Follow-Up Experiment by Chan Ka Man (3035574543)
Follow-Up Experiment - How to achieve optimal stability of the vinaigrette using different stabilizers
Before cooking
What ingredients and equipment needed?
- 100 ml of Cooking Oil
- 300 ml of Grape Vinegar
- 7.5 ml of Honey
- 1 Egg yolk
- 3 glass containers with lid
- Measuring cup
- Measuring spoon
- Calliper
- Computer with photo-editing software (e.g. Photoshop)
Who does the shopping?
Me and my mother.
Me and my mother.
Where to obtain ingredients/equipment/tools?
There are all obtained from my home.
There are all obtained from my home.
Where do I cook?
In my home, mainly in the dining room.
In my home, mainly in the dining room.
Objective:
To find out the effects of different stabilizers and the outcome when adding both an emulsifier (a kind of stabilizer) and a stabilizer does not have any emulsifying ability into the vinaigrette, thus find out the stabilizer or combination of stabilizers that can let the vinaigrette achieve optimal stability.
Why is this investigation important?
From the first experiment, it could be concluded that there exist multiple different kinds of stabilizers, each with unique functions. This could explain why many products in the market contain more than one kind of stabilizer. This investigation aims to compare the stabilizers' effects and check if using more than one kind of stabilizer could really increase the stability of vinaigrette. The results can help us use stabilizers more flexibly when preparing vinaigrettes in the future.
Why these ingredients?
Honey: From the first experiment, it was found out that it is a relatively strong stabilizer that can prevent oil droplets from merging with each other. I aim to find out the effects when using it with egg yolk, and see if they can achieve higher stability when used together compared to when using them separately.
Egg yolk: It is a very common emulsifier, and is often treated as one of the strongest emulsifiers. It is used to create an emulsion in the vinaigrette.
Why vote out some ingredients?
Salt and pepper: Vinaigrette usually contains salt and pepper as seasonings. However, they are not necessary, so in order to keep the experiment simple, and to better control the experiment, they are voted out.
Mustard: Mustard is a very common emulsifier. However, since it is hard to obtain during this time, and it does not go very well with the recipe of grape vinaigrette, it is voted out.
Cheese: From the first experiment, it was found out that cheese is not a strong stabilizer, nor it has emulsifying ability, thus it is not desirable to use it in this experiment. Also, at the end of the first experiment, the vinaigrette with added cheese decolourized from unknown reasons, which can affect the accuracy of the result. Furthermore, since the cheese needs to be molten in order for it to have a stabilizing effect in the vinaigrette, it makes it hard to control the temperature of all samples, which could affect the results. Therefore, it is voted out.
Why a computer with photo-editing software is used?
From the first experiment, it was found out that it was not very practically feasible, as it is very hard to accurately measure average diameter of oil droplets even when very accurate measuring tools (calliper with a scale of as small as 0.02mm). To improve, I have decided to take pictures of the oil layers and calculate the average diameter of oil droplets by the assistance of photo-editing software. I think this can let me get more accurate data.
Hypothesis:
The vinaigrette achieves optimal stability when both egg yolk and honey are added into it.
To find out the effects of different stabilizers and the outcome when adding both an emulsifier (a kind of stabilizer) and a stabilizer does not have any emulsifying ability into the vinaigrette, thus find out the stabilizer or combination of stabilizers that can let the vinaigrette achieve optimal stability.
Why is this investigation important?
From the first experiment, it could be concluded that there exist multiple different kinds of stabilizers, each with unique functions. This could explain why many products in the market contain more than one kind of stabilizer. This investigation aims to compare the stabilizers' effects and check if using more than one kind of stabilizer could really increase the stability of vinaigrette. The results can help us use stabilizers more flexibly when preparing vinaigrettes in the future.
Why these ingredients?
Honey: From the first experiment, it was found out that it is a relatively strong stabilizer that can prevent oil droplets from merging with each other. I aim to find out the effects when using it with egg yolk, and see if they can achieve higher stability when used together compared to when using them separately.
Egg yolk: It is a very common emulsifier, and is often treated as one of the strongest emulsifiers. It is used to create an emulsion in the vinaigrette.
Why vote out some ingredients?
Salt and pepper: Vinaigrette usually contains salt and pepper as seasonings. However, they are not necessary, so in order to keep the experiment simple, and to better control the experiment, they are voted out.
Mustard: Mustard is a very common emulsifier. However, since it is hard to obtain during this time, and it does not go very well with the recipe of grape vinaigrette, it is voted out.
Cheese: From the first experiment, it was found out that cheese is not a strong stabilizer, nor it has emulsifying ability, thus it is not desirable to use it in this experiment. Also, at the end of the first experiment, the vinaigrette with added cheese decolourized from unknown reasons, which can affect the accuracy of the result. Furthermore, since the cheese needs to be molten in order for it to have a stabilizing effect in the vinaigrette, it makes it hard to control the temperature of all samples, which could affect the results. Therefore, it is voted out.
