PASTEURISATION

Waikato Times, Volume 105, Issue 17750, 29 June 1929, Page 22 (Supplement)

PASTEURISATION

EFFECT ON BACTERIA. NEED FOR HYGIENIC METHODS. “Pasteurisation, even under the very best conditions, is weak in that it does not destroy a sufficiently large number of the bacteria present, and that all changes the balance of the original form," declared Mr G. Morgan, bacteriologist at Wallaceville laboratory, in an address to dairy factory managers at Palmerston North. “Pasteurisation," lie remarked, “destroys practically Ihe entire flora of beneficial lactic acid producing organisms, leaving a tail end of the worst putrefactive types, and moreover types that are capable of remaining virile in butler long after it has been removed from cold stores in England. “Pasteurisation, particularly of cream, as carried out in the New Zealand butter factories, loses a great deal of its efficiency, as the plants themselves are rarely clean or sterile, and contain in their system a collection of organisms of the very worst type—escapes from former pasteurisation. The conditions of the insides of pasteurisers, pipes, and pumps from, the sanitary and bacteriological points of view leave much to be desired, • though for this state of affairs the factory manager is perhaps not. entirely to blame, insofar as he has in the past placed far too much faith in the total destruction of bacteria by pasteurisation, and has not allowed for the collection of escapes that remain and thrive in any grease or casein that may remain in the plant. One instance in particular is that of the dried casein that may be found in ihe pasteuriser. This is ’commonly supposed to be sterile, whereas it-contains many lions of organisms per gram, among' which arc usually a large number of spore-formers and heat-resisting veasts, which are particularly dangerous to salted butters in that they can work In a much higher salt concentration than bacteria.” “If the process of thorough sterilisation were carried out at the farms there would be no necessity for either pasteurisation or sterilisation at the factory, which would reduce ihe cost of production very considerably, and go a very long way towards checking the spread of mammitis which is much worse in Ncw r Zealand than in countries where hand-milking is practised, and would almost abolish the very large proportion of bad creams and milks that could never be made into either good cream or butter."