Experimental cookery

Potato chips. The most important factor in making potato chips ap- pears to be the sugar content of the potato. With a high sugar content the chips become too brown, with production of a more or less disagreeable astringent flavor, before they are suflSciently cooked. The concentration of sugar increases in potatoes stored at a low temperature. At ordinary tem- peratures the sugar is used up in respiration ; at lower temperatures metab- olism is retarded but sugar production by enzymes proceeds, so that sugar accumulates. COOKING OF DRIED LEGUMES 135 Peacock and Brunstetter have reported a very simple test for predeter- mining the cooking value of potatoes because of accumulated sugars. One cubic centimeter of a saturated aqueous solution of picric acid and 1 cubic centimeter of a 20-per cent sodium carbonate solution are placed in a test tube. To this is added a piece of potato of definite length cut with a cork borer. The solution is heated carefully to prevent boiling over for 1 minute. If the solution does not become much darker it indicates that the potato has little sugar and is suitable for both chips and "French fries." With increasing sugar content the solution becomes darker and darker when time of heating and size of piece of potato are kept stand- ardized. The darkest shade given by Peacock and Brunstetter is a dark garnet-brown; but Swalley tested some potatoes that gave shades two degrees darker in color than dark garnet-brown, the darkest being nearly black. Potato slices fried for a definite time in fat at a definite tempera- ture become browner and browner as the sugar content increases and give perfect correlations with the picric acid test. In general Swalley found that the longer the potatoes were stored at 32°F. (storage was from 11-14 to 12-15), the longer the time required for storage at room tempera- ture (those stored at 32° for 31 days required 45 days at room tempera- ture) before good chips were obtained. Wright et al. found that potatoes stored at 32° and 36° were not suitable for French fries, as they browned too quickly and had a burned flavor. To some extent this was also true of potatoes stored at 40°. As the storage temperature increased the time necessary for cooking increased. Potatoes stored at 60° and 70° gave fries of attractive golden-brown color, mealy texture, and good flavor. Similar results were obtained with chips. Preparation o£ chips. Because it is difficult or impossible to slice the potatoes evenly by hand, they should be cut with a slicer. If salt is added to the soaking water the slices are partially dehydrated during the soak- ing; thus a shorter time is required for cooking and no addition of salt is necessary after cooking. For %. pound of potato and J4 cup of water about 8 grams of salt are required. Cooking chips. The cooking time and temperature are dependent to a certain extent on the quantity of potatoes added to a given amount of fat. For % pound of slices about 3 minutes are required when the initial temperature of the fat is 190°C. and the quantity of fat is about 2 to 2^ pounds. Smaller quantities of potatoes cook in a shorter time. The chips are done when bubbling of the fat ceases, which indicates the major portion of the water has evaporated. Cooking of Dried Legumes