Cleaning in Dairy Industry

The modern dairy industry is very complex unlike old times when it was limited to basic products like milk, butter, cheese and milk powders. But now, dairy manufacturers are providing a sophisticated and ever-changing range of products to customers all over the world. This has put pressure on existing plants to produce more with existing capacities, assure safety of the products, lower production cost and upgrade the products to higher quality standards. Recently, implemented Food Safety Standards Act has also put pressure on the Indian food industry to maintain and improve high quality standards.

The changes and pressures in the dairy industry are demanding changes in the technology used in cleaning and sanitation. The dairy industry today needs to have products which can clean and disinfect in the shortest period of time, maintain highest quality, hygiene standards and ensure that the environmental norms are fully complied with.

Cleaning and disinfecting are very complex tasks and depend on various factors like (Material of Construction) MOC of equipment, surface properties, soil composition, bonding between soil and surface, processing parameters, limitations in cleaning in terms of maximum temperature and time availability, acceptable residual chemical limit after cleaning, required degree of cleaning and disinfection, etc. These factors demand production units to apply specialised approach to maintain proper cleanliness of various surfaces, especially food contact surfaces. If surfaces in a food production plant are not cleaned to an acceptable level, they may act as a potential source of microbial growth. Further, improper cleaning may increase the utilities consumption viz. steam, water, electricity, etc.

The use of specially formulated chemicals for cleaning and disinfecting is an emerging trend in Indian Dairy Industry. Formulated chemicals are customised as per the requirement. For example, chemical with more chelating agent (to help mineral soil removal) is required for high heat-treated surfaces and for cold surfaces, chemicals with more emulsification capacity are required. There may be one or a combination of criteria for selecting a formulated chemical, like faster cleaning with savings in water & energy and cleaning and disinfection in one stage.

In dairy industry, hygiene of CIP (cleaning in place) plays a very important role. There are seven steps involved in a normal CIP-hygiene cycle starting from pre-rinse and ending with final disinfection.

• Pre-rinse
• Detergent cycle
• Rinse
• Disinfectant cycle
• Potable water rinse

Or

• Pre-rinse
• Detergent-cum-disinfectant cycle
• Final rinse

Cleaning and disinfecting chemistry that is applied depends on the soils present. In dairies, when the soil is not heat-treated and the viscosity of the product is fairly low, acidic cleaning and disinfecting can be used. This technology uses emulsification as cleaning mechanism and helps in active disinfections of the surface. The disinfection property is not lost during its use, thus this can be reclaimed and reused after topping up to the required strength. The benefits of this technology include savings in water, less energy consumption and better safety, as the chemical works on lower temperature than traditional disinfection temperature.

For heat-treated equipment, major part of the soil comprise minerals and denaturised proteins which are not possible to remove with alkali only. Acidic chemicals are used in the removal of this difficult-to-clean soil. The acidic stage can be replaced with additive package to caustic which will then eliminate or reduce the need of acidic stage. Minerals are removed by sequestration at high pH. The total impact of this would be saving time, alkali, water and energy with indirect benefits of ETP load reduction and improved productivity. This technology can be applied to viscous high fat or high protein containing non-heat treated soils also.

The dairy industry disinfection has also advanced to a higher level. The traditional method of dairy disinfection used live steam or hot water at 850C for at least 30 minutes. Practically, this method takes one hour for complete disinfection. In this process, 10-20 minutes are required for bringing the temperature of equipment surface to 850C and another 10-20 minutes are required for hot water disinfection to cool, which is required before start up of next production cycle.

The advanced technology uses peracetic acid based disinfectant which can be used at ambient temperature and requires very less contact time (5-15 minutes). Generally, it does not require any rinsing, thus maintaining the sterility of the system. Also, if required, the temperature of the plant during disinfection can be maintained at the temperature of the production. Thus, there would be no need of cooling or heating the system. This technology is applicable to both heated and non-heated soils. For non-heated soils, an acidic detergent-cum-disinfectant can be used which in turn saves water, time and energy. This process needs lower temperature than traditional disinfection and helps in simultaneous cleaning and disinfection. These new innovations in dairy equipment disinfecting save time, water and energy giving space to improve operational excellence.

Another advancement in dairy industry cleaning is cleaning of vertical surfaces which is applicable to tank exteriors and evaporator calendria. Vertical surfaces are difficult to clean as the detergent applied flows down due to gravity and does not provide sufficient contact time between detergent and soil. New products and methods of application are available to improve the retention time of the chemical. These chemicals need to be applied using foam cleaning machine. The additional cling time will yield better cleaning results as contact time will increase reducing repeat applications wherever needed. This leads to savings in time and water.

Traditionally, cleaning has never been a priority in the Indian food industry. Improperly designed cleaning protocols are in use in most of the food industries in India. Such cleaning protocols result in high microbial counts in final product, more wastage, more time spent in cleaning, high utilities consumption, continuous deposition of soils on surfaces, etc. Continuous deposition of soils even increases the complexity of the cleaning process.

Use of poorly designed protocols may affect the plant efficiency negatively. A well-designed cleaning protocol helps the dairy industry as follows:

• Improved productivity and organisational profitability
• Lesser time for cleaning, thus increased time for production
• Better operational efficiencies with savings in water, steam and electricity
• Peace of mind to management
• Improved Employee Satisfaction and Efficiency
• Better Safety.

An effective cleaning programme can be defined as cleaning to a satisfactory level with optimum costing. Cleaning process comprises various tools in use, cleaning process & process parameters and cleaning chemicals. Those days are gone when dairy industry had to stick to traditional solutions and protocols. Total solutions are now available as per the requirement which provides overall cost effectiveness with improved productivity.