THE BIG QUESTION

 

Will leaving a yogurt sphere in sodium

alginate for a longer period of time

 create a thicker layer of gel around it?

 

HYPOTHESIS

 

The gel layer that forms around a yogurt sphere will increase

 in size the longer the yogurt sphere is left  in a sodium alginate solution.

Our research included reading about and defining the following words associate with Molecular Gastronomy, as well as discovering many facts about the chemical and physical changes as it applies to food science.

 

MOLECULAR GASTRONOMY

Molecular Gastronomy is a branch of food science.  It involves investigating the physical and chemical changes of different foods when they are cooked.  It makes the taste, color and texture of food look different, interesting and modern. 

 

REVERSE SPHERIFICATION

Reverse Sphereification is one example of Molecular Gastronomy. It is the process of adding a liquid with calcium in it, such as milk or yogurt, to a mixture of sodium alginate. This chemical reaction between the calcium and the sodium alginate creates a gel like layer around the liquid.

 

CALCIUM

Calcium is the mineral that we have the most of in our body. We think about it most when we talk about bones and teeth. It gives our bones and teeth strength and hardness.

 

DISTILLED WATER

Distilled water is a kind of purified water where impurities are removed by boiling water into a steam and then condensing it back into a liquid.

In our experiment it is important that there is no calcium left in the  water we use that will interfere with the chemical reaction between the yogurt and the sodium alginate solution.

 

SODIUM ALGINATE POWDER

Sodium Alginate is refined brown seaweed. The seaweed is dried, followed by cleaning, boiling, gelling and pulverizing it. It has many uses. We are using it as a gelling material to see the chemical reaction between it and yogurt with a high percentage of calcium.

 

                                                   CHEMICAL CHANGE

A reaction that changes an item from what it was to something new and it can’t go back to it’s

original form. It has been changed chemically. The chemical reaction in spherification is between the calcium and sodium alginate.  The calcium takes the place of the sodium

 alginate creating a gel like layer to forma round the yogurt containing a high amount of calcium.

 

CHEMICAL REACTION

The chemical reaction in in spherification is between the calcium and the sodium alginate causing the thin gel like layer to form around the yogurt containing a high amount of calcium.

 

RAVIOLI

The term used to describe the sphere that forms after the yogurt is left in a bath of sodium alginate solution.

 

SPHERIFICATION

Adding sodium alginate to a liquid putting it into a calcium

chloride bath.  The liquid will form gel inside the sphere creating

 a gel ravioli with no liquid.

 

 

 

FUN FACTS

 

Herve This is a French scientist who is considered to be the father of Molecular Gastronomy.

Nicholas Kurti was a Hungarian physicist.  Together in 1988 they came up with the name Molecular Gastronomy to apply food science to describe cooking techniques.

 

Chefs around the world use molecular gastronomy to create dishes that are not only delicious, but amazing to look at.

 

Food Foams are a part of molecular gastronomy.

One of the most popular foams is foamed espresso for al the coffee lovers out there!

 

Herve This was a French scientist and who is considered to be the father of molecular Gastronomy.   He was the first chef to experiment with it in 1988.

 

You can turn almost any liquid or pureed food into small sphères. The sphères have a gel layer on the outside and  a liquid center and are called popping boba.

 

 

 

 

 

 

 

 

Manipulated Variable (Independent):

The time we left the yogurt in the sodium alginate solution. 

 

Reponding (Dependent):

The amount of gel that forms around the yogurt sphere (ravioli).

 

Controlled Variables:

Brand of yogurt used in experiment (Oikos Extra Creamy Blueberry Greek Yogurt)

The amount of water used to disolve the sodium alginate

The amount of sodium alginate used 

 

Procedure

 

Measure and pour 3 cups of distilled water into a glass bowl.

 

Measure 3/4 teaspoon of sodium alginate powder

 

Mix sodium alginate slowly into distilled water with a whisk

 

Let sodium alginate solution sit overnight to allow any bubbles caused during whisking to disappear

 

Spray 1 tablespoon with oil and wipe off extra with paper towel

 

Measure one tablespoon of yogurt levelling it off with a knife

 

Wipe any excess yogurt off the measuring spoon with a paper towel

 

Weigh the measuring spoon with the yogurt on the digital scale

 

Drop the yogurt into the sodium alginate solution

 

Let the yogurt ball sit in the sodium alginate solution for the desired amount of time stirring gently with a spoon

 

Remove the yogurt sphere from sodium alginate solution with a slotted spoon and place in a bowl of tap water

 

Place the yogurt sphere on a plate with parchement paper to let excess water to be removed

 

Using a slotted spoon move the yogurt ravioli to the digital scale

 

Record the weight

 

Transfer the yogurt sphere to a plate with the rest of the yogurt 'raviolis'.

 

Taste the yogurt raviolis at the end of each trial to determine the one with the best 'pop'.

