CLASS 11

SPHERIFICATIONS

Sodium Alginate: A particular form of alginic acid that is usually found within the cell wall of brown algae of the Laminaria species. This specific form contains sodium ions, and in food, it is an unflavored gum used as a thickener, emulsifier or in spherifications with calcium substrate. For spherification it is recommended to use calcium lactate and calcium gluconate, since calcium chloride leaves a bitter taste.

Name sodium alginate (E401)

Polysaccharide origin extracted from brown algae.

Thermo-reversible gel texture in the presence of calcium ions; Slimming thickener in the absence of calcium

Clear clarity, transparent

Dispersion: cold water; the dispersion can be improved by mixing with sugar (3-5x); Add. of acidic liquids can cause the precipitation of alginic acid

Hydration (dissolution) cold or hot water; If it's cold, let it hydrate for a couple of hours

pH 2.8-10

Independent temperature adjustment

Not melting (but prolonged heating at low / high pH will destabilize the gel)

Developer requires calcium to gel

Inhibitor precipitates as alginic acid at pH <4 (corrected by the addition of sodium citrate); gels in too high concentrations of ions / salts

Tolerates up to ~ 50% ethanol (D. and hydrate in water before the addition of alcohol)

Viscosity of the solution: low in neutral water, high at lower pH (<5.5)

Typical concentration: 0.5-1% for normal spherification; [0.3-5%] *

Sinergies Syneresis yes

Storage

Because sodium alginate reacts with calcium, alginate baths should not be discarded through the sink, as this could create plumbing problems and delays. For similar reasons, it is important to use distilled water, since impurities could also create spherification problems.

Sodium Alginate is a natural polysaccharide product extracted from the cell wall of brown seaweed that grows in cold water regions. The natural function of alginate is to give flexibility to the seaweed, it is common to find higher contents of alginate in species found in troubled waters. Sodium alginate was first studied in 1881 by English chemist ECC Stanford

Sodium alginate is used to gel in the presence of calcium, as a shear dilution thickener in the absence of calcium, to stabilize emulsions or foams and to form films. In the Modernist, sodium alginate is used mainly with calcium salts to produce small spheres similar to caviar and large with liquid inside that explodes in the mouth. There are two main processes to create spheres, basic spherification and reverse spherification.

The most common application of sodium alginate in molecular gastronomy is to create spheres using the spherification technique developed by Chef Ferran Adria at el Bulli restaurant in 2003. The resulting spheres have a thin membrane of gel and are filled with liquid.

In the food industry, sodium alginate is used as a thickener in sauces, syrups and ice cream toppings. By thickening the pie fillings with sodium alginate, the softening of the dough is reduced by the filling liquid. Water-in-oil emulsions such as mayonnaise and salad dressings thickened with sodium alginate are less likely to separate into your original oil and water.

A common use of sodium alginate in the food industry is to make the strips of paprika inside the pitted olives. The strips are made with pepper puree that is gelled into thin sheets using sodium alginate and then cut into strips.

Sodium alginate is also used as stabilizers in ice cream. The addition of sodium alginate reduces the formation of ice crystals during freezing, giving a smooth result.

Another use of sodium alginate is to form sodium alginate or calcium films and calcium alginate fibers.

Temperature (gels and melts): not affected by temperature. Gel is heat stable up to 150 ° C (302 ° F) but prolonged heat treatment at low or high PH may destabilize the gel

PH tolerance: well, it does not gel at pH below 3.7, therefore, increase PH when using acidic ingredients such as lemon juice. Sodium citrate is generally used to increase PH, but it can increase salinity if it is not used moderately. Heartburn is a problem with

the basic spherification, but not with the reverse spherification. In reverse spherification, a gel membrane forms around the edible liquid, but the edible liquid itself does not gel.

Other tolerances: up to 50% ethanol, but sodium alginate must be hydrated before adding alcohol

Inhibitors: PH <3.7 For preparations below this PH, adjust it by adding sodium citrate, but keep in mind that sodium citrate tastes salty and will alter the final taste, so it should be used sparingly.

