Losses in boiling vegetables and the composition and digestibility of potatoes and eggs / by H. Snyder, Almah J. Frisby, and A.P. Bryant.

  • Snyder, Harry, 1867-1927.
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: Losses in boiling vegetables and the composition and digestibility of potatoes and eggs / by H. Snyder, Almah J. Frisby, and A.P. Bryant. Source: Wellcome Collection.

    15/34 (page 13)
    Toss of matter in cooking potatoes—Continued. Method, of preparation and cooking. Weight of potatoes used. Loss of matter in fresh potatoes. Percentage loss of each con¬ stituent. Dry matter. Albuminoid nitrogen. Total nitro¬ gen. 1 Starch. Ash. Dry matter. Albuminoid nitrogen. Total nitro¬ gen. V d -4^ Ash. I G. Skins not removed—Cont’d. Grams. P. ct. P. ct. P. ct. P. ct. P. ct. P. ct. P. ct. P. ct. P. ct. P. ct. Distilled water, liot at start 1, 047 0.15 0. 001 0. 005 0. 05 0.7 0. 5 1.3 5. 4 Do. 1, 075 . 16 . 001 .008 . 04 .7 .5 2. 0 4. 4 Average. . 16 . 001 . 006 . 05 .7 . 5 1 6 4. 9 Alkaline water, hot at start.. 1,229 . 10 trace. . 003 . 03 . 4 . 2 . 8 3. 2 bo... f 034 . 09 trace. . 003 . 02 .4 . 2 .8 2. 2 Average. . 10 trace. . 003 . 03 . 4 . 2 .8 2.7 Limewater, hot at start. 1,075 .04 .001 .002 0.01 .02 .2 .4 .5 0.1 2.2 Do. 848 .06 .001 .003 .01 .02 .3 .5 .8 .1 2.2 Average. .05 .001 .002 .01 .02 .2 . 5 .7 .1 2.2 Average of 6 tests start- ing with hot water ... .4 .4 1.0 .1 3.3 The weight of each ingredient removed divided by the total weight of the same ingredient in the fresh potatoes before cooking gives the percentage of loss of that substance. These figures are shown in the last five columns of the table. The same composition was assumed for the peeled potatoes used in Experiment B as for the whole potatoes used in Experiment 0. This may not be strictly accurate, since it pre¬ supposes the uniform composition of all parts of the potato. As shown on page 27, there is a slight variation between the composition of the interior and the part peeled off, but this jjrobably js not great enough to have a material effect upon the results obtained. DISCUSSION OF RESULTS. By reference to the table (p. 12) it will be seen that, as might be expected, the greatest loss occurs when the potatoes are peeled and soaked in cold water before boiling. In this case the loss of nitroge¬ nous matter was from 46 to 58 per cent, depending upon the length of time they were soaked. Of the albuminoids 25 per cent and of the mineral matters 38 per cent were extracted by the water in which the potatoes were cooked. The water would ordinarily be thrown away and this material lost. When the potatoes are peeled and put into cold water, and heated to boiling as soon as possible, the loss is much smaller, beiug about 16 per cent of the total nitrogenous matter (of which albuminoids form a trifle less than half) and about 19 per cent of the total mineral matter. When the potatoes are peeled and put directly into boiling water the loss of albuminoid and other nitrogenous matter is only about half that of the last case, but the amount of mineral matter is practically