BREAD & MILK

Hokitika Guardian, 30 January 1931, Page 2

BREAD & MILK

HATS THRIVE ON DIET.

RESEARCH EXPERIMENTS.

EFFECTS OF STERILISATION.

LONDQN, December (5. Bread-and-milk, and nothing but bread-and'-niflk, from childhood to old age, is the diet of rats kept at the National Insitute of researcli in dairying, near Reading, Berks, where, with the aid of grants from the Empire Marketing Board, the products of cow and dairy are the life study of about 30 specialised scientists. Rats not only live on bread and.milk

alone; they thrive heartily, and produce large families even unto the fourth generation. There are rats whose fathers) grandfathers, and great-grand-fathers, knew no other. food,, and, far from being milksops, they are sharptoothed, trim-whiskered young rodents, ready to match their wits against a cat any day.

In the same shed are cages contain-

mg puny, emaciated rats, half the size g. :£.of theirs neighbours, and too weak to rear families. They, too, have been ; brougnt up on bread and milk, but with this vital difference—the milk has fir-sjb been sterilised, ' r "'i b" > '■ / . ;. Vitamins destroyed? Captain Golding, the daily chemist in charge of the rat experiments, be* Jieves that lie has proved the far-reach-ing fact that whereas whole milk is perfect food ' sterilisation destroys certain vitamins and other substances, and: sterilised milk therefore loses much.of its nutritional value. This is, lie thinks, of articular interest to Australia and New Zealand, where most cT the milk used for cheesemaking is pasteurised. Sterilising and pasteurising, of course are quite separate processes, and pasteurisation is not nearly so drastic. Certain changes even so, may occur in the. chemical composition of milk as a result of the “flash” method of pasteurisation, and it is possible that the \itaniins may he affected. Rats fed on pasteurised milk (and bread) seem to occupy a middle position between those oh a whole miik diet and those getting sterilised milk. An interesting fact which has come to light is that the rats which have been starved for vitamin B and are then * given unlimited supplies in the form of yeast, do not eat enough to make up the deficiency and perish in the midst of plenty. A thorough study of vitamins in milk and butter is being made, as part of a general scheme oT • vitamm lresearch into Empire produce under ■ the Medical Research Council and the Empire Marketing Bourd. CHEESE PROBLEMS. Whui is the difference. between a I Cheddar nnd a Stilton or a Cheshire , a Swiss cheese? This is one of the Problems that Reading is trying to , s|lve,i.. Scientists canpot explain in . scientific terms why such small differ- ] eTTces in manufacturing processes t should result in such very different j products. Stil Hess can they explain f why exactly similar treatment otf the } same raw material—milk—in different c parts of the country, should produce j cheeses with distinctly different flav- a ours, textures and keeping qualities. The real difficulty they are up against as Mr. A. T. Mattick, the bacteriologist explained, is that milk is so tremendously variable. Its chemical cornposit- f: ion, for instance, varies not only at- h cording to district, cow, feed, season, d and so on, but even in different quart- g ers of the same cow's udder. One of f< the most remarkable pieces of work at h Reading is a complete chemical analy- w sis of “typical milk” over several tl years. The milk is analysed everyday and a chart made of the fluctuations of its chemical contents. The chart now stretches across the laboratory and the rise and fall in the portion of butterfat, minerals of various g) sorts, casein ard so on can be seen at It

I M m

a glance. WHat are the real causes' of these fluctuations, and how do they link up with feed, pasture, age and health of Cbw .and season ? These, are the. sort of problems being tackled. They lead on to broad questions-of the influence of rations on the quality—butterfat content—of milk, about which practically nothing is known. THE MILKY FRAY. . Each cupful js a world in miniature, Milk, like water, contains thousands of ■ bacteria, all of them (in the case of “clean” or pasteurised milk supplied to the public) quite harmless to man and many of them indispensable to the dairy farmer. They make cheeses, for in dance. Cheese-making depends on a combination of bacterial, chemical anu physical factors, and bacteria are deliberately added in the form of “startera.” Bacteria, like men jure not sufficient unto themselves. Each race re- ! acts cn 'ts fellows and there is a con-stantly-changing relationship between the groups. As in the world, the population vises and falls; wars ana earthquakes (or milk-quakes) reduce it again, revolutions destroy one group and another takes its place. The life of bacteria is not a peaceful one.