Árbók Háskóla Íslands - 02.01.1955, Síða 69

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of berries picked after night frost showed conspicuously low
values.
Milk. As shown in table 10 the average for 91 samples of
pasteurized milk (market milk) was 1.08 mg/100 ml. In summer
the values were slightly higher than in winter time, but the dif-
ference was not statistically significant. Four samples of raw
milk (6-8 hrs. old) provided an average of 1.85 mg (1.69-2.06
mg). On standing at room temperature the loss was distinctly
greater in raw than pasteurized milk.
Meat, liver, blood, etc. Table 11. The sheep blood was obtained
from a slaughterhouse and some loss may have occurred during
the process of defibrination. The cow blood was taken directly
from a vein. In two samples of roes (cod) 26.4 and 24.5 mg
were found.
PART II
Preservation and cooking.
Freezing. Table 12 shows the values for deep-frozen vege-
tables. There is an appreciable loss of ascorbic acid involved in
the process, but further fall during storage is often low. In some
cases it was suspected that the pre-heating, to inactivate oxid-
izing enzymes, had not been effectively carried out.
Canning (domestic processed). Samples of vegetables exa-
mined after several months’ storage often had retained about
30% and a similar amount was found in the canning liquid.
Domestic preserving. Several products (juice from berries,
syrups, jams, etc.) were tested, with varying results (p. 39^40).
Cooking. The loss on cooking potatoes and swedes in the ordi-
nary way was on the average about 15% (tables 13 and 14).
The waste was about 6% and 25% for potatoes and swedes re-
spectively. For green vegetables the cooking loss was much
greater, up to one third in the case of cauliflower, 40—50% for
cabbage and still more for kale (table 15), the content in the
cooking water not being taken into the account. When steamed