Bottled
water can be spring, well or purified water. The standards
for bottled water set forth by the FDA require that no more
than one coliform organism be present per 100 ml of water.
No heterotrophic (aerobic or total) plate count limit is
specified in the standards. Ozone is typically used as a
disinfectant. It is applied just before bottling. As a result,
bottled water is typically coliform-free with very low heterotrophic
plate counts at the time of bottling. However, bacteria multiply
during storage after the ozone has dissipated. The predominant
microorganisms are the gram-negative bacteria of the genera
Pseudomonas, Flavobacterium, and Moraxella-Acinetobacter.
These microorganisms are not of significant importance and
do not result in microbial spoilage or flavor impairment
of the products. However, spoilage has been reported caused
by molds. The presence of coliforms serves as an indicator
of lack of Good Manufacturing Practices and a potential health
hazard.
Recommended tests:
Heterotrophic plate count.
Total coliform count.
E. coli.
Test of containers and closures for Total Coliforms and E. coli.
Additional tests:
Yeast and molds in the case of spoilage.
Adapted from:
Kim, H. and Feng, P. 2001. Bottled Water, p. 573. In F. P. Downes and K. Ito
(eds.), Compendium of Methods for the Microbiological Examination of Foods. American
Public Health Association, Washington, DC.
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