310 Efficiency of Lime and Water Glass for Egg Preservation
the yolk index figures remained fairly steady
at about 0.175 and in the latter at about 0.190
during the next five weeks.
(c) Percentage thick white
Table IV gives a record of the thick white per-
centages for the control and preserved eggs
during the winter and summer trials. In the
winter experiment, there was a continuous drop
in the percentage thick white of the control
eggs, from an initial 62.2 to 19.4 at the end
of 14 weeks; thereafter, no measurements could
be made as the albumen could not be separated
from the yolk owing to rupture of the yolk sac.
In the lime and salt group, the percentage thick
white figure declined to 47.7 at six weeks. Sub-
sequently, there was a slight rise in the next
four weeks to 55.5, and thereafter it declined
to 41.0 at 18 weeks. Among those preserved in
lime water, there was a slight rise from 62.2
to 63.7 in the first fortnight and after that a
fairly continuous decline to 42.5 at the end of
18 weeks. However, the general uniformity of
decrease of this factor was departed from in two
instances. At eight and sixteen weeks, the figures
recorded were higher than those obtained
at four and fourteen weeks. No figures have
been recorded for either preservative for
20 weeks, as most of the yolks broke on opening
out the eggs.
TABLE IV
Changes in percentage thick white due to storage
Winter test
Period of storage
Initial quality . .
2 weeks . . .
4 „ . . .
6 „
. . .
8 „
. . .
10 „
. . .
12 „
. . .
14
„
.
.
.
16 „
.
.
.
18
„
.
.
.
20 „ . . .
Percentage thick white
Controls
62.2
60.1
54.7
47.0
32.1
28.2
15.4
19.4
. .
. .
. .
Stored
in lime
and salt
62.2
59.9
55.6
47.7
51.7
55.5
52.1
49.7
48.6
41.0
. .
Stored
in lime
water
62.2
63.7
58.5
49.2
52.7
48.3
49.3
45.8
51.6
42.5
. .
Summer test
Period of storage
Initial quality . .
1 week . .
2 weeks . . .
3 „
. . .
4 „
. . .
5 „
. . .
6 „
. . .
7 „
. . .
8 „
. . .
9 „
. . .
10
„
.
.
.
11
„
.
..
Percentage thick white
Controls
50.8
50.9
31.9
. .
..
..
..
..
. .
..
..
..
Stored
in water
glass
50.8
50.2
51.1
46.9
43.4
37.7
35.0
37.3
32.7
34.4
32.2
..
Stored
in lime
water
50.8
48.3
47.8
43.0
41.8
43.6
36.4
35.7
37.5
40.3
34.9
30.1
The initial quality of the thick white in the.
summer eggs was lower than that of those used in
the winter experiment, the respective figures being
50.8 and 62.2 per cent. The percentage thick
white of the control eggs was practically un-
altered at one week, but declined to 31.9 at
two weeks. Thereafter, owing to rapid deterio-
ration in quality, no average figures were obtain-
able. In this experiment, the percentage thick
white of the eggs preserved in water glass re-
mained fairly steady for the first fortnight and
then declined fairly steadily to 32.2 at 10 weeks.
When the experiment was concluded at 11 weeks,
hardly an egg of this group had the yolk un-
broken when opened out for quality measure-
ment. With eggs preserved in lime water, there
was a fairly steady fall in the percentage thick
white from the initial figure of 50.8 to 30.1
at the end of the test,
There were minor departures from a steady and
even weekly decline in the different groups of
preserved eggs, both in the winter and the
summer experiments. These fluctuations are
somewhat similar to those already noticed in
the albumen index and both may be attributed
to experimental error caused by the rather
large individual variations in quality. Differ-
ences in the keeping quality of eggs from differ-
ent individuals might also have contributed to
increasing the range of fluctuations.
(d) Air-ell size
The changes noticed in the depth of the air cell
in the control and the preserved eggs at the
periodical examinations during storage are
presented in Table V.