Why a computer with photo-editing software is used?
From the first experiment, it was found out that it was not very practically feasible, as it is very hard to accurately measure average diameter of oil droplets even when very accurate measuring tools (calliper with a scale of as small as 0.02mm). To improve, I have decided to take pictures of the oil layers and calculate the average diameter of oil droplets by the assistance of photo-editing software. I think this can let me get more accurate data.
Hypothesis:
The vinaigrette achieves optimal stability when both egg yolk and honey are added into it.
While cooking
1. Use the measuring cup to obtain 75ml of vinegar and pour it into a glass container. Repeat the process for all 3 containers.
2. Use the measuring spoons to add 25ml of oil into the 4 containers respectively.
3. Use the measuring spoons to add 5mL of honey into one of the containers. Repeat the process to add 5mL of egg yolk into one container, and 2.5mL of honey and 2.5 of egg yolk into the last container.
Adding honey.
Egg white and egg yolk separated.
Adding egg yolk into a container.
4. Close the lids to the containers. Shake them to mix the mixture inside thoroughly. Observe the clarity of the mixture and measure the average diameter of the oil droplets.
Calculation:
Method: Use the photo-editing software to fix an area for sampling. Count the number of oil droplets in the area.
Formulas:
Average area of an oil droplet = Area of sampling area / number of oil droplets
Average diameter of oil droplets = 2 * sqrt(Average area of an oil droplet / p)
t = 0 min
t = 5 min
t = 30 min
t = 1 hour
Since the oil layers of the mixture with added egg yolk and both honey and egg yolk start forming 2 distinguishable layers, the sampling area of the mixtures are changed to 4.63mm * 4.63mm = 21.4369mm2. For Honey, only one measurement is made; for the other 2, the top and bottom layers are sampled separately.
t = 3 hours
t = 6 hours
t = 20 hours
Since the oil layer of the mixture with added honey starts forming 2 distinguishable layers, similar to the other 2 samples, the top and bottom layers are sampled separately.
- Similar to the first experiment, since egg yolk has an emulsifying ability, the samples with egg yolks added are emulsified.
- Similar to the first experiment, since honey has stabilizing ability, the oil droplets of the sample with honey are stabilized and prevented from merging together to some extent.
- After being left alone for an extended period of time (20 hours), the lighter colouration of the top of the vinegar layer of the sample containing only egg yolk indicates that either slow precipitation is occurring or the small oil droplets emulsified are moving towards the top.
- When calculating the average diameters of the oil droplets, assumptions of "all oil droplets are circular" and "there is no oil or other substances between the oil droplets" are made. Also, since the number of oil droplets is counted by hand, the numbers may not be accurate since some droplets may be too small to be visible. Furthermore, since oil droplets are 3-dimensional and they are packed randomly, the numbers and results may not be entirely accurate. To improve, more advanced software could be used to assist in the measurement and calculation of the average size of the oil droplets.
- The vinegar used in this experiment is not as concentrated as the first experiment since it has been diluted a bit with water long before this experiment takes place. Such difference could potentially make the results less obvious since it is unknown whether the concentration of the vinegar will affect the emulsifying and stabilizing effect of stabilizers. To improve, vinegar of higher concentration could be used instead.
Further investigations:
- Since the vinegar used in this experiment has a lower concentration than that in the first experiment, and the resulting stabilizing effect of honey turns out to be different from last time, further investigations could be conducted to find out whether the concentration of vinegar could affect the emulsifying and stabilizing effects of emulsifiers and stabilizers.
- There is still an obvious oil layer on top of the vinaigrette in all 3 samples, which could indicate that not enough stabilizers or emulsifiers are used, thus the oil and vinegar are still not entirely miscible. Therefore, further investigations could be conducted to the minimum amount of emulsifiers needed in order for the vinaigrette to be completely emulsified with no obvious oil layer.
Right before mixing.
After cooking
Observation:
Upon mixing, the oil and vinegar appear to have mixed thoroughly in all 3 mixtures.
Within 30 seconds, the oil and vinegar in all 3 mixtures separated into 2 layers.
After 1 hour, the oil layers of mixtures with added egg yolk and both egg yolk and honey start forming 2 different layers. The bottom layer contains smaller oil droplets while the top layer contains larger ones.
After an extended period of time (20 hours), the top of the vinegar layer of the sample with only egg yolk appears lighter while the other 2 samples do not have such observation.
After 1 hour, the oil layers of mixtures with added egg yolk and both egg yolk and honey start forming 2 different layers. The bottom layer contains smaller oil droplets while the top layer contains larger ones.
