The Lethal Effectiveness of Ultra Violet Rays Applied to Milk

1.The lethal effectiveness of ultra violet energy applied to smooth flowing milk films is dependent upon the intensity and spectral characteristics of the radiation employed.2.A greater bactericidal effect was obtained by ultra violet radiation applied to smooth flowing milk films than was obtained from films flowing over a corrugated cooler surface.3.The effectiveness of the lethal radiation was relatively greater per unit volume of milk when applied to flowing films than when applied to stationary films having the thickness of an adhesion layer only.4.Short ultra violet radiation predominantly in the 2200–2300Å region gave erratic bactericidal results with evidence that sub-lethal doses may cause stimulation.5.The total lethal effect of ultra violet energy and elevated temperatures simultaneously applied for less than one second appears to be an additive process.6.Percentage reduction in bacteria counts of raw mixed milk in excess of 90 per cent and frequently up to 95 to 98 per cent may be obtained with a high degree of regularity by preferred methods of applying ultra violet radiation of appropriate intensity and spectral characteristics.