 

 

 

 

 

 

                                                 

 

 

 

   RESULTS

 

Trial #1

 

Weight before       Time      Weight after

                                                                                                                       8 grams             0 mins       8 grams

8 grams             2 mins       8 grams

8 grams             4 mins       9 grams

8 grams             6 mins       9 grams

8 grams             8 mins     10 grams

8 grams           10 mins     10 grams

 

Trial #2

 

Weight before    Time          Weight after

7.8 grams           0 mins           7.8 grams

7.8 grams           2 mins            8.3 grams

7.8 grams           4 mins            8.9 grams

7.8 grams           6 mins            9.5 grams

7.8 grams           8 mins           10.0 grams

7.8 grams          10 mins          10.4 grams

 

 

Trial #3

 

Weight before         Time        Weight after

                                                                                                                    7.9 grams              0 mins       7.9 grams

                                                                                                                    7.9 grans               2 mins       8.2 grams

                                                                                                                    7.9 grams              4 mins       9.1 grams

                                                                                                                    7.9 grams              6 mins        9.7 grams

                                                                                                                    7.9 grams              8 mins       10.2 grams

                                                                                                                   7,9 grams             10 mins       10.5 grams

  In each of the three trials, the longer the yogurt sphere was left in the sodium alginate solution, the heavier it was.

 

In the first trial... the weights during 0 and 2 minutes were both 8 grams.   Weights during 4 and 6 minutes were both 9 grams and weights during 8 and 10 minutes were both 10 grams.

The grams scale we were using showed that the longer the yogurt sphere was left in the distilled water, the heavier it got. The scale was not exact enough though to tell an enough of a difference between minutes 0 and 2, 4 and 6 or 8 and 10 minute times.

 

In the second trial... The starting weights were all 7.8 grams.  Weights continued to go up every two minutes that we left the yogurt sphere in the sodium alginate solution.  

After 2 minutes, the weight went up by 0.5 grams to weight 8.3 grams

After 2 more minutes at the 4 minute time it went up by another 0.6 grams to weigh 8.9 grams

After 2 more minutes at the 6 minute time, it went up by another 0.6 grams to weigh 9.5 grams

After 2 more minutes at the 8 minute time, it went up by another 0.5 grams to weigh 10.0 grams

During the last two minutes at the end of the 10 minute time, it went  up another 0.4 grams to weigh 10.4 grams

 

In the third trial... The starting weights were all 7.9 grams. Weights continuted to go up evey two minutes thatwe left the yogurt sphere in the sodium alginate solution.

After 2 minutes at the 2 minute time the weight went up by 0.3 grams to 8.2 grams

After 2 more minutes at the 4 minute time the weight went up by 0.9 grams to 9.1 grams

After 2 more minutes at the 6 minute time the weight went up by 0.6 grams to 9.7 grams

After 2 more minutes at 8 minutes, the weight went up by 0.5 grams to 10.2 grams

After 2 more minutes at the end of the 10 minute time, the weight went up by another 0.3 grams to weigh 10.5 grams

 

The weights went up pretty evenly every two minutes. The weight that went up the most was in the third trial. From 2 minutes to 4 minutes, the weight went up by almost a gram. This was definately an outlier in our experiment.  We think that we might just not have been as careful in trying to get most of the extra water off of the yogurt sphere during the transfer of it to the weigh scale

 

 

CONCLUSION

 

The yogurt sphere (also called a ravioli) increases in weight the longer it is left in the sodium

alginate solution. We conclude that the gel layer increases around the yogurt ravioli the longer it stays in the solution.  

 

 

Things To Try Next Time

Things that we would try next time to see if it improved the experiment are:

 

1. Increasing the calcium level of the yogurt by adding calcium chloride to it.

 

2. Putting the sodium alginate in the fridge so the gel will form better.

 

3. Using a blender to mix the sodium alginate into the water.

 

4. Increasing the amount of sodium alginate dissolved in the water.

Applications and Spinoffs

 

1.  We also want to try spherification. This is the opposite of Reverse Spherificaton

where you add sodium alginate to a liquid and put it into a mixture of calcium chloride.

 We want to see if juice will form a gel inside the sphere to create a gel ravioli

 with no liquid inside as is used in bubble tea.

 

2.  A second application we want to try is adding calcium chloride to juices and then freezing them in mini ice cubes.

We would then put the cubes in a sodium alginate solution to create juice “raviolis”.

 

 

Outliers/Sources of Error

 

1. In our first trial we used a scale with measurement to the grams.

As you can tell from our graph, it did not give measurements that were accurate enough to show a difference between different amounts of time the yogurt was left in the sodium algainte bath.

For our second and third trials we were able to use a scale that measured to the tenths of a gram.

 

2. In each of our trials, it was never possible to get all of the excess water off of the ravioli and that could contribute to some weights not being exact.

 

Research

 

1. Elaina’s Experiments: Molecular Gastronomy

You Tube KGETNEWS

 

2. Mylastbite.com Adventures in Molecular Cooking Dec 22, 2008

 

3. Sciencebuddies.org

Making yogurt spheres using Molecular Gastronomy

 

4.  The Science of Spherification

                                                                                                                        capecrystalbrands.com

We would like to thank our moms for helping us do this project and putting in effort with us. We also want to thank them for buying all the stuff we needed for the project. They helped us print out what we needed. We want to thank Mme MacIntyre for letting us go out during class time to work on our project.