Fjölrit RALA - 22.03.1979, Blaðsíða 70

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I. Older Icelandic Studies
Unfortunately, research on the nutritional value of
potatoes in Iceland has not been what it should be in the
last decades. Actually, no research has been done since
a report by Sigurjónsson on the vitamin C content of pota-
toes was published in 1957.
The main studies carried out before this time were
measurements on the dry matter, nitrogen compounds, fat,
ash and starch content of 15 varieties of potatoes by
Vestdal in 1937-38. Two years later (1940), the same
factors were measured in 5 varieties by ólafsson. At
the same tirae, the thiamine content of several foods,
including potatoes, was measured by Tómasson.
A few years later (1948), extensive experiments
were commenced under the supervision of Friðriksson
and they were concluded in 1953. In these experiments
142 potato varieties were compared. The dry matter con-
tent was measured in these varieties and the starch con-
tent later calculated using a special balance. The bal-
ance is based on the assumption that a specific relation-
ship exists between the volume and starch content of
potatoes.
II. Variations in the Nutritional Values of Potatoes
The nutrient content of potatoes depends on many
factors including the variety used, climate, soil, ferti-
lizer (type and magnitude), storage conditions and storage
time.
Nutrient tables usually consist of annual averages
where the total consumption of the various varieties as
well as changes in the nutrient levels on storage, are
taken into account. If nutrient tables published in Ice-
land (Sigurjónsson 1963), Sweden (Ernst Abramson 1974),
England (R.A. McCane and E.M. Widdowson 1969) and the
U.S.A. (Bernice K. Watt et al. 1975) are compared, it can
be seen that there is a considerable difference in the
amount of the individual nutrients in uncooked potatoes
depending on the table. See table 1.