How to use sodium alginate

Concentration range: 0.5-1% for spherification. Up to 1.5% for other applications.

Hydration: cold or hot water

Dispersion: under shear using the blender, do not use hard water or liquids with calcium or acid content for dispersion. The dispersion can be improved by mixing it with sugar or another powdered ingredient before adding it to the liquid. Air bubbles are usually trapped in the solution. To eliminate the bubbles, let it sit in the refrigerator for a few hours or you can place it in a vacuum chamber.

Configuration: high speed, cold adjustment.

Special features: N / A

Chemical reaction

There are two methods to prepare an alginate gel. The one originally used by Chef Ferran Adria is the diffusion method in which the calcium ion that is crosslinked is diffused from an external reservoir to an alginate solution (Basic Spherification). Gels are formed when a calcium salt is added to a solution of sodium alginate in water. The gel is formed by chemical reaction, calcium displaces the sodium of the alginate, holds together the long molecules of alginate and the result is a gel. No heat is required and the gels do not melt when heated. This is in contrast to agar gels where the water must be heated to about 80 ° C to dissolve the agar and the gel forms when it cools below about 40 ° C. The third property of alginates is the ability to form films of sodium or calcium alginate and calcium alginate fibers.

Basic Spherification

The Basic Spherification technique is ideal for obtaining spheres with a very, very thin membrane that is almost imperceptible in the mouth. It results in a sphere that explodes easily in your mouth as if there were no solid substance between your palate and the liquid. The main problem with this technique is that once the sphere of the calcium bath is removed, the gelling process continues even after rinsing the sphere with water. This means that the spheres must be served immediately or they would become a compact gel ball without magic liquid inside. The other problem with this technique is that gelation does not occur if the liquid acidity is high (PH <3.6) but this can be corrected by adding sodium citrate to the liquid to reduce the level of acidity before the spherification process. The Basic Spherification technique does not work with ingredients that have a high calcium content. Examples of Basic Spherification are "Spherical Mango Ravioli", "Liquid Pea Ravioli", "Cointreau Caviar" (shown below). Learn more about Basic Spherification.

Reverse spherification

The reverse spherification technique is much more versatile than basic spherification, as it can form spheres with almost any product. It is best for liquids with high calcium content or alcohol content. Contrary to spheres made with the Basic Spherification process, these spheres have a thicker membrane and are durable, since the gelation process can be stopped when the sphere is removed from the sodium alginate bath and rinsed with water. Thanks to these characteristics, the spherical reverse spheres can be manipulated more easily and can be used in more ways (for example, as fillers in sponge cakes or mousses, in cocktails or they can even be marinated in flavored olive oil for a few days) . Examples of inverse spherification are "Yogurt spheres", "Liquid mozzarella spheres" and "Spherical olives" (shown below). Learn more about Reverse Spherification.

The science of spherification

Sodium alginate is a natural polysaccharide product extracted from brown algae that grows in cold water regions. In the presence of calcium, sodium alginate forms a gel without the need for heat.

In the Basic Spherification, the gelation takes place thanks to the diffusion method in which the calcium ion that is crosslinked is diffused from an external deposit to an alginate solution. Gels are formed when a calcium salt is added to a solution of sodium alginate in water. The gel is formed by chemical reaction, calcium displaces the sodium of the alginate, holds together the long molecules of alginate and the result is a gel. It is not required heat and the gels do not melt when heated. The gel coating is formed inside the drop. Because the calcium ions continue to diffuse towards the center of the drop even after removing the sphere from the calcium bath, the gelation process continues and will eventually form a solid gel sphere.

In reverse spherification, calcium ions diffuse from the drop into the alginate bath, forming a gel layer outside the drop of flavored liquid. Because the calcium ions are diffusing from the inside out and no alginate molecules enter the drop, the gelation process stops as soon as the spheres are removed from the alginate bath. This allows you to store the spheres for later use.