July 15,1925 Effect of Dehydration upon Bacterial Flora of Eggs 
161 
RESULTS OF BACTERIOLOGICAL EXAMINATION 
The heat applied to eggs by both processes killed a certain per¬ 
centage of the organisms. This percentage increased as the total 
number increased, and varied with the type of organism. In most 
of the experiments the decrease in the numbers of the colon group was 
very large; the decrease in the numbers of the total lactose fermenters, 
as determined by the plate method, yras decidedly smaller. A com¬ 
parison of the counts on eggs dried by both methods showed that the 
vacuum-drum process is not as efficient as the spray process in kill¬ 
ing bacteria. 
The odor of the dried product was much less pronounced than that 
of the liquid product. Furthermore, the odor was stronger while 
the product was warm from the drier than after it had been cooled. 
Counts of the viable bacteria furnish little basis for estimating the 
quality of such products, especially where the details of their his¬ 
tories are not known. 
EFFECT OF STORAGE 
In order to determine the effect of temperature and time on the 
bacterial count, samples of the various grades of dried egg made by 
the spray process were stored for long periods. 
The samples were placed in glass-stoppered salt-mouth bottles, 
sealed with paraffin, and held at 20° C., at room temperature (approx¬ 
imately 25°) and at 37°. By sealing with paraffin, the factor of 
variable humidity was eliminated. Total counts on plain agar 
incubated at 20° and 37°, total counts and the number of acid 
formers on brom cresol purple lactose agar, and counts of the colon 
group, were made at the beginning, at the end of 3 months, and at 
the end of 10 months. The results are shown in Tables III, IV, and V. 
Table III. — Effect of storage on bacterial counts of dehydrated eggs 
ISamples held in sealed bottles at approximately 25° C. and examined at the dates indicated] « 
Sam¬ 
ple 
Type 
i 
i 
I 
t 
j 
| Quality 
1 
i 
Bacteria on plain 
agar held at— 
Colon 
Bacteria on BCP 
agar 6 held at 20° C. 
for 4 days 
No. 
20° C. for 
4 days 
37° C. for 
2 days 
group 
Total 
Acid 
1 
June 20, 1922 (start): 
Whole__ 
| Good... 
350 
350 
0 
900 
600 
2 
Yolk.... 
1 .do_ 
550 
550 
0 
700 
40 
3 
Whole...— 
Heated.... 
4,900 
1,220 
650 
0 
6,400 
3,500 
350,000 
300 
4 
Yolk.. 
_do.. 
2,950 
58,000 
410,000 
230 
10 
0 
5 
Whole.. 
Rotten_ 
320,000 
740,000 
145 
10 
350,000 
120,000 
0 
6 
Do.. 
_do_ 
0 
680,000 
200 
1 
October 31, 1922: 
Whole__ 
Good__ 
0 
2 
Yolk.. 
_do.. 
350 
135 
0 
470 
0 
3 
Whole... 
Heated_ 
1,900 
2,800 
300 
0 
2,400 
1,900 
51,000 
87,000 
170 
0 
4 
Yolk__ 
_do__ 
95 
0 
0 
5 
Whole_ 
Rotten_ 
55,000 
145,000 
320 
47,000 
101,000 
260 
0 
0 
6 
Do.. 
_do.. 
0 
0 
1 
May 7, 1923 (37° C. for 2 
days): 
Whole.. 
Good__.. 
0 
50 
2 
Yolk__ 
.do.. 
335 
170 
0 
290 
40 
3 
Whole.. 
Heated_ 
930 
210 
0 
210 
30 
4 
Yolk_.. . 
.do__ 
1,250 
135 
0 
120 
10 
5 
Whole.. 
Rotten_ 
36,000 
30,000 
26,000 
0 
29,000 
27,000 
15,000 
6 
Do.. 
I 
.do... 
20,000 
0 
23,000 
« The samples used in this experiment were dried by the spray process. 
6 Brown cresol purple lactose agar. 
