルウォーター類の製造基準（原水：2mg／L以下）を超える製品があり，また，表示の必要なフッ化物イオン濃度（0．8mg／L）を超えている大部分のミネラルウオーター類に適正な表示がなされていなかった．%Overseas and imported mineral waters were subjected to visual examination, tested for standard plate count and heterotrophic bacteria, and also analyzed to determine the concentrations of several anions and cations. Some products showed turbidity or color, and several had standard plate count and/or heterotrophic bacteria. One imported natural mineral water product had a high level of standard plate count, and the levels differed with the lot. Tests for total coliform bacteria, Escherichia coli, fecal streptococci, and Pseudomonas aeruginosa were negative on additional testing of samples having standard plate counts of more than 100. The fluoride concentration of one European region sample exceeded the production standard of the Food Sanitation Act in Japan (raw water: less than 2 mg/L) and most of the products lacked the warning labels which are mandatory for fluoride concentrations over 0.8 mg/L. These results indicate that none of the raw water for mineral waters was seriously polluted, but insufficient sterilization of the bottle or cap or contamination with air-borne microbes during the production process was probably responsible for the pollution. Attention needs to be paid to fair labeling, such as no sterilizationo sterile filtration and high fluoride concentration.