The role of water in Food Processing.
- Ingredient use
- Cleaning and sanitising
- Waste disposal
- Drinking and handwashing
- Heating
- Water recycling
The water should be safe and of the proper quality for each application, and quality and maintenance programs are critical..
Water Sources
- Borehole/ well
- Municipal water
- A body of water, such as a river, lake, or sea.
A fish farm, for example, in a remote area may be built to include water treatment plants.
Also, the water source may be from two or three different sources, such as a canal, a borehole, or a dam.
Quality and Safety
Water is a potential source of Human pathogens, such as Coliforms and Escherichia coli, which are very likely to be found in raw water. Cryptosporidium parvum could be found in water from a flood or poor drainage. All water sources should be subjected to stringent water quality in food industry tests.
For example, municipal water standards stipulate no more than 100 coliforms per mL and zero E. coli, but contamination could occur after the water leaves the treatment plant. Food Processors must develop a program to monitor the water’s microbiological quality. Water samples from locations furthest from the inlet pipe should be collected every three months.
Tested water samples should be taken after 5 minutes of running. Water samples can be stored in a sterile container, preferably supplied by the contract laboratory, or in sterile specimen bags.
- Thiosulfate tablets must be used to neutralise chlorine in the sample.
- The samples should be labelled with the date and time of sampling.
- If using a contract laboratory, ensure the laboratory is certified in food processing water.
- Styrofoam containers containing ice or ice packs can be used for the samples, which should be delivered as soon as possible and arrive at the laboratory within 30 hours of sampling.
- Corrective actions must be initiated if any samples do not meet established standards.
Samples should be tested for:
- Nitrates
- Nitrites
- Arsenic
- Water hardness
- pH.
If there are concerns about water quality or the water system, additional chemical testing for specific heavy metals may be needed.
For example, metal testing may be necessary if a city’s pipes are old or there are concerns about lead.
One of the most crucial water uses in food manufacturing standards is hardness (Table 1). Water hardness significantly affects many of the applications.
| Class | ppm |
| Soft | 0-60 |
| Moderately hard | 60-120 |
| Hard | 120-180 |
| Very hard | >180 |
Role of Water in a Food Processing Plant
Water is an ingredient in many products, from beverages to baked goods. Bottled water and soft drink plants establish in-house treatment programs for their water. Sand filters, ultraviolet treatment, ozone and charcoal filters should all be included in the water treatment process.
Maintenance and backwashing of charcoal filters are essential to prevent Pseudomonas growth. As ultraviolet light bulbs have a shelf life, replacing them at least annually is essential. A residual ozone level of 0.2 ppm cannot be exceeded in the bottled water. Hard water can adversely affect some bakery products, so processors must understand their products and the ingredients that go into them. pH, acidity, and alkalinity will also affect chemical leavening agents and enzymes, dough characteristics, and bread quality in yeast dough.
Gluten structure and retard fermentation is affected by hard water. Soft water, on the other hand, lacks minerals that strengthen GL, which creates smooth, sticky dough. Mineral nutrients necessary for yeast may be absent in soft water..
Cleaning and sanitising processes play a role in water chemistry. Water samples should be obtained from all sources to ascertain chemical requirements. Hard water reacts with some products, and a redeposit film from hard water could react with some products. Heated water in boilers should have a softening system to ensure high performance and proper boiler maintenance.
If water is reused or recycled, it must be monitored regularly.
Tests should include:
- Microbiology—total counts, coliforms, E. coli
- pH
- Residual chlorine/sanitiser.
Monthly inspection records of cleanliness and other factors should be kept.
Handling Water in the Food Plant
Water entering the facility must be of high quality and safe.
A backflow device should be fitted on all water inlets and lines with one-way nozzles/valves. The location and functioning of these devices should be the subject of an annual audit.
Updated drawings of all water, wastewater and steam lines should be available.. The diagrams shall clearly show no cross-connections between potable water and wastewater lines. Water, wastewater, and steam lines shall be appropriately labelled using a colour-coded system—for example, green for potable water, black for sewage, and red for steam. The annual internal audit program of the plant layout is essential, especially with any changes made.
The plant manager should ensure proposed plumbing changes are part of the change management process. Cross connections can adversely affect food safety and quality, resulting in consumer illness. Off-flavour, such as staleness, could result from a dead space in the plumbing. For example, a large old storage tank could be a source of contamination or staleness.
In this case, a UV-treated water system may be necessary. Underground tanks should be inspected to ensure no outside contamination from water. Steam generation management and boiler chemistry programs are essential. The chemicals used must be appropriate for the operation and application. Organic processors to accommodate “kosher” requirements may exclude chemicals for boiler treatments. Boiler compounds containing sulfites could be transferred to food directly with steam. A food product with≥10 ppm sulfide levels should be declared on the label. In-line steam traps are essential to ensure the steam remains high quality and should be routinely checked.
If the facility uses steam for food contact, a program to produce and maintain a culinary steam system with 5-micron filters in-line to remove particulates is essential. These filters must be part of the preventive maintenance program, which is regularly checked, maintained, and replaced. It is also necessary to check the steam lines to ensure they are correctly installed.
The flowing steam could pick up accumulated moisture from dips or drops in the line. Ice machines should be cleaned and sanitised regularly (more so if ice is used as an ingredient). Ice samples shall be collected at six-month intervals and tested using the same procedures as the plant water.
Summary
In the food processing industry, efficient water treatment is probably the most important aspect of managing water in food industry operations. Processors must establish programs to monitor and maintain water quality, as the destructive consequences of poor water management or foodborne illness incidents cannot be overemphasised.