Abstract
In dairy manufacturing plants, the presence of biofilms in pipelines, around seals, and on product contact surfaces in processing equipment such as pasteurizers and evaporators is believed to be a significant source of product contamination. In dairy manufacturing plants, biofilms are often comprised of specific species that are well adapted to survive the extrinsic (heat, cooling) and intrinsic (pH, salt) factors associated with milk processing. Biofilm formation is becoming more problematic as processing plants increase in complexity, providing more niches for microbial growth, and as manufacturing run times lengthen, allowing more time for cell growth. Bacteria attached to surfaces are more difficult to kill than free-living cells, and contamination from biofilms increases the microbial load and potentially the safety and quality of dairy products. Minimizing biofilm initiation and subsequent growth is therefore an increasing challenge for dairy manufacturers. Some of the initiatives that may help are improving the handling of raw milk to minimize the initial microbial load, developing alternative clean-in-place chemicals/regimes, using modified materials that resist microbial colonization, and employing variations in operating conditions within the manufacturing plant in order to produce unstable conditions so as to disrupt the microbial growth.