EQUIPMENT ▶▶▶
Basic requirements for sanitation at the processing facilities are effectiveness, economy and safety. An effective and safe sanitation regime reaches economic effectiveness if the sani- tation agent can be easily washed out, has low demand on energy, is highly effective and offers the least damage to the environment and disinfected surfaces. In this study, the re- searchers also showed that bacterial strains with “qac genes” were able to grow in a high concentration of benzalkonium chloride, which is commonly used as a disinfectant. They con- cluded that, by understanding biofilms, control strategies can be developed to control the proliferation of the microbial population in the dairy environment.
Bacterial bio- films occur at all stages of dairy processing, from raw milk collection through to waste treatment.
were formed by bacteria of Streptococcus agalactiae and Lactobacillus spp., corresponding to 28–58% of cases.
Are disinfectants effective? The major problem with cleaning and disinfection of biofilms is their resistance to chemical treatment. In their study, re- searchers at the National Technical University found that bio- films of P. aeruginosa of dairy origin were resistant to three disinfectants: benzalkonium chloride, iodophor and sodium hypochlorite treatment. In the same study, the influence of another batch of disinfectants used for the sanitation of dairy equipment at milk-processing enterprises was evaluated. The preparations included active substances such as quaternary ammonium compounds, chlorine and nanoparticles of silver. These preparations ranged from having no effect to being weakly effective against film-creating bacteria forming. Fur- thermore, it was also established that working solutions of disinfectants P3-ansep CIP, Eco chlor, Medicarine and Maxidez were less effective on biofilms. However, one disinfectant stood out: the Р3-oxonia active 150, a disinfectant based on hydrogen peroxide/peracetic acid. It is worth noting that some studies suggest that although sanitis- ers based on peroxygens can eliminate spores, they are usual- ly corrosive at high temperatures and concentration. The current study was done at the low temperature of 17°С.
Surface disinfectant According to ECOLAB, P3-oxonia active 150 is a surface disin- fectant that can be used in the dairy, beverage and food pro- cessing industries, as well as for sterilisation of aseptic pro- cessing and packaging equipment. It is effective against all types of micro-organisms (broad spectrum) but most efficient at low temperatures. It is also pH range tolerant, being effec- tive from acidic to neutral pH. It is environmentally friendly, having a minimum amount of phosphate and zero chlorine.
24 ▶DAIRY GLOBAL | Volume 7, No. 4, 2020
Alternatives to disinfectants The use of quorum sensing inhibitors to prevent biofilm for- mation is a recent technique for further exploration. During quorum sensing, bacterial cells communicate through cell-to- cell signalling to regulate their physiological processes as they growth to mature biofilms. Another possibility is to ap- ply surface coatings; some studies have shown that modifica- tion of stainless-steel surfaces using Ni-P-polytetrafluoroeth- ylene or sol-gel (thermolon) can significantly reduce bacterial fouling, leading to reduced biofilm formation during milk pasteurisation. Several phytochemicals have also been re- ported to be effective in inhibiting biofilm formation; how- ever, their limitations could be the development of flavours in the products. Another possibility is the cavitation treatment, where the cavitation will inactivate bacterial spores to reduce their ability to adhere to surfaces.
Cleaning efficiency High cleaning frequency is important since the resistance of biofilms to chlorine has been reported to significantly in- crease as the age of biofilm increases. The quality of water is also crucial; flush water can be a major source of microbial contamination. It is ideal for dairies to determine the pres- ence of micro-organisms in the final flush water – this should not exceed the permissible total viable counts. Several stud- ies show that the most contaminated surfaces are the areas located after bends, which means cleaning strategies should pay more attention to these zones. To achieve the most effec- tive cleaning-in-place results, it is necessary to design all equipment with equal consideration to production and cleaning requirements.
This article is based on the original articles by Flint S, Bremer P, Brooks J, Palmer J, Sadiq F, Seale B, Teh KH, Wu S and Md Zain SN. 2019. Bacterial fouling in dairy processing. International Dairy Journal,
https://doi.org/10.1016/j.idairyj.2019.104593; and Kukhtyn M, Berhilevych O, Kravcheniuk K, Shynkaruk O, Horyuk Y and Semaniuk N. 2017. The influence of disinfectants on microbial biofilms of dairy equipment. Food Science and Technology, DOI:10.21303/2504-5695.2017.00423.
PHOTO: RONALD HISSINK
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28