After an extended period of time (20 hours), the top of the vinegar layer of the sample with only egg yolk appears lighter while the other 2 samples do not have such observation.
Calculation:
Method: Use the photo-editing software to fix an area for sampling. Count the number of oil droplets in the area.
Formulas:
Average area of an oil droplet = Area of sampling area / number of oil droplets
Average diameter of oil droplets = 2 * sqrt(Average area of an oil droplet / p)
t = 0 min
| Honey | Egg Yolk | Honey + Egg Yolk | |
| No. of oil droplets | 240 | 252 | 255 |
| Avg. area of an oil droplet (mm2) | 0.357281667 | 0.340268254 | 0.336265098 |
| Avg. diameter of oil droplets (mm) | 0.674466564 | 0.658211969 | 0.654328679 |
(From left to right: Honey, Egg Yolk, Honey + Egg Yolk)
t = 5 min
| Honey | Egg Yolk | Honey + Egg Yolk | |
| No. of oil droplets | 37 | 212 | 220 |
| Avg. area of an oil droplet (mm2) | 2.317502703 | 0.404469811 | 0.389761818 |
| Avg. diameter of oil droplets (mm) | 1.717770673 | 0.717625918 | 0.704457351 |
(From left to right: Honey, Egg Yolk, Honey + Egg Yolk)
t = 30 min
| Honey | Egg Yolk | Honey + Egg Yolk | |
| No. of oil droplets | 35 | 203 | 211 |
| Avg. area of an oil droplet (mm2) | 2.449931429 | 0.42240197 | 0.40638673 |
| Avg. diameter of oil droplets (mm) | 1.766168049 | 0.733361366 | 0.719324443 |
(From left to right: Honey, Egg Yolk, Honey + Egg Yolk)
t = 1 hour
Since the oil layers of the mixture with added egg yolk and both honey and egg yolk start forming 2 distinguishable layers, the sampling area of the mixtures are changed to 4.63mm * 4.63mm = 21.4369mm2. For Honey, only one measurement is made; for the other 2, the top and bottom layers are sampled separately.
| Honey | Egg Yolk (top) | Egg Yolk (bottom) | Mix (top) | Mix (bottom) | |
| No. of oil droplets | 8 | 25 | 40 | 27 | 42 |
| Avg. area of an oil droplet (mm2) | 2.6796125 | 0.857476 | 0.5359225 | 0.793959259 | 0.510402381 |
| Avg. diameter of oil droplets (mm) | 1.847102758 | 1.044879109 | 0.826049466 | 1.005435391 | 0.806141734 |
(From left to right: Honey, Egg Yolk, Honey + Egg Yolk)
t = 3 hours
| Honey | Egg Yolk (top) | Egg Yolk (bottom) | Mix (top) | Mix (bottom) | |
| No. of oil droplets | 6 | 16 | 36 | 15 | 41 |
| Avg. area of an oil droplet (mm2) | 3.572816667 | 1.33980625 | 0.595469444 | 1.429126667 | 0.52285122 |
| Avg. diameter of oil droplets (mm) | 2.132850549 | 1.306098886 | 0.870732591 | 1.348933129 | 0.815913506 |
(From left to right: Honey, Egg Yolk, Honey + Egg Yolk)
t = 6 hours
| Honey | Egg Yolk (top) | Egg Yolk (bottom) | Mix (top) | Mix (bottom) | |
| No. of oil droplets | 4 | 9 | 36 | 11 | 40 |
| Avg. area of an oil droplet (mm2) | 5.359225 | 2.381877778 | 0.595469444 | 1.948809091 | 0.5359225 |
| Avg. diameter of oil droplets (mm) | 2.612197772 | 1.741465181 | 0.870732591 | 1.575214525 | 0.826049466 |
(From left to right: Honey, Egg Yolk, Honey + Egg Yolk)
t = 20 hours
Since the oil layer of the mixture with added honey starts forming 2 distinguishable layers, similar to the other 2 samples, the top and bottom layers are sampled separately.
| Honey (top) | Honey (bottom) | Egg Yolk (top) | Egg Yolk (bottom) | Mix (top) | Mix (bottom) | |
| No. of oil droplets | 1 | 2 | 2 | 38 | 2 | 31 |
| Avg. area of an oil droplet (mm2) | 21.4369 | 10.71845 | 10.71845 | 0.564128947 | 10.71845 | 0.691512903 |
| Avg. diameter of oil droplets (mm) | 5.224395544 | 3.694205517 | 3.694205517 | 0.84750887 | 3.694205517 | 0.93832914 |
(From left to right: Honey, Egg Yolk, Honey + Egg Yolk)
Analysis
Result:- Similar to the first experiment, since egg yolk has an emulsifying ability, the samples with egg yolks added are emulsified.
