PURE AND IMPURE FOODS. 



" What a Man Eat* He Is." 

 Edited by C. F. Langworthy, Ph. D. 

 Author of 'On Citfaconic, Itaconic and Mesaconic Acids," "Fish as Food," etCi 



THE VALUE OF POTATOES AS FOOD. 



The potato, cailed in different regions 

 white potato, Irish potato, English potato, 

 or round potato, was first introduced Into 

 Europe between 1580 and 1585 by the 

 Spaniards, and afterward by the English 

 about the time of Raleigh's voyages to 

 Virginia. It is commonly believed to be a 

 native of Chile. Wild potato plants close- 

 ly resembling those cultivated today are 

 still found there, though it is a fact worthy 

 of mention that, as the potato has been 

 modified by cultivation, it has, largely lost 

 the power of producing seeds, and the 

 cultivated potato differs from the wild in 

 seldom producing fruits. When first vis- 

 ited by Europeans, the aborigines in Chile 

 and adjacent regions cultivated the potato 

 for its edible tubers and had apparently 

 long done so. It was probably introduced 

 into the United States, especially into Vir- 

 ginia and North Carolina, toward the end 

 of the sixteenth century. It is not surpris- 

 ing that the new food stuff should have 

 grown rapidly into popular favor when we 

 remember its prolific yield, superior keep- 

 ing qualities, ease of propagation, and 

 agreeable flavor. 



The valuable qualities of the potato were 

 speedily recognized, and there are early 

 records of attempts to determine its food 

 value by means of chemical analyses. In 

 1795, Pearson reported "Experiments and 

 observations on the constituent parts of the 

 potato root." Einhof, in 1805, published 

 analyses of the potato, as did also Vau- 

 quelin in 1817. In America, analyses of 

 the potato were reported some 50 years 

 ago by Emmons. These investigations 

 were useful at the time, although they were 

 not made by the methods generally fol- 

 lowed today. This was necessarily the 

 case, as the subiect of the chemistry of 

 nutrition is of comparatively recent 

 growth. In later years many studies of 

 the composition and of the food value of 

 the potato have been made in this and other 

 countries. 



As shown by recent analyses, the skin 

 of the potato constitutes on an average 2.5 

 per cent, of the whole, and the cortical 

 layer 8.5 per cent. It is difficult to peel 

 potatoes so that the skin only is removed. 

 Whether both skin and cortical layer or 

 only the former should be called refuse in 

 our current sense of the word, is perhaps 

 a question. As potatoes are commonly 

 eaten, a good deal of the flesh or edible 

 portion is rejected with the skins. When 



they are baked with the skin on, much of 

 the flesh ,is apt to be thrown away with 

 the skin. When they are boiled with the 

 skin on, the amount of edible portion thus 

 thrown away may be very small. When 

 they are pared for boiling, the amount 

 wasted is likely to be much larger. When 

 they are rough from defects in growth, or 

 from shrinking and shriveling after keep- 

 ing over winter, the amount of flesh cut off 

 in peeling is still larger. Just how much 

 this loss of the edible portion of potatoes 

 will average in ordinary households no one 

 can say exactly. In tables of analyses 

 recently published, the amount of refuse 

 and edible portion rejected with it is esti- 

 mated at 20 per cent, of the whole, and 

 the edible portion left as 80 per cent. 

 Doubtless in many cases the rejected por- 

 tion is much larger. The loss of act- 

 ual nutriment of the potato by the rejec- 

 tion of so much of the edible portion with 

 the skin is a much more important matter 

 from the standpoint of nutritive economy 

 than people generally realize. 



The edible portion is made up on an av- 

 erage of 78.3 per cent, water, 2.2 per cent, 

 protein (total nitrogenous matter), 0.1 per 

 cent, fat, 18.4 per cent, carbohydrates 

 (principally starch), and 1 per cent, ash or 

 mineral matter. Of the carbohydrates, 

 0.4 per cent, is made up of crude fiber and 

 materials which in some of their modifi- 

 cations constitute the cell walls of plants 

 and give them a rigid structure. Though 

 the skin, cortical layer, and flesh differ 

 somewhat in composition, they all resemble 

 more or less closely that of the whole 

 tuber. 



According to statistics obtained in the 

 large number of dietary studies made in 

 this country, potatoes constitute about 13.7 

 per cent, of the total food consumed and 

 furnish not far from 3.9 per cent, of the 

 total protein and 10 per cent, of the total 

 carbohydrates. 



The potato is a staple article of diet in 

 almost every household. The universality 

 and extent of it's consumption would seem 

 sufficient to prove it to be a wholesome 

 and nutritious food. The statement, how- 

 ever, is frequently met in popular articles 

 that potatoes are not wholesome. As 

 far as can be learned, this is purely a 

 gratuitous assumption. While it is pos-. 

 sible there are persons with whom pota- 

 toes do not agree, or who for some rea- 

 sons are compelled to forego starchy foods, 

 there is no reason to suppose that potatoes 



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