First experiment: How much sugar is needed to balance the tartness of vinaigrette?

-First Experiment-

Mok Wing Yiu, Yoyo (3035474729)

How much sugar is needed to balance the tartness of vinaigrette?

(Source: https://gph.is/2oVW7yy)

Introduction:

Vinaigrette is one of the best salad dressing you could have in this world. This simple combination of oil and vinegar surely gives you a new insightful taste. Traditional vinaigrette usually use olive oil as the fat base, but we do something creative here. Instead of using olive oil, we use bacon fat to have an extra meatier taste in our vinaigrette. Since one of the ingredient: vinegar, is very sour and acidic, we have to add some sugar to balance the tartness in the vinaigrette. However, different website suggested that using different kind of sugar in the same amount will give the exact sweetness. It is really the case? The aim of this project is to find out how many amount of each types of sugar is needed to add to the vinaigrette in order to balance the tartness.

Trial Experimental Test:

What ingredients and equipments need?

Total ingredients for separating into 6 samples:

1. 12 strips thick cut bacon diced into 1/8-inch cubes
2. 9 cloves garlic peeled and minced
3. 3 tablespoons maple syrup (for set A)
4. 3 tablespoon honey (for set B)
5. 9 tablespoons Dijon mustard smooth or grainy
6. 3/4 cup apple cider vinegar
7. 3 teaspoon coarse ground black pepper
8. 3 teaspoon kosher salt

Equipment needed:

1. A saucepan
2. 6 sample bowls
3. Tablespoons (1/2 tablespoon, 1 tablespoon)
4. A teaspoon
5. A knife
6. A cutting board
7. A measuring cup

Who do the shopping?

Myself.

Where to obtain ingredients/equipment/tools, where cook?

All the ingredients are bought at supermarket (PARKnSHOP).

And it's cooked in my own kitchen.

When start cooking? 

Cooked directly after ingredients buying.

Why is this investigation important? 

Different website suggested that using different kind of sugar in the same amount will give the exact sweetness. The aim of this project is to find out how many amount of each types of sugar is needed to add to the vinaigrette in order to balance the tartness.

Hypothesis of the project:
Ha: Different types of sugar have different needed amount to balance the tartness.
H0: Different types of sugar have the same needed amount to balance the tartness.

Independent variable: Amount of sugar added
Dependent variable: Sweetness-to-tartness

How to test it?
The cooked bacon vinaigrette will be separated into 6 sample bowls. For experiment Set A, different amount of maple syrup  (0.5 tablespoon; 1 tablespoon; 1.5 tablespoon) will be mixed in. For experiment Set B, different amount of honey (0.5 tablespoon; 1 tablespoon; 1.5 tablespoon) will be mixed in. Then, a taste test with 10 taste testers will be conduct. Drinking water to rinse of the previous taste between sample test is compulsory in this test.

How to quantify the dependent variable?
10 taste taster will rate the sourness and sweetness (from the scale of 1-7) of the sample.

The smaller the difference between sweetness and sourness, the more balance the taste it is, which means the tartness is balanced.

The Cooking Part:

1. Place the bacon in a medium saucepan over low heat and stir until some of the fat begins to render from the bacon. Raise the heat to medium and cook the bacon, stirring frequently, until it is crispy.

2. Use a slotted spoon to transfer the crisp bacon to a paper towel lined plate, keeping all of the fat drippings in the pan.

3. Return the pan to the burner. Add the garlic, swirl, and immediately add the remaining dressing ingredients. Bring the mixture to a boil and let it cook for 1 minute, or until the dressing coats the back of a spoon. It should leave a trail when your finger is drawn through the dressing on the back of the spoon.

4. Stir in the bacon.

5. Separate the semi-finish vinaigrette evenly into 6 sample bowls. Add in 0.5 tablespoon, 1 tablespoon, 1.5 tablespoon amount of sugar (Set A: maple syrup; Set B: honey) in to separate bowls. Mark down the amount of sugar added to each simple.

6.Mix a teaspoon of sample-to-test with a small bowl of salad each time. Conduct taste tests.

Data analysis and results:

After collecting taste tester rating, we can come some conclusion.

Firstly, by analysing Sample A and B separately.

For sample A (maple syrup), according to graph 1, we have found that the sweetness and tartness of the mean difference between sweetness and tartness is negatively correlated. 

