Yogurt Ravioli

A liquid spheres, encased with a gel membrane, are a unique and amazing way to serve food.

A perfect sphere of yogurt should have a thin layer of edible membrane.

What is spherification?

A culinary technique known as spherification lies at the heart of many of Chef’s avant-garde dishes. Spherification is the process of encasing liquid food in a thin polysaccharide membrane that pops open when swallowed, releasing a blast of flavor—whether it's yogurts, juice, olive oil, or another gastronomic delight.

William Peschardt, a food scientist at Unilever, was the first to patent the notion of using spherification-like procedures for food production in the United Kingdom in 1942. The technology, which involves utilising ions to initiate a gelling process, has since found a number of applications in the food business.

How Does Spherification Work?

Spherification makes use of a unique characteristic of some gelling substances. These substances only gel when particular molecules, such as calcium or potassium, are present. A sphere is formed when the reactants are allowed to contact each other for a particular amount of time.

The two main ingredients in this approach are calcium chloride and sodium alginate. Sodium alginate is derived from seaweed, while calcium chloride is a salt used in the production of cheese. By dissolving sodium alginate directly into the fluid, it is utilized to gel the chosen liquid. The liquid will get sticky as a result, and proper dissolution will require mixing. After that, the liquid is left to set to eliminate any bubbles.

A bath is made using calcium chloride and water once everything is ready. Depending on the desired spherical size, the liquid is then placed into the bath with a spoon or syringe. The spheres are removed once they have been set and washed with water to remove any excess calcium chloride. When the gel comes into touch with the calcium chloride, it forms a membrane that encases the liquid.

The longer the calcium lactate is in contact with alginate solution, the more rigid the gel will become, as more crosslinks are formed. The calcium ions are able to cross link the alginate polymers because they can form two bonds.

In this blog, we will study the relationship between the thickness of gel membrane and the time the yogurt is put in alginate solution.

Experimental Question?

How long the yogurt should be put in the alginate solution to form a thin layer of gel around it? What is the time taken to form a thin, unbreakable gel around the yogurt to form yogurt ravioli that is neither too thin nor too thick? These liquid spheres, encased with a gel membrane, are a unique and amazing way to serve food. A perfect sphere of yogurt should have a thin layer of edible membrane. However all ingredients have a different rate of diffusion. In order to make the perfect ravioli, I will examine how long should the calcium rich yogurt be put in the alginate solution, to have a thin edible membrane with a liquid interior.

Recipe

Video

https://video.wixstatic.com/video/6a890d_b4da479c1cb949e699dc1973f49ab196/1080p/mp4/file.mp4

Results:

Time in alginate bath and Membrane Thickness
 1 Minute = 0.45 mm
 2 Minute = 0.64 mm
 3 Minute = 0.78 mm
 4 Minute = 0.90mm
 5 Minute = 1 mm
 10 Minute = 1.5 mm
 20 Minutes = 2 mm

The thickness of gel membrane kept in the alginate solution for 5, 10 and 20 minutes was measured and recorded. The thickness of gel was difficult to measure in other timings. So using the formula D=L2/4t, diffusion constant was calculate as 8.3x10^-6. Using the value of D, the diffusion distance (L) was calculated for 1, 2, 3 and 4 minutes.

From the table we can see that the thickness of gel membrane increase with time in linearly with a slope of 1 mm every 5 minutes. Thus we can see that diffusion is affected by time.

The data above suggests that with increase in time the yogurt is put into alginate solution, the thickness of gel layer also increases. Thus with increase in time, more calcium ions are able to cross link the alginate polymers thus creating a gel.

Conclusions and Future Directions This report has discussed the relationship between time and thickness of gel membrane by scooping calcium rich yogurt into alginate solution. An increase in the thickness of gel membrane was found corresponding to the time yogurt was put in solution. There is an increase of 1mm thickness after 5 minutes. The results thus suggest that diffusion is affected by time. It would be interesting to find out the effects if the concentration of calcium is increased in yogurt and also the concentration of sodium alginate is increased in the solution. How fast would the gelation take place? What will its impact be on the flavor of the yogurt?