Biofilms in dairy manufacturing plant‐description, current concerns and methods of control

Abstract

Biofilms on the surfaces of dairy manufacturing plant threaten the quality and safety of dairy products. Biofilms on dairy processing lines are characterised by rapid development (< 12 h) and the predominance of single species of bacteria (e.g. Streptococcus thermophilus or Bacillus spp.). Increased processing times, more complex processing systems and demands for higher quality products have contributed to the increased recognition of the problems posed by biofilms. The growth of biofilms on the surface of plate heat exchanger pasteurizers can contaminate the milk with > 106 bacteria ml‐1 and this affects the quality of products manufactured from this milk. Biofilm control currently relies on the effectiveness of clean‐in‐place systems. A shortage of information on the development and control of biofilms in dairy manufacturing plant means that to reduce biofilm problems, increasing the frequency of cleaning is currently the only option for dairy manufacturers.