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A Study on the Potential Mutagenicity of Overcooked Hardboiled Eggs using Allium
cepa test
Russel Christine B. CorcinoGermaine D. Arda
Background of the Study
Eggs Major part of the daily diet of humans Can be cooked in different ways (ex. Boiling) People may sometimes overcook eggs
Generates hydrogen sulfide (H2S) harmful to the bodyCoagulates the structure of the egg
People still consume overcooked eggs
Statement of the Problems1. How long is the normal cooking time of an egg to
be considered?2. Is there a difference in the physical characteristics
of an overcooked hardboiled egg and a normal cooked hardboiled egg?
3. Is there a significant difference on the mitotic index among the overcooked hardboiled eggs and normal cooked hardboiled egg?
4. Is there a significant difference between the mitotic indexes of overcooked eggs cooked in different time intervals?
Scope and Limitations• Boiling is the method used in cooking the eggs• Three time intervals (including the normal
cooking time)• Positive and negative controls for comparison• Allium cepa test is used (microscopic analysis
only)• No chemical analysis made• Study is conducted at MSU-IIT IDS Chemistry
Laboratory II
General Procedure
TREATMENT DESCRIPTION
A Cooked at normal cooking time
B Cooked 2 minutes beyond normal cooking time
C Cooked 5 minutes beyond normal cooking time
SAMPLE DESCRIPTION
A Exposed to Treatment A
B Exposed to Treatment B
C Exposed to Treatment C
Positive Control exposed to 0.05% colchicine
Negative Control exposed to distilled water
Table 1. Treatments Done to the Hardboiled Egg
Table 2. List of the Different Sample of Roots
Allium cepa test1. Distilled water2. Treatment solution (45 minutes)
exposure to the treatment
3. Distilled water4. Fixative solution (30 minutes)
“freeze” the cells
5. Distilled water6. 1 M HCl and left (10-12 minutes)
to soften the root tip
7. Distilled water.
Results of the Experiment
A. Normal Cooking time: 15 minutesB. Physical Characteristics (Overcooked vs.
Normal)
A B C
(a)Normal-cooked egg, (b) Egg cooked 2 mins. beyond normal, (c) Egg cooked 5 mins.beyond normal
Series130.00000
35.00000
40.00000
45.00000
50.00000
55.00000
60.00000
65.00000
70.00000
75.00000
80.00000
Positive ControlNegativeControl Sample A Sample B Sample C
Replicate 1Replicate 2Replicate 3
Treatments
Mito
tic in
dex
(%)
Fig. 1. Mitotic Indices of the Onion Roots Exposed to the Different Treatments
C. Microscopic Analysis
Can be caused by CARCINOGENICITY,
which is a type of MUTAGENICITY
Fig 2. Normal Mitosis of Allium cepa roots (from the left: Interphase, Prophase,Metaphase, Anaphase, Telophase) (Huss, 2007)
Fig. 3. Chromosomal aberrations detected in Replicate 2 exposed to treatment B:(A) chromosomal bridging during early anaphase, (B) chromosomal stickiness.
Hypothesis Testing (One-way ANOVA)
Ho : μ1 = μ2 = μ3 = μ4 = μ5
H1 : at least one differ from the others
α = 0.05 (level of significance)
Table 3. Basis for Groups for ANOVA and Post hoc Analysis
Group # Treatment
1 Positive Control
2 Negative Control
3 Treatment A
4 Treatment B
5 Treatment C
Reject Ho since p-value=0.0003 is less than α = 0.05.Proceed to Post hoc Analysis!
Table 4. ANOVA table
Source SS df MS F p-value
Treatment 2,385.261840 4 596.3154600 15.19 .0003
Error 392.481336 10 39.2481336
Total 2,777.743176 14
Table 5: Post hoc Analysis: p-values for pairwise t-tests
Group # Group 2 Group 3 Group 1 Group 5 Group 4
Mean 31.89135 35.35431 44.69884 59.78601 63.19930
Group 2 31.89135
Group 3 35.35431 .5138
Group 1 44.69884 .0312 .0977
Group 5 59.78601 .0003 .0007 .0145
Group 4 63.19930 .0001 .0003 .0047 .5197
Treatment A vs. Controls
• Group 3 has no significant difference with group 2 since their p-value is equal to 0.5138 which is greater than α= 0.05.
• Group 3 has no significant difference with group 1 since their p-value is equal to 0.0977 which is greater than α= 0.05.
μ1 = μ3
μ2 = μ3
Treatment B vs. Controls
• Group 4 has a significant difference with group 2 since their p-value is equal to 0.0001 which is less than α= 0.05.
• Group 4 has a significant difference with group 1 since their p-value is equal to 0.0047 which is less than α= 0.05.
μ1 ≠ μ4
μ2 ≠ μ4
Treatment C vs. Controls
• Group 5 has a significant difference with group 2 since their p-value is equal to 0.0003 which is less than α= 0.05.
• Group 5 has a significant difference with group 1 since their p-value is equal to 0.0145 which is less than α= 0.05.
μ1 ≠ μ5
μ2 ≠ μ5
Treatment A vs. Treatment B and Treatment C
• Group 3 has a significant difference with group 4 since their p-value= 0.0003 is less than α= 0.05.
• Group 3 also has a significant difference with group 5 since their p-value= 0.0007 is less than α= 0.05.
μ3 ≠ μ4
μ3 ≠ μ5
Treatment B vs. Treatment C
• Group 4 has no significant difference with group 5 since their p-value is equal to 0.5197 which is greater than α= 0.05.
μ4 = μ5
Summarizing the Results
μpositive = μA μnegative = μA
μpositive ≠ μB μnegative ≠ μB
μpositive ≠ μC μnegative ≠ μC
μA ≠ μB μA ≠ μC μB = μC
Conclusions1. The normal cooking time to be considered for
hardboiled eggs is 15 minutes.2. There is a difference on the physical characteristics
among the normal cooked hardboiled eggs and overcooked hardboiled eggs.
3. There is a significant difference between the mitotic indices in the roots of the Allium cepa exposed to normal cooked hardboiled egg and overcooked hardboiled egg.
4. There is no significant difference between the mitotic indices in the roots of the Allium cepa exposed to overcooked egg cooked at different time intervals.
Recommendations
The researchers recommend the ff:• To do more study about this research using
other mutagenicity tests like Drosophila, etc.• To test the possible effects of raw eggs to the
cells.• To test other variety of egg samples such as
ducks, birds and native chicken.
THE END