THE DAIRY INDUSTRY

Te Awamutu Courier, Volume 53, Issue 3823, 19 October 1936, Page 6

THE DAIRY INDUSTRY

FLAVOURS OF MILK AND CREAM. Pathological or abnormal physiological conditions of the cow may influence the flavour of milk and cream. Disturbances of the udder causing inflammation, referred to as mammitis or garget, usually give a salty taste to the milk. The causative bacteria o£ten prevent the normal souring of the cream separated from such milk and it acquires a disagreeable flavour. Mammitis milk is also undesirable for cheese-making, owing to its slow coagulation with rennet. The milk from cows for the first week after parturition, known as the colostrum, has a bitter taste and a strong odour, and is sometimes classed by graders as unclean, the term meaning that it does not possess the desirable taste of normal, cleanly produced milk. The cream from the colostrum also has a sickly, albuminous flavour and the blending of it with other creams results in the whole delivery being graded lower than choice quality by the factory. Colostrum is also quite unfit for human consumption or for cheese - making purposes. The protein lactoglobulin, which is present to the extent of only 0.3 per cent, in normal milk, varies in the colostrum from 16 per cent, immediately after calving to 3 per cent, seventy-two hours later, and only reaches the usual amount in milk after seven days. It is because of the clotting of this protein upon heating that colostrum milk cannot be boiled. The function of the colostrum is of the utmost importance for the welfare of the calf during the first days of its existence, acting as a protection against certain bacterial invasions which might otherwise prove fatal.

Milk from cows late in the lactation period possesses a bitter or salty taste, which is due to the effect of the salt content of the milk not being masked by the relatively low percentage of milk sugar at this stage. Similarly, owing to a drop in the suggar content, and a rise in the salt ratio, milk produced during a prolonged period of drought may be salty m taste.

Certain animals habitually yield milk which turns rancid. As the principle causing this rancidity attacks the fat of other milk with which it is mixed it fis sometimes found necessary to remove such animals from the herd. Pasteurisation arrest the active principle, but this is hardly practicable or economical under the ordinary circumstances in which milk is handled.