PASTEURISED MILK.

New Zealand Herald, Volume LXV, Issue 19962, 2 June 1928, Page 8

PASTEURISED MILK.

EFFECTS OF THE PROCESS. a valuable; safeguard. SOME PRECAUTIONS NEEDED. NO SUBSTITUTE FOR CLEANLINESS In a public address this -week, Dr. Bsvan-Brown, acting-director of the pathological department of the Auckland Hospital, drew attention to the fact that by no means a'i ths milk sold in Auckland is pasteurised.. As pasteurisation is the recognised method of rendering milk as free as possible from disease bacteria, the question is one of some public interest. To provide a pure milk supply for a city so largo as Auckland is not a simple matter, 3i)d ths difficulties cannot bo overcome merely by ordering that all milk should be pasteurised before s*le. This is recognised in the New Zeaknd health legislation, which, unlike that of some other countries, docs not, make pasteurisation compulsory. It goes no farther than to define the treatment which entitles milk to bo sold as " pasteurised." Tho problem really begins at the dairy farm. If the milk is not obtained from healthy cows under cleanly conditions, it may become not only dirty but also infected. with tho germs of various diseases. The primary remedy for this is care on the part of tlie dairyman, supplemented by official inspection. Effects ol Pasteurisation. l'asteunsation is regarded by all authorities as no substitute for cleanliness in the dairy, but only as an adjunct thereto. "Inspection gives us cleaner and better, but not necessarily cafe, milk," savs a standard work on the subject- "-Pasteurisation destroys title dangers inspection cannot, see. It is the simplest, cheapest, least objectionable and most trustworthy method of rendering infected milk safe. Pasteurisation, however, cannot atone for filth, and sliould not be used as a redemption process." If properly carried out, namely, by heating the milk to 150 deg. Fahrenheit, holding it at that temperature for 20 '•minutes, and then cooling it quickly, pasteurisation frees the milk from, tho bacteria of tuberculosis, typhoid, scarlet fever, diphtheria, iJnd several less common diseases. After treatment, the milk should be put into a closed vessel and kept in as cool a place as possible. There are several reasons why in New Zealand pasteurisation has not been mado compulsory. Tho standard of cleanliness in dairies is a. good deal higher than in older countries, and the herds, being de pastured all the year round, are much less liable to bovine tuberculosis, than those that are housed through the winter. In the second place, numbers of small dairy men supply milk direct to consumers in their neighbourhoods, especially in the lesser towns, and it would be difficult to ensure that the process was properly carried out, if at all, seeing that such vendors deliver to their customers within an hour or two of ztiilkiDg. Liability i& Contamination. ■ Pasteurisation, although it does not affect tho taste of the milk and is undoubtedly a valuable preventive of' disease, has some drawbacks. it does not safeguard the milk against further contamination, as many people imagine, i Raw milk contains certain "enzymes" which hinder, although they do not prevent, the multiplication of foreign bacteria. These " enzymes " are destroyed by pasteurisation. It is found that if pasteurised and raw milk are left exposed to the air under similar conditions, the pasteurised sample has for a time tho lower bacterial content, but la.ter its germ I population increases far more rapidly than that of the raw milk. Other changes are more pronounced, and eventually a point is reached at which the pasteurised milk forms into a single large clot and j becomes highly offensive, whereas the ' other sample is merely sour. However, chilled- pasteurised milk has been known to keep for weeks. As regards food-value. • it does not appear that much is sacrificed by the process. Yitamine C, the lack of which produces scurvy, is reduced by about onehalf, but can readily be replaced by fruit and other items of a mixed diet. The authority already quoted says on this point: "There can be no more objection to the heating of milk for the use of adults and children above the age of three years than there is to the ' cooking• of meat. Infants should receive breast Eiilk. When this is not possible they should have the best, freshest cow's milk tint can be obtained. Whether such milk is to be' pasteurised, modified or otherwise treated will, vary with circumstances." The Plunket Practice. The practice of the- PJ.unket Society,, which had proved its effectiveness beyond any question, shows that pasteurisation or boiling is an essential part of the preparation of humanised milk. Karitane homes throughout the country do not relv on the process as carried out by milksupply concerns. They buy the best and freshest raw milk obtainable, preferably from mixed herds. This is prepared for the babies' use by adding a mixture of dextrose, milk-sugar and some gelatin", and an emulsion containing cod-liver oilThe whole is then either pasteurised or boiled, the latter being now considered preferable. The emulsion is rich in vitamine A, and any lack of vitamine C-. previously referred to, is made up by giving the infant orange-juice or carrot-juice as a matter of routine. It is very seldom that Outbreaks of any kind of disease in New Zealand arc traceable to contaminated milk supplies. However parents of voung children can provide a. safeguard with little trouble by buying pasteurised nnlk or by carrying out the process in the home. In either case the milk should be protected most carefully from contamination until «it is actually consumed.