With gelatine, unique and tailored textures can be created. Just think of those clear gummy candies made from gelatine: the gum-like elastic texture, its characteristic bite and that typical melting behavior can only be achieved with gelatine. Foamed textures can also be formed with Gelatine: marshmallows and chewy candies just wouldn’t be possible without it. Even in fat-reduced products and spreadable sausages, gelatine can create a smooth, creamy texture and a rich mouthfeel. In dairy products, gelatine enables a variety of consistencies to be created – from creamy to firm – and, at the same time, prevents syneresis. In cakes and pastries, powdered gelatine and leaf gelatine are used to texturize fillings. It creates a wonderfully creamy mouthfeel and also improves the stability and sliceability of whipped fillings.
Gel formation and viscosity
Gel formation, viscosity and texture are closely related properties, determined mainly by the structure, molecular size and temperature of the gelatin. Being a mixture of polymer chains of different lengths, gelatine forms colloidal solutions or sols. On cooling, these sols convert to gels; on warming, they revert to sols. This unlimited reversibility of the gelling process is an extremely important technological property of gelatine.
As the melting point of gelatine-based confectioneries is close to that of body temperature, a very smooth mouthfeel, a pleasant melting behavior and optimal flavor release are guaranteed. For harder gummy candies, higher Bloom Value gelatines are advisable, whereas lower Bloom Value gelatines create a softer texture. The gel formation ability of gelatine is the precondition for many functionalities and applications: gummy candies and gelled desserts, for example, would not be possible without gelatin, providing the quality, transparency and brilliance.
Stabilizing: Always in good shape
Creams and toppings can be stabilized with gelatine – a property that is also important in combination with other functionalities, such as foam forming or emulsifying. When it comes to cheese spreads or to creamy desserts, fillings or toppings, the required firmness can be adjusted with gelatine. With a higher level of firmness, they maintain their smooth and sharp contours and stay easy to slice, which is important when you think of beautiful pastries or cake fillings.
Water binding capacities
As you may have read before, gelatine has excellent water binding properties. Not only important for fat reduction, if gelatine is added to meat, the drip loss induced by baking, frying and grilling can be reduced. This is an economic factor for the industry that also enhances the end product quality, which is important for the consumer. Especially in low-fat meat products, water binding is extremely important. The addition of small amounts of gelatine hydrolysate improves both the softness and spreadability of meat products made from chopped meat and fat tissue. Gelatine can also bind water during thawing and cooking. In canned products such as corned beef, gelatine is added to absorb the meat juice, which is released during sterilization. It also holds the pieces together and improves slicing.
A well-known problem in yogurts and other dairy products is syneresis. This chemical or physical effect occurs during the storage of two-phase systems and can lead to compromised quality: the unsightly release of water caused by phase separation. In yogurt, it’s the whey separating from the yogurt curds. By lowering the interfacial tension and, at the same time, binding and thus immobilizing the water, gelatine emulsifies and stabilizes the compounds, prevents syneresis and ensures an appealing end product during the entire storage period.
With its excellent foam building properties, gelatine can also be used to incorporate air into multi-phase emulsions through whipping or gas injection – from marshmallows and mousse desserts to cheese preparations. Gelatine decreases the surface tension of the water, facilitating foaming. Within the foam, the gelatine binds the water during the gelling process and surrounds the fat globules with a thin film. As such, it also stabilizes the foam. Large amounts of air are retained in the product, and different bubble sizes mean that a range of textures can be produced, from creamy to fluffy. Thanks to gelatine’s gelling and stabilizing properties, product texture is maintained, even during lengthy periods of storage.
In the case of marshmallows or aerated chews, gelatine prevents the recrystallization of sucrose. The ability to form and stabilize foams comes from the surface properties of gelatine: they are based on the fact that the gelatine side chains have charged groups and that certain parts of the collagen sequence contain either hydrophilic or hydrophobic amino acids. Both tend to migrate towards surfaces reducing the surface tension of aqueous solutions.
Stable oil-in-water emulsions
As gelatine is also an excellent oil-in-water emulsifier, it can be used to create stable emulsions. Oil-containing sauces such as vinaigrette, mayonnaise and salad dressings need an emulsifier and a stabilizing agent, particularly when they have a low fat content and a high aqueous phase. Gelatine helps to prevent emulsions breaking down. To avoid separation of the two phases, the surface tension of the interface can be adjusted. Stabilizing an emulsion can be done in two ways: by increasing the dispersed phase or by thickening the aqueous phase. Because of its ability to absorb up to 10 times its own weight in water, gelatine is a very effective water-binding agent – perfect for low calorie emulsions with a smooth consistency, creamy texture and a nice gloss.
In ice-cream production, the same function is utilized: Gelatine stabilizes heterogeneous suspensions and dispersions, and enhances the formation of very fine crystals, thus preventing coarse crystallization. Here, multifunctional compounds of different gelatine types with tailored properties can be used. This enhances product storage stability and melting properties – perfect for low-calorie frozen desserts and fat-free ice creams. Also in confectionery products, gelatine controls the recrystallization of sucrose. In photographic applications, gelatine acts as a carrier for light-sensitive coatings
The adhesive characteristics of gelatine are probably its most well known property: it’s been used as a glue for 8000 years. Today, it still is used in many technical applications, but also in the food industry. For example, cereal bars with low water content are made with gelatine hydrolysate as binding (adhesion and cohesion) agent. Gelatine solutions are capable of fully covering the surface contours of the particles to be affixed to each other and, as a result, adhesion forces are built up. Once the gelatine solution has been evenly distributed over the surfaces to be joined, it starts to gel on cooling.
Ideal colloidal solutions
Technologically speaking, gelatine is a hydrocolloid; it forms colloidal solutions with water. They’re actually regarded as ideal colloidal solutions. Other hydrocolloids are, for example, pectin, carrageenan, gum arabic, xanthan, guar gum and locust bean gum, to name just the most important ones. In the food industry, they are used for their functional properties; but, compared with gelatine, their functionalities are rather limited. In many formulations, Gelatine can replace one or more hydrocolloids with only little adjustements.
Gelatine also enables the development of delicious half-fat, low-fat and “light” products, as it has enormous water binding capacities. Thus, calorie-free water can be incorporated to replace high-calorie fat. With the according technical knowledge, you get the same volume and comparable mouthfeel, and fewer calories. In products such as half-fat butter, reduced fat cheese and fat-free ice cream, gelatine helps to minimize the fat content without compromising on taste. In pizza cheese for example, gelatine not only reduces the fat content but also improves the melting properties. When replacing fat with water, giving structure and texture to the water is important. Gelatine scores points by being able to create a fat-like matrix in emulsions that exhibits shear-thinning properties and a fat-like creaminess. Thus, the addition of gelatine results in a smooth, creamy texture and mouthfeel – with fewer calories and a compatible appearance and taste.
In meat products GELITA’s functional proteins can be used to create sliceable aspics, sausages and spreadable products, all of which have significantly fewer calories than other meat or sausage products. Spreadable sausages in particular, with their high fat content, are perfect candidates for fat reduction. Here, gelatine provides excellent texture and improved spreadability – while reducing the fat and calorie content. GELITA offers special multifunctional gelatine compounds made from different collagen types. They have excellent water-binding properties while acting as an emulsifier and a stabilizer at the same time.