N.Z. Interest In New Frozen Milk Process

Press, Volume XCVIII, Issue 28980, 22 August 1959, Page 4

N.Z. Interest In New Frozen Milk Process

I from the Lpnaon Correspondent at ‘The Press’)

LONDON. August 11. Dairy companies in New Zealand and Australia have approached the National Research and Development Corporation in Britain about obtaining licences to employ the new process for producing fresh-frozen milk. So, just as British dairy farmers can now look forward to selling surplus milk abroad. New Zealand farms may eventually produce milk for Pacific countries and customers in the Far East. Market prospects in the Middle East are already encouraging, large-scale production will begin soon and exports will leave for the Persian Gulf in the coming autumn. The corporation believes there is a great potential demand for fresh frozen milk in many tropical countries where pastures are limited. Apart from the Middle East, interest is expeqted from Africa, South America, the West Indies, the Bahamas, and the Far East.

The process can also be used to stockpile supplies of milk in deep freeze to meet any sudden shortage which might occur anywhere in the world.

The milk will keep fresh-frozen for 18 months provided its temperature is kept below 8 deg. F. When this milk is thawed out it returns to a completely natural state without any alteration in condition or taste. Dr. W. G. Wearmouth evolved the process at the National Institute for Research in Dairying, at Shinfield. An ice-cream manufacturing company has been granted a licence to produce the frozen milk. The corporation holds the patent rights.

After standard pasteurisation, the milk is treated with ultrasonic vibrations of about a million cycles a second for five minutes, then poured into containers and sealed for quick freezing. Mr P. T. Plunkett, who farms in Cornwall, has been investigating, on behalf of the corporation, the market prospects of frozen milk and recently returned from a six weeks’ tour of the Middle East. He visited Kuwait. Bahrein, Beirut, and Qatar and, during his tour, trial shipments of about 700 pints of the milk were distributed to both British and foreign communities in those areas. Oil company employees, merchants, schools and the local people were enthusiastic about it. British military staff in Aden were also keen about the frozen milk, and with the expansion of cold storage

: n the Middle East, fresh frozen English milk Should in time replace existing supplies of the various canned substitutes for fresh milk which are now in' use.

Mr Plunkett also had talks with F.A.O. officials in Rome. They are interested in the possibility of distributing surplus milk in frozen form to children in refugee camps or underdeveloped countries. One shipping line is already using frozen milk. Enough frozen milk for a return trip to Australia can be loaded in the vessel’s refrigerators. before setting sail. Usually passengers have had to drink tinned milk after a few days at sea.

Cost investigations in the Persian Gulf have shown that the retail price for fresh frozen milk is only a little more than that for canned, sterilised milk. Good quality milk can be kept for at least two weeks at just above 32 deg. F. without any serious loss in its attractiveness to the consumer. Attempts have been made to keep pasteurised milk longer by storing it at temperatures well below freezing point. But, on thawing, the usual result is a product with unpleasant physical properties. Separation .of the fat in a greasy condition is one of the defects, particularly if the milk is used in tea or other hot drinks. And because of physical changes in the protein of the milk there can be a slightly clotted effect.

The new process produces none of these defects. Provided the frozen milk is kept at, or a few degrees below, 10 deg. F, its physical properties and “consumer quality” on thawing out are indistinguishable from those of firstclass pasteurised milk. It has a colony count lower than that of the pasteurised milk from which it was originally produced and shows no evidence of physical changes in the proteins. Its keeping qualities after thawing out are at least as good as those of the original pasteurised milk. Unlike mechanically homogenised milk it gives the “cream line” which is found with fresh milk after standing for a short time.