Light on Food

New Zealand Listener, Volume 13, Issue 314, 29 June 1945, Page 13

Light on Food

(Written for "The Listener" by DR.

MURIEL

BELL

Nutritionist to the Health Department)

OO much light on food — such : might be the weary complaint of a nutritionist faced with the 5000 papers that are written about food ‘each year. However, that is not the burden of the present complaint of too much light on food. It is the light of the sun that is the trouble-thaugh there is the exception in that ultra-violet: light is commercially used for enhancing the vitamin D value of milk. This is one method adopted, for example, in U.S.A. for supplying the rickets-preventive factor to babies, More usually, the effect of light is harmful. It hastens the destruction ef vitamin A in cod-liver oil, or of vitamin C in rose-hip syrup, Not only thus does it steal from the baby; for if light falls on the milk, it causes the destruction of vitamin C and .of riboflavin, one of the vitamin B factors, It also imparts a fishy flavour to the milk, "Rapid and Dramatic" We hear a great deal of misdirected criticism against pasteurisation, but we should blame light much more sternly for deterioration in the qualities of milk, If ‘no light has fallen on milk, then’ it can be pasteurised without suffering any loss of its vitamin C value. Milk is capable of providing from 12 to 15 milligrams of vitamin C per pint, about the same amount as you would get froma smallish tomato, or from an average Sturmer apple. But the effect of light, according to Dr. Kon, of the Dairy Re-: search Institute at Reading, is rapid and dramatic. A pint of milk left on the doorstep in the usual way. for half-an-hour, ‘and then placed in the larder, bi

loses by the time it is consumed fully | half the vitamin C’ originally delivered by the milkman. There are those who argue that other foods are rich sources of vitamin C, and that these other foods, e.g., green vegetables, cauliflowers,. swedes, oranges, tomatoes, or rose-hip syrup, can furnish us with our daily requirement of vitamin C. But they cannot put up the same argument in the case of riboflavin. A pint of milk supplies the average adult with nearly half the amount of riboflavin needed for good health, and that is one of the reasons why at least a pint of milk per day is advocated. Other foods contribute only small quantities by comparison, exceptions being liver and kidney, which contain it in. abundance. Therefore it is serious matter when milk that’ has been exposed to light for four hours loses 50 per cent. of its riboflavin. When I see milk-carts, uncovered as they usually are, still delivering milk at 11 a.m., I think of the ruination that is being wrought. One remedy is coloured bottles. But will the average housewife be prepared to accept her milk in a brown bottle? Usually, she likes to see the layer of cream on top, and indeed that is one of the reasons why bottles have gained in popularity. Then also, it is easier to detect dirt or see when it has been properly cleansed, if it is of colourless glass. \ Much has been done in U.S.A. on this1 aspect of the protection of milk frém deterioration by agencies such as light and oxygen. We shall probably have to wait till after the war is over before we can implement the progress that has been made along these lines.