A Study on the Potential Mutagenicity of Overcooked Hardboiled Eggs using Allium

cepa test

Russel Christine B. CorcinoGermaine D. Arda

Background of the StudyEggs 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 treatment3. Distilled water4. Fixative solution (30 minutes)

“freeze” the cells5. Distilled water6. 1 M HCl and left (10-12 minutes)

to soften the root tip7. 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 othersα = 0.05 (level of significance)

Table 3. Basis for Groups for ANOVA and Post hoc Analysis

Group # Treatment1 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