30
An Egg-cooling Cabidet
averaging the morning and evening readings. The
maximum daily temperatures recorded in the room
ranged from 94° to 102°F. in Test 1, 98° to 106°F. in
Test 2 and 100° to 110° F. in Test 3. The average
room temperatures for each of the tests were 93.1°,
97.3° and 100.3°F., in Tests 1 to 3 respectively.
The corresponding temperatures inside the cooler
were 76.7°, 80.2° and 78.7°F. respectively. Mean
relative humidity percentages in the room in Tests
1 to 3 were 34, 36 and 23; the corresponding figures
in the cabinet were 65, 67 and 63 respectively.
In all the three experiments the cabinet tempera-
tures were much lower than those recorded for the
room. In Test 3 the average drop in temperature
was greater than in Tests 1 and 2 owing to the
higher room temperature and lower humidity,
both factors being more favourable for the efficient
working of the cooler. A maximum drop in
temperature of 36°F. was recorded during a period
of strong hot winds when the room temperature
was 110°F. and the relative humidity below 5 per
cent. Thompson and Roberts [1940] obtained a
maximum drop of 24°F. with a temperature of
103°F. and a relative humidity of 9 per cent.
In preliminary experiments it was found that
the conditions of fairly high temperature and
humidity inside the cabinet favoured mould growth
in eggs stored for more than ten days. In a
number of experiments it was found that whilst
all the eggs remained apparently free from mould
during the first 10 days of storage, further storage
for four to five days resulted in nearly all of them
developing mould growths. This defect in storage
under cabinet conditions was overcome by trans-
ferring the eggs into a perfectly fresh cabinet after
one week's storage. The cabinet after use for one
week was thoroughly washed and left to stand in the
sun for a period of three to four hours and rested
until required again for use at the end of a week.
With two cabinets, one in use for one week and
the other rested after cleaning for one week, no
trouble was experienced with mould growths in
various tests involving storage for four weeks in
the cabinets.
EMBRYO DEVELOPMENT
A total of 240 fertile eggs were used to test out
the efficiency of the egg cabinet in retarding
embryo development. The maximum daily room
temperatures recorded during the storage period
ranged from 103° to 110°F. Hour-old eggs and day-
old eggs that had been stored at room temperature
were used and stored either in the cooler or in the
room. The hour-old eggs would normally only
be available with the producer who collects the
eggs every hour. The day-old eggs represent the
very best quality eggs as received by the retailer
or consumer. The details of the tests carried out
at different stages are given in Table I.
TABLE I
Embryo development
Period
of
storage
Fresh
3 days
7 days
10 days
14 days.
Hour-old eggs
stored in
Coolor
..
..
..
..*
..*
Room
..
+
+ + + +
+ + + +
+ + + +
Day-old eggs
stored in
Cooler
+
+
+ +
+ +
+ +
Room
+
+ + +
+ + + +
+ + + +
+ + + +
Remarks
No. 35
No. 35
No. 35
No. 35
No. 35
+ Development without blood, visible clearly
on candling.
+ +Development with trace of blood, visible
only on opening out.
+ + + Further development with blood veins
clearly visible on candling.
+ + + +Extensive development.
*Slight germ development without blood, visible
only on opening out.
Hour-old eggs stored at room temperature for
three days were classified as edible. They showed
prominent embryo development but no blood
under the candling lamp. Hour-old eggs stored
at room temperature for seven days or more
were judged as inedible on account of extensive
embryo development.
Under the cabinet condition of storage the eggs
showed no signs of embryo development under
the candling lamp at 10 and 14 days. However,
at 10 and 14 days about 50 per cent of the eggs
when broken showed very slight embryo develop-
ment. The embryo development in eggs stored
for 14 days in the cabinet was much less than that
of similar eggs stored for three days at room
temperature.
The day-old eggs stored at room temperature
showed a certain amount of embryo development
under the candling lamp but no blood was visible.
The eggs when stored at room temperature for a
further period of three days showed marked embryo
and blood development under the candling lamp.
These eggs were classified as inedible. At each
of the subsequent stages of holding at room tem-
perature the quality was somewhat poorer than
the corresponding hour-old eggs stored under the
same conditions. The day-old eggs stored in the
cabinet for three days showed slightly greater em-
bryo development than at a day-old but were still
edible as no blood had formed. After 7, 10 and
14 days in the cabinet the day-old eggs showed
slightly more marked development of the embryo
under the candling lamp than at three days but
no blood was visible. However, at all these three
later stages the broken out eggs had very minute