Microbiological Aspects of Cold Cleaning with an lodophor of Milk Pipeline Installations

Over a period of three years bacteriological comparisons were made of a method of cleaning pipeline milking machines with (1) cold iodophor solution (cold method), (2) a chlorinated alkaline solution at 55-60°C circulated for 10 min (hot method), and (3) acidified boiling water (ABW method). Rinse samples from the entire installations gave the best results with the ABW method. The cold method favoured a psychrotrophic flora, coliform bacteria or lactic streptococci, depending on the part of the milking machine rinsed; the hot method tended to cause a build-up of the heat-resistant flora. In spite of this, the two methods can give acceptable results provided that the installations are correctly designed and constructed.