BACTERIA AND MILK.

New Zealand Herald, Volume LXIII, Issue 19397, 4 August 1926, Page 18

BACTERIA AND MILK.

INSPECTION OF CHURNS. A DIFFICULT PROBLEM. Professor James Long, writing on bacterial, contamination in the Lincoln Mercury, says : —An attempt was made by officers of the Research Station attached to Edinburgh University during October and November to examine 500 empty milk churns on the platform of a railway station, and there could be no better place for their inspection.. Each churn was examined for its apparent cleanliness, for its condition in regard to its odour, and, lastly, for the number of bacteria which were found on subsequent examination after the washing of the churns, where sterile saline solution had been used in washing the interior. It is quite clear that imperfect cleaning is indicated by the presence of either milk or milky water, or of a foul odour, and • unless the churn was thoroughly cleansed by the farmer before again being filled, the only result that could follow would be the contamination of the milk that passed into it.

Now let us come to facts as they "were found by inspection, at a time, be it remembered, when milk does not become sour owing to the heai of the air. The churns, which were apparently clean and sweet, were divided into 81 dry and 140 wet. Where there was no evil smell and where milk was absent—i.e., the drainings —there were 5 dry and 118 wet. Eightyone other churns containing milk were not washed at all, while seventy-five others were badly washed. Such were the results of inspection, which alone would establish the fact that an enormous majority of the churns were unclean, and, therefore, unfit for use until they had been perfectly cleansed.

I have remarked that the churns were washed with a solution. Samples of these washings were taken in sterile bottles, and subsequently examined for bacteria within an hour of their collection, to the details of which I need not refer. It subsequently appealed that the cleanestlooking churns had not been cleansed thoroughly, nor can thoy ever be under the present conditions of management, whether on farms, factories, or the premises of retailers. In every case bacteria were found, sometimes in enormous numbers. Now it must be remembered that, although milk contains a very large number of bacteria under the ordinary circumstances by milking, cooling, transit by rail, and subsequent treatment* by the recipients, the liquid tested in these cases were simply the. washings 'of the churns. The best samples tested contained 170 bacteria per cubic centimetre of the washings, so that a given measure of the solution was used. The examiner estimated that each churn contained 170,000 bacteria. In conclusion he says: The time will come, perhaps shortly, when it will be possible to sterilise the churns so -that they may be perfectly free from bacteria, but this will not prevent the presence of bacteria in milk;, although ii will prevent their 'initial , contamination from dirty churns.' The existing position of transit of the churn, and the miik whioh is pasteurised and cooled on arrival, and then poured into another churn for delivery, is of itself a sufficient oause for suspicion, for this is followed by milk being drawn into a can and then poured into a jug which is presented to the milkman by the housekeeper for its reception. All these questions arb detrimental to purity, and jinW scree means are found of abolishing theo; and placing the milk upon ti.s tab 1 ,? of the consumer in the condition io which it left the farm, assuming the farmer to send it as he should do, there will be finality to any attempt to ensure purity.