CHEMICAL PROPERTIES OF THE POTATO

Northern Advocate, 25 November 1925, Page 12

CHEMICAL PROPERTIES OF THE POTATO

It is the impression generally that the potato is simply a useful vegetable, well suited to be boiled, baked, or mashed; but beyond that its properties and uses arc little, if at all, known, certainly not amongst the so-called public, and it is only within recent years that any use whatever was made of it a-s an article of manufacture. In the year 1834 the article of farina starch, for dressing muslins, was first manufactured from it. Beyond this, and its sale as household starch —and not a little as "Indian arrowroot," its produce, is, in fact, unknown to the commerce of this country. Abroad it is not so. After extracting the farina, the pulp is manufactured into ornamental articles, such as picture-frames, snuff-boxes, and several descriptions of toys, and the water that runs from it in the process of manufacture is a most valuable scourer. For perfectly cleansing woollens and such-like articles it is the housewife's panacea. Yet it is beyond all dispute that, up to the period of the potato blight, the Irish cottier peasants, amounting to perhaps one-half of the whole population, lived to a good old age, and reared large families, fed upon the potato alone. . The natural inquiry that strikes the mind is, what are the constituents of th? potato to produce such results? It is a fact that the potato contains some 75_ per cent of water; but what does the residue contain? What are the actual nutritive components? They are as follow: —

Per cent. Of starch 84.077 Of gluten 14.818 Of oil 1.104 And what are the nutritive constituents of wheat? Per cent. Of starch 78.199 Of gluten 17.536 Of oil 4.265

Thus we find that the essential elements of nutrition are identical in the potato and wheat, whilst the small deficiency of gluten and oil (bone-and-sinew producing matter) is compensated by the increase of starch (flesh-and-fat producing matter). And it is unquestionable that the oil and gluten of wheat rest principally in that part of the grain which is not used for human food, viz., the bran and pollards; whilst the entire dry matter of the potato is suited for conversion into food of several kinds. With such facts to guide us, is it not reasonable to inquire, "Why should the potato be used merely as a garden vegetable? Why is it not converted into an article of commerce, as meal and flour, of wheat, oats, etc.?" But the question in reality is, not the quantum of food to be found in a given weight of potatoes, as compared with a given quantity of wheat; it is the quantum capable of being produced from a given quantity of land. All the arguments used to abolish the cultivation of the potato have been founded on this misconception. It has been designated the "root of evil," gravely declared by authority to have "little or no nutrition as compared with grain"; has been "the most wasteful crop and j the least desirable food," all because it I contains 75 per cent of water, which has i in reality nothing to do with the question of the quantum and quality of the nutriment to be obtained by its cultivation. Cultivate an acre of land with potatoes, and a similar quantity with wheat, and convert the produce from each into dry matter. Then taking the lowest average production of the potato, and the general average of wheat, the result will | be found as follows:— The dry matter of the potato will give a total of 40761b per acre, whilst the dry matter of wheat will give but 10551b per acre. There will be found in the produce of the potato, 34271b per acre; wheat, 8251b per acre. The potato, 6041b gluten; wheat, 1851b gluten. The potato, 541b oil; wheat, the same. Thus the actual quantity of food to be produced from an acre of land culti- I vated with potatoes is nearly four times j the quantity from an acre cultivated with wheat, and the quantum of nutri- ' tion in the dry matter of potato, weight, for weight with wheat, is almost alike. ,