- Similar to the first experiment, since honey has stabilizing ability, the oil droplets of the sample with honey are stabilized and prevented from merging together to some extent.
- After being left alone for an extended period of time (20 hours), the lighter colouration of the top of the vinegar layer of the sample containing only egg yolk indicates that either slow precipitation is occurring or the small oil droplets emulsified are moving towards the top.
Discussion:
- The oil droplets in the oil layer of the sample containing both stabilizers merge together despite the presence of the stabilizers. This could indicate that the stabilizing ability of the honey added may not be strong enough to have significant effects on the vinaigrette.
- The lighter colouration of the top of the vinegar layer only appears on the sample with only egg yolk and doesn't appear in the sample with both stabilizers. This could indicate that the honey added to the vinaigrette can stabilize it to some extent.
- When compared to the samples with only honey or egg yolk added, the sample with both added has the highest stability as it has a consistent colouration and a large number of its oil droplets remain in smaller diameters without merging with each other. However, since there aren't any significant differences between it and the sample with only added egg yolk, it can be concluded that the stabilizing effect of the honey added is not significant, and thus honey cannot efficiently increase the stability of the vinaigrette.
- After being left alone for an extended period of time (20 hours), the oil droplets of all 3 samples merge together to some extent, forming larger droplets if not a connected layer. This could indicate that not enough stabilizers are used, so the vinaigrette can only be more stabilized if more stabilizers are used.
- Even though the amount of both emulsifier and stabilizer is larger (doubled) in this experiment, the stabilizing effect of honey appears to be less significant when compared to the results of the first experiment. This could be due to the vinegar used in this experiment being not as concentrated as the first experiment since it has been diluted a bit with water long before this experiment takes place.
Possible errors and solutions:
- The measuring cup and measuring spoons used are not very accurate, so the measurements of the vinegar, oil and stabilizers may not be very accurate. To improve, more accurate tools, like measuring cylinders, can be used.- The oil droplets in the oil layer of the sample containing both stabilizers merge together despite the presence of the stabilizers. This could indicate that the stabilizing ability of the honey added may not be strong enough to have significant effects on the vinaigrette.
- The lighter colouration of the top of the vinegar layer only appears on the sample with only egg yolk and doesn't appear in the sample with both stabilizers. This could indicate that the honey added to the vinaigrette can stabilize it to some extent.
- When compared to the samples with only honey or egg yolk added, the sample with both added has the highest stability as it has a consistent colouration and a large number of its oil droplets remain in smaller diameters without merging with each other. However, since there aren't any significant differences between it and the sample with only added egg yolk, it can be concluded that the stabilizing effect of the honey added is not significant, and thus honey cannot efficiently increase the stability of the vinaigrette.
- After being left alone for an extended period of time (20 hours), the oil droplets of all 3 samples merge together to some extent, forming larger droplets if not a connected layer. This could indicate that not enough stabilizers are used, so the vinaigrette can only be more stabilized if more stabilizers are used.
- Even though the amount of both emulsifier and stabilizer is larger (doubled) in this experiment, the stabilizing effect of honey appears to be less significant when compared to the results of the first experiment. This could be due to the vinegar used in this experiment being not as concentrated as the first experiment since it has been diluted a bit with water long before this experiment takes place.
Possible errors and solutions:
- When calculating the average diameters of the oil droplets, assumptions of "all oil droplets are circular" and "there is no oil or other substances between the oil droplets" are made. Also, since the number of oil droplets is counted by hand, the numbers may not be accurate since some droplets may be too small to be visible. Furthermore, since oil droplets are 3-dimensional and they are packed randomly, the numbers and results may not be entirely accurate. To improve, more advanced software could be used to assist in the measurement and calculation of the average size of the oil droplets.
- The vinegar used in this experiment is not as concentrated as the first experiment since it has been diluted a bit with water long before this experiment takes place. Such difference could potentially make the results less obvious since it is unknown whether the concentration of the vinegar will affect the emulsifying and stabilizing effect of stabilizers. To improve, vinegar of higher concentration could be used instead.
Further investigations:
- Since the vinegar used in this experiment has a lower concentration than that in the first experiment, and the resulting stabilizing effect of honey turns out to be different from last time, further investigations could be conducted to find out whether the concentration of vinegar could affect the emulsifying and stabilizing effects of emulsifiers and stabilizers.
- There is still an obvious oil layer on top of the vinaigrette in all 3 samples, which could indicate that not enough stabilizers or emulsifiers are used, thus the oil and vinegar are still not entirely miscible. Therefore, further investigations could be conducted to the minimum amount of emulsifiers needed in order for the vinaigrette to be completely emulsified with no obvious oil layer.
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