Water Quality and Safety: Tips for Food Processors On Establishing Programs to Manage Water

Some U.S. states require pesticide testing of well water. Water samples for complete microbiological and chemical analyses should also be collected at least once a year and submitted to a recognized water testing laboratory. Testing the microbiological quality of the water should be done more frequently and, if the source is a well, every quarter at a minimum.

Processors must establish documented programs for water sampling and testing. These protocols should include how to sample, how often to sample, where to sample, and how samples should be stored or shipped. These procedures should also include what tests should be done, methods for doing the work, and what to do if a sample fails to meet established specifications. Records and testing procedures should be maintained in a separate file or binder so that test results may be quickly and easily accessed. Of course, many operators are now maintaining records electronically. The key is easy access.

Installing sample ports on water lines is a good idea, provided they are installed properly, which means do not leave a large dead-leg. It is also a good idea to allow the sample port to “run” for a short period to flush the port before collecting a sample. If water samples are being collected for microbiological testing and the water is chlorinated, be sure that the sampling program includes a step to neutralize any residual chlorine. Sample bags that include a sodium thiosulfate tablet will meet this need. Since these bags are plastic, they’re safe to use in any kind of processing environment.

Water as an Ingredient

Water is used as an ingredient in many products. The quality—the chemistry of the water—required depends on the product being manufactured. For example, baked goods do not contain large amounts of water, but the chemistry of the water can affect doughs or batters, and eventually the finished baked good. Water also acts as a solvent for salt, leavening chemicals, sugars, and emulsifiers.

Water may also contain dissolved minerals, organic matter, gases, and microbial contaminants. The degree of hardness is generally expressed as hard, soft, saline, or alkaline. The specific composition is expressed in parts per million (ppm) of the dissolved hardness-causing minerals, which are mainly calcium and magnesium salts.

Here are examples of how hard water may adversely affect the quality of baked goods:

• Calcium and magnesium may precipitate from hard waters in steam lines and can then be carried by the steam used in bakery ovens, which may cause spotting on the top crust of breads and rolls.
• Calcium sulfate is the primary component of scale formed on boilers and is generally considered undesirable. Calcium sulfate in a dough system stimulates yeast activity and has a strengthening effect on gluten structure. The salt is often added if the water is soft.
• Calcium and magnesium bicarbonates create highly alkaline water, increasing the buffering capacity of the water and potentially resisting the ability of acids to lower the pH of the product. Yeast and enzymatic activity may be compromised in doughs made with alkaline water, as the pH remains above the optimum range. Water treatments or formula adjustments can be made to compensate for this condition.

Water quality is extremely important in beverage operations. Soft drink and bottled water producers using city or spring water may subject water to the following steps: sand filter for foreign material control, charcoal filter to remove chlorine and volatile organic compounds, reverse osmosis to remove minerals, and ultraviolet light and ozonation to control pathogens. In bottled water, ozone levels must be greater than 0.2 ppm and not exceed 0.4 ppm. Fortunately, a bottled water operator that exceeds the upper limit for ozone can hold product and allow excess ozone to dissipate. Whenever ultraviolet light is utilized as a sterilant, the company must incorporate the UV light into the preventive maintenance program to ensure that efficacy of the light treatment remains high.