Food and food processing industry is a growing market in agrarian economies across the globe. Water is an important component of the food processing industry as it is not only present in all foods; it is also extensively used in most food plants as a processing aid as well as an agent for cleaning operations. Water is used in rinsing, dissolving, dispersing, separating and other processes within the food industry.
Given the strict food safety standards that producers within the food industry must adhere to, the use of water is also monitored under strict parameters to ensure purity of water. As per the Food Safety Standards Authority of India (FSSAI) guidelines, water is tested along various parameters, including colour, odour, pH, taste, turbidity, total dissolved solids (TDS), heavy metals present, total plate counts (TPC), pesticide residues, chlorides, fluorides, etc.
Sources and criteria of usable water:
Water used in the food industry is primarily of two types – fresh surface water and ground water. Surface water is procured from rivers, lakes and reservoirs, and may have higher levels of suspended materials, turbidity, temperature fluctuations and pesticide residues. Ground water, on the other hand, may have higher levels of heavy metal and mineral content.
Water used as an ingredient in food must be free from undesirable taste, odour, colour and impurities. In the case of bottled water, water is the key ingredient and should be tested along more stringent parameters to ensure that it is free from bacteria and other microbes.
Both bottled water as well as water used in food ingredients need to meet standards set by the FSSAI and Indian Standards Institute (ISI).
Food processors generally obtain water from private water suppliers, municipal sources or owned wells. This water should meet all the key parameters as per IS 4251 guidelines. Natural mineral water should comply with IS 13428:2005. Packaged drinking water should pass the IS 14543:2004 specifications, and drinking water should meet standards set under IS 10500.
Colour of water may vary due to many organic and inorganic contaminations, and the apparent colour is determined through the original sample before it undergoes filtration or centrifugation.
The odour of water is recognized as a quality factor which determines the acceptability of drinking water and food prepared from it. Water can possess strange odours if not cleaned and purified properly, owing to the presence of fish and other aquatic organisms in the original source.. Most organic and some inorganic chemicals also affect the taste and odour of water.
pH value is the logarithm of the reciprocal of hydrogen ion activity in moles per liter. Neutral water pH ranges from 6-8 but in case of alkaline thermal spring waters, pH value may be more than 9 while for acidic thermal spring waters, the pH may be 4.
Taste of water should comply with the standards of neutral water and be free from any impurities. Each panelist should grade water on the 9 parameters listed in the FSSAI guidelines and confirm that the taste of water conforms to the acceptable standards.
The turbidity of the sample is the reduction of transparency due to the presence of particulate matter such as clay or slit, finely divided organic matter, plankton or other microscopic organisms.
There are various chemicals and compounds present in water including ammonia nitrogen, boron, nitrate, chloride, fluoride, total hardness, alkaline compounds, magnesium, sulphates, residue of free chlorine and chloramines, sulphide, cyanide, calcium, phenol, sodium, nitrites, total solids, hexavalent chromium, mineral oils, etc. Water with high dissolved solids and chemical elements is less palatable as well as unsuitable for many industrial applications. Presence of chemicals indicates contamination, and can cause serious health issues.
Water is an essential component in food and the food processing industry and should, thus, comply with the specifications laid out by the FSSAI and the ISI . There are various types of contaminants, including those arising from both organic and inorganic sources. There are physical, chemical and microbial tests which can be undertaken to quantify water purity. Specific filtration techniques are then used to filter the water, and only when water passes the respective tests is it considered fit for consumption/use.