ASCORBIC ACID, THIAMIN, RIBOFLAVIN, AND NIACIN CONTENT OF POTATOES IN LARGE‐SCALE FOOD SERVICE ¹

Abstract

The purpose of this study was to determine the content of ascorbic acid, thiamin, riboflavin, and niacin in potatoes as they were peeled, soaked, steamed. mashed, and held for serving in the Navy mess hall on the Cornell University campus, where 2,800 Navy personnel were served. Samples for analyses were taken from the potatoes a t various stages during the regular methods of preparation in use a t the mess hall. No attempt to change these methods was made, except f o r the addition of salt to the soaking water of some of the potatoes. EXPERIMENTAL PROCEDUREThe potatoes used in the first four, and in the sixth, eighth, and ninth studies were U. S. No. 1 grade, Epma brand, from Rocomoke, Md. j those in the fifth and seventh studies were also U. S. No. 1 grade but were from John Richter, Duncannon, Pa. The variety of the potatoes and the storage conditions before they were delivered were unknown. At the Navy mess hall the potatoes were stored in the shipping sacks a t room temperature.Preparation Methods : The potatoes were peeled in an institution-type potato peeler and were then held in cold water for 0 to 60 minutes before they were eyed. About 45 pounds of potatoes were drained a t one time, placed on a table, and eyed by hand with a small knife. As each potato was eyed it was dropped into water [20 to 23"C.(68 to 73.4"F.)] in 31-galIon galvanized iron cans and soaked for 0 to 28.5 hours (Table 1). I n Study 6 the potatoes, immediately after being eyed, were cut in large cubes (about two inches) for creaming; in each of the other studies they were left whole.The soaked potatoes were drained, placed in perforated steamer pans 21 b y 19.5 by 8.5 inches, each holding about 30 pounds, and steamed in an institution-type steamer which registered five pounds pressure.I n Studies 2, 3, and 7 the steamed potatoes were mashed. These potatoes, in about 60-pound lots (the contents of two steamer pans), were put into the bowl of a mechanical mixer as soon as they were removed from the steamer. Both the bowl and the beater were of heavy aluminum. About 1.5 pounds of fat (butter in Studies 2 and 3 and margarine in Study 7) and one-half cup of salt were added and the potatoes were mixed on low speed for about one minute. Then hot milk (exact amount could not be The work described in this paper was done under a contract, recommended by the Committee on Medical Research, between the Office of Scientific Research and Development and Cornell University. 461 FOOD RESEARCH, VOL. 11, KO. 6.