THE EFFICIENCY OF LIME AND WATER GLASS FOR EGG
PRESERVATION
By A. J. MACDONALD and T. S. KRISHNAN, Poultry Research Section, Imperial Veterinary Researoh
Institute, Izatnagar
(Received for publication on 8 February 1943,)
(With Plate XXI and two text figures)
KRISHNAN [1943] demonstrated that indigen-
ous methods employed to preserve eggs for
a few days during the hot weather were of little
value, while some were more harmful than benefi-
cial. Lime is one of the oldest—known egg pre-
servatives. Water glass, though of more recent
origin, has been in use, especially for the domestic
preservation of eggs, in many western countries
for a considerable period. However, there is
very little information available on the efficiency
of these preservatives during the different seasons,
the period for which eggs can be advantageously
preserved in them and the extent of loss in quality
experienced during preservation, particularly
under Indian conditions. The experiments detail-
ed below were carried out to throw light on some
of the above problems.
METHOD
Water glass, lime water and lime and salt
were the materials whose efficiency for egg pre-
servation was studied. The egg preserving
materials were prepared as follows:
Water glass. Syrupy water glass (sodium sili-
cate) was dissolved in nine times its weight of
water and the resulting solution employed for
egg preservation.
Lime water. Freshly slaked lime was mixed
with a large quantity of water to about the con-
sistency of thin whitewash and stirred occasion-
ally for two days. Thereafter, the mixture was
allowed to stand overnight, and the clear supernat-
ant liquid was decanted and used as the preserv-
ing liquid. A pound of quicklime gave about
12 gallons of the preserving liquid.
Lime and salt. One pound of quicklime was
slaked with one pint of boiling water in an earthen
vessel which was kept covered during the pro-
cess. After complete cooling, seven pints of
cold water and four ounces of common salt were
added, the whole thoroughly mixed and allowed
to settle for about a couple of minutes. The
supernatant liquid was poured off and used as
an egg preservative.
Day-old eggs from the Institute flock were
used in these studies. Eggs for preservation were
put into glazed earthen jars, the respective preserv
ing liquid poured in till the level of the liquid was
about three inches above the top of the eggs and
the vessels then covered with lids. The water
lost by evaporation was replaced periodically.
Occasionally a little slaked lime was added to
the lime water and the lime and salt jars to keep
up the lime concentration. Control eggs were
kept in similar unglazed earthen jars. All vessels
containing the experimental eggs, preserved as
well as controls, were stored in the laboratory
under ordinary room conditions.
A daily record of the average temperature and
the relative humidity in the egg storage room
was maintained throughout the experimental
periods. The average daily temperature was
determined by taking the mean of the maxi-
mum and minimum temperatures registered every
24 hours. Normally the difference between the
maximum and minimum temperature recorded
for any one day did not exceed 4-5ºF.
An experiment to compare lime water with
lime and salt was started on 12 December
1940 and concluded after 20 weeks on 1 May
1941. Another experiment to compare lime
water with water glass was begun on 21 May
1941 and ended after 11 weeks on 7 August
1941. For the sake of convenience, the former
study is hereafter referred to as the 'winter test'
and the latter as the 'summer test'.
For the winter test three similar groups, each
of 80 eggs, containing equal numbers of fertiles
and infertiles was selected. One lot was kept
as controls, another preserved in lime water
and the third in lime and salt. Six day-old
eggs were analysed at the commencement of
the experiment for their initial quality. Lots of
six comparable eggs from each of the control,
lime water and lime and salt groups were removed
at fortnightly intervals and examined for their
internal quality.
In the summer test, two comparable groups,
each of 165 eggs, were selected. Each group con-
tained equal numbers of fertiles and infertiles.
One group was preserved in lime water and the
other in water glass. Another group of 45 eggs
was kept as control. Since previous experience
had shown that control eggs could not,
at this season, last for more than two or three
weeks, without spoiling, the examination of
these eggs was restricted to three weeks. For
the determination of initial quality, 12 day-
old eggs were broken and measurements made
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