Common Foodstuffs Research Articles

War-time Growth of Schoolboys

THE rationing and restriction of many of our common foodstuffs has prevented the free choice of food to which we were all of us accustomed before the War, but it has handicapped some of the community much more than others. The public schools have had a difficult time because boys of 14-18 require more total food than the average holder of a ration book, yet the schools have no means of obtaining meals for their boys outside the ordinary rations. The question therefore has arisen as to whether this has made any difference to the boys' rate of growth. Are public school boys now as tall and heavy as they were before the War? The pre-war and war-time weight and height records of boys at two public schools have been submitted to statistical analysis. Both schools take a serious interest in the way their boys are fed.

ASCORBIC ACID IN DEHYDRATED FOODS

THERE is much evidence that titration against 2,6-dichlorophenolindophenol, provided it is done rapidly and in acid solution1, gives results accurately agreeing with the biological estimate of ascorbic acid in common foodstuffs, including fruits and vegetables (both raw and as generally cooked), and in various animal tissues2. Even for most manufactured articles, such as jams, tinned fruits and various other processed foods, the chemical test has been shown to be generally applicable2. In a few exceptional instances, however, interferences from non-specific reductants may have to be allowed for. Such substances occur in caramelized and fermented products (for example, in malt extracts, or the products obtained by alkaline-heat treatment Of sugars, in materials such as oats or pea mush after heat treatment, and in yeast and fermented juices)3. The substances known to interfere include stannous and ferrous salts, as well as sulphites, sulphides and thiosulphates, among inorganic substances, and re-ductones and reductic acid among organic compounds. Substances of the former class, however, are not normally present in foodstuffs, and moreover they can be fairly easily differentiated if desired. Thus, thiosulphate and sulphydryl compounds may be removed by precipitation with mercuric acetate4, sulphite by treatment with acetone5, or sulphides by conversion to hydrogen sulphide and removal in vacua. Lugg' has recently recommended the use of formaldehyde to differentiate ascorbic acid from sulphides, sulphites, thiosulphates, quinones, sulphydryl compounds and reductones. It will be recalled that glutathione does not interfere under the conditions of the test', and that free cysteine is not normally a constituent of foodstuffs and in any event reacts so much more slowly that its presence would not be a source of serious error.

“Vegetables as Food”

IN a recent article in NATURE1, it is stated that there is less carotene (provitamin A) in carrots than in spinach, watercress or broccoli. It would be dangerous to allow this statement to pass unchallenged. In reality, as was pointed out in a recent review in these columns2, the carrot stands preeminent as a source of provitamin A. It is the only common foodstuff in Great Britain continuously available throughout the year, a single daily helping of which will supply the full requirement for vitamin A. It is unfortunate, therefore, that doubt should have been cast on this unique virtue of the carrot.

Malnutrition in South Africa

AN informative survey of the state of nutrition of the peoples of South Africa is given by Ellen Radloff and T. W. B. Osborn in a pamphlet with the above title (Johannesburg: The Witwatersrand University Press, 1939. 2s.). South Africa has been spoken of as the most prosperous country in the world, which is a true statement for a minority of the European section. But South Africa is also a country of poor whites and poorer blacks, which is true for several millions of non-Europeans and several hundred thousands of Europeans. The principal dietary essentials for proper nutrition are discussed, with descriptions of the conditions that result when these are deficient. Tables are given of the vitamin content of common foodstuffs and of typical South African diets.

Sulfur in Eggs

Abstract STUDENTS of nutrition are vitally concerned in the role of sulfur in metabolism. The sulfhydryl compounds play a major part in cell oxidation and reduction, cell growth, and in the function of active enzymes. Cystine is known to exist in large quantities in hair and in other body parts. Its presence in food of sheep in adequate quantity is known to influence the quality and yield of wool. Both cystine and methionine are listed among the essential amino acids, the addition of either being sufficient to supplement a diet adequate in other respects. In view of the importance of cystine and methionine in nutrition, it seems desirable to know their amounts in common foodstuffs, especially in one as widely used as eggs. Osborne (1902) pointed out that not all the sulfur in proteins could be accounted for as cysteine and cystine. In 1923 Mueller isolated from casein a new thiol . . .

The vitamin A requirement of swine

The present paper reports the results of experiments which were carried out to obtain information on the types and amounts of the common foodstuffs which should be included in a ration for the prevention of avitaminosis A in swine. The actual vitamin A requirement of swine in terms of carotene was also investigated. Ten different diets were used and three animals were placed on each. Seven of these diets produced the classical symptoms of avitaminosis A in the animals, two contained minimal or just subminimal amounts of the vitamin, while one appeared to permit storage. The rations on which the symptoms of avitaminosis A did not appear included maize meal and alfalfa meal. Both these foodstuffs, however, have been shown to produce undesirable effects in the animals at the levels at which they must be fed to prevent the onset of the disease symptoms.