The tartness of vinaigrette is balanced if 1.5 tablespoon of maple syrup is added as it has the smallest difference between sweetness and tartness. 

(Graph 1)

For sample B (honey), according to graph 2, we have found that the sweetness and tartness of the mean difference between sweetness and tartness is also negatively correlated. 

However, unlike Sample A (maple syrup), the tartness of vinaigrette is already balanced if 1 tablespoon of honey is added as it has the smallest difference between sweetness and tartness. More than 1 tablespoon of honey is being added, the vinaigrette becomes too sweet with over-covered the tartness of the dressing.

(Graph 2)

So, by comparing the amount of sugars needed to be added in Sample A (1.5 tablespoon of maple syrup) and Sample B (1 tablespoon of maple syrup) to balance the tartness of the vinaigrette, we can conclude that the amount of different types of sugar need to be added to balance the tartness is not the same. 

The null hypothesis (H0) is rejected. 

Different types of sugar have different needed amount to balance the tartness.

The recipes online are not correct, they should not suggest people to add the same amount if they are using different types of sugar. 

When we make our own vinaigrette, we should pay attention to what kind of sugars we are using in order not to over- or under- balance the tartness of the vinaigrette as it would affect the taste of the dressing.

Discussion:

Possible errors:

Since this experiment is done at home and without accurate scientific measurement. Even though I have been really cautious, there might still be some error made. For example, the measurement of volume of sugar might not be really accurate, because the viscosity of honey and maple syrup is high, the remained volume on the tablespoon might reduced the amount of sugars that needs to be get in the sample bowl. 

In addition, errors could be made in the taste test too. Given that "sweetness" and "sourness" are in deed quite subjective to people, and it varies among people. Even if I have already taken mean as the comparing value, it might not truly reflect how well the tartness is being balanced as mean could be easily affected by extreme value. 

Science behind such result:

The difference between the amount of different types of sugar needed to be added to vinaigrette to balance the tartness might due to the composition of the two sugars: maple syrup and honey.

Maple syrup is composed by mainly sucrose and with some glucose and fructose (Stuckel, 1996). Sucrose is a disaccharide, which is commonly used as table sugar in our daily life (Fung, 2009) and it is a combination of glucose + fructose. 

Picture 1 (Sucrose)

While on the other hand, honey is composed by mainly fructose and with some glucose and fructose (Doner, 1977). Fructose is a monosaccharide, even though it has the same chemical formula to glucose, it has a special chemical structure (see picture 2). It is said to be the sweetest sugar due to its special structure stimulate the taste bud the sweet sensation. 

Picture 2 (Fructose)

Fructose is nearly as twice (1.73) sweeter than sucrose in its crystallised form (Rayner, 2010), but when it's dissolved in water, its sweetness depends on temperature. It is because they will inter-convert between 4 structure as shown in Picture 3.

(Picture 3)

β-D-fructopyranose is responsible for the sweetness of the fructose. It is present for 68% at 25°C, its concentration decreases rapidly with the increasing of temperature, and only about 50% of fructose is present as β-D-fructopyranose at 80 °C (Henry, Crapo & Thorburn, 1991). So in another words, it is less sweet in higher temperature.

As the amount of fructose in honey is higher than that in maple syrup, and we conduct this taste test under room temperature, this might be the reason why less honey added taste the same as more maple syrup added. So, the amount of honey and maple syrup needed to be added to balance the tartness is not the same.

Reference:

1. Doner, L. W. (1977). The sugars of honey—a review. Journal of the Science of Food and Agriculture, 28(5), 443-456.
2. FUNG, J. (2009, February). Nutrient and Health - Carbohydrates: Sugars. Retrieved March 22, 2020, from https://www.cfs.gov.hk/english/multimedia/multimedia_pub/multimedia_pub_fsf_31_02.html
3. Henry, R. R., Crapo, P. A., & Thorburn, A. W. (1991). Current issues in fructose metabolism. Annual review of nutrition, 11(1), 21-39.
4. Rayner, L. (2010). The natural canning resource book: a guide to home canning with locally-grown, sustainably-produced and fair trade foods. Flagstaff, AZ: Lifeweaver LLC.
5. Stuckel, J. G., & Low, N. H. (1996). The chemical composition of 80 pure maple syrup samples produced in North America. Food Research International, 29(3-4), 373-379.