CLASS 10

GELLING & THICKENING AGENTS

Kelcogel F (low-acyl gellan gum): It is a hydrocolloid of the microorganism Sphingomonas elodea. It is a water-soluble polysaccharide produced by fermentation. This gelling agent can be used alone or in combination with other products to produce a wide variety of interesting textures. Extremely effective in low levels of use in the formation of gels. Benefits: Excellent stability, high gel resistance, heat stable, sparkling clarity, excellent flavor release, can be easily combined with other hydrocolloids, compatible with proteins.

Preparation tips: Form gels at really low concentrations: 0.05%

Gellan: Gellan is relatively unique in molecular gastronomy because it is a highly engineered ingredient that has only been applied to the food industry since the early nineties.

GELLAN: is created by the bacteria Pseudomonas elodea or Sphingomonas elodea. It was first discovered in the laboratories of Merck and Co., under the division of Kelco, in 1978. It was approved for food use in 1992 by the United States' FDA. Today, C.P. Kelco continues to market the product under a variety of brands. Technically, Gellan is a microbial exopolysaccharide, although all this really means is that it is secreted by a microbe (a bacterium) and is a polysaccharide, or a long chain of molecules based on carbohydrates, similar to flour or starch. Gellan gum is gaining traction in the food industry as a replacement for other hydrocolloids and in biological research as a replacement for agar.

Gellan function

As a general rule, you can think about using Gellan as a substitute for agar. The difference between the two is that Gellan can withstand higher temperatures and produces the same viscosity at half the concentration of Agar. Both Gellan of high acyl and Gellan of low content of acyl can be used to gel, thicken and stabilize, like other hydrocolloids. Its special qualities are related to the particular temperatures it can withstand and the sensation in the mouth that it imparts.

Applications Gellan Gellan is most often used in molecular gastronomy to create unique textures that can be served hot and to create a variety of fluid gel textures.

CARRAGEENAN: Carrageenans are linear sulphated polysaccharides extracted from certain species of red algae (seaweed) of the Rodophyceae class. The concentration and composition of carrageenan found in marine algae varies according to the species of plant. For example, some seaweeds may be weighed in kappa and carrageenan iota, while others may contain only a small amount of carrageenan lambda. To extract carrageenan from raw seaweed, the algae is harvested, dried and processed.

There are many types of carrageenan beyond kappa, iota and lambda, but we only use these three types in the kitchen. You can also see these ingredients mentioned with their corresponding lowercase Greek letters: κ-carrageenan (kappa), ι-carrageenan (iota), λ-carrageenan (lambda).

Carrageenan function

One of the most important properties that truly differentiates carrageenan from other hydrocolloids is its ability to develop complexes or interact with proteins and is widely used to thicken, gel or stabilize solutions based on dairy products. Carrageenan is not a surfactant, but it will stabilize existing emulsions. The three-dimensional network that helps to stabilize the emulsions also works to suspend the particles.

Iota Carrageenan is a large thickener and gelling agent used mainly with fruits and dairy products to form a soft reversible and flexible heat gel. Iota Carrageenan requires calcium ions to develop a gel and, like all carrageenans, is vegetarian and a great alternative to gelatin. Iota Carrageenan forms a soft gel, especially in the presence of calcium.

Kappa carrageenan gels since it reacts with calcium or potassium salts. In the presence of calcium, Kappa carrageenan forms rigid and brittle gels. But in the presence of potassium salts, Kappa carrageenan forms very firm and elastic gels.

Lambda Carrageenan will not form a gel, but can be used as a thickener.

Native readers in the United States may notice that many heavy cream and yogurt products available in supermarkets use carrageenan as a thickener. All carrageenans show stabilizing properties in the presence of milk proteins.

Xanthan Gum: A secretion of polysaccharides from bacteria produced by the fermentation of sugars such as glucose, sucrose or lactose. The additive is used mainly as a food thickening agent or stabilizer. It is a large molecule highly soluble in water and provides a thick solution in small quantities.

Xanthan hydrates quickly at all temperatures, so it has a strong tendency to cluster. A popular dispersion method is to disperse in oil (either in a 1: 1 or 1: 2 ratio of xanthan in oil) followed by a vigorous shake and, optionally, an effort to remove the remaining lumps. Another method is to thoroughly mix the xanthan with a small amount of sugar, preferably in a mortar, before dispersing. This delays hydration enough to allow the gum to disperse before it has a chance to form lumps. As when working with other hydrocolloids, vigorous whipping or mixing with a blender work very well to aid 

CARRAGEENAN IOTA:

A natural hydrocolloid derived from a specific type of red algae found in the North Atlantic. This sulfated polysaccharide contains two sulfur by disaccharide and serves to offer soft and elastic gels. These properties are the result of the ability of the molecule to flex in helical structures. It should not be confused with Kappa carrageenan or carrageenan lambda.

CARRAGEENAN KAPPA:

A natural hydrocolloid derived from a specific type of red algae found in the North Atlantic. This sulfated polysaccharide contains a sulfur by disaccharide and, due to this characteristic, creates a strong and brittle gel. These properties are the result of the ability of the molecule to flex in helical structures. It should not be confused with carrageenan iota. It should not be confused with carrageenan lambda.

Culinary uses

Increase in the viscosity of the liquid. Keeping the emulsions homogenized and the particles suspended for long periods. Stabilization of oil-soluble flavors in water-based drinks. Valued for its ability to withstand a range of temperature and pH. Due to its thermal stability, it is used in canned and pasteurized products. Due to its shear dilution character, xanthan is used in salad dressings; which means that at high shear its viscosity decreases

and low shear maintains its viscosity. In gluten-free cooking, xanthan reinforces gluten-free flour blends by adding "stickiness". Excessive xanthan will create an undesirable "snotty" texture. This can be overcome by using it in combination with guar gum obtained from guar beans.