There is no doubt that food has to taste good; it is of paramount importance. At the same time, it should look attractive, smell fresh, and, once in the mouth, deliver a whole gamut of textural and sensorial delights. Mouthfeel is critical and formulators have long known the value of gelling agents, stabilisers, foam formers and surfactants. But what if there was a single ingredient that could do this all, and more, and even make regular foods healthier? Oliver Wolf, head of B2B marketing, global marketing and communication, Gelita, elaborates more.
With a profile of technological properties, gelatine acts as a gelling and binding agent in food applications, as well as a builder and stabiliser of foams and emulsions. It is also a natural product, and free from e-numbers. Despite its popularity, however, ingredient manufacturers such as Gelita have noticed that the industry’s understanding of the fundamental properties of gelatine has begun to be overlooked during the last few years, and that its true potential remains unexploited.
The name of this multifunctional hydrocolloid came from the Latin word “gelatus”, meaning frozen, rigid or solidified. In water, gelatine swells rapidly, dissolves on warming to a low viscosity solution, and forms a clear gel when it cools. The reversibility of this gelling process is by far the most important technological property of gelatine. It also has the ability to melt at body temperature, an attribute that gives confectionery a very smooth mouthfeel and a pleasant feeling of melting combined with optimal flavour release.
Even though gelatine is usually associated with the characteristic texture, form and bite of gummy bears, this highly purified collagen protein can be applied to many other applications. Providing a variety of versatile technological properties, it is often found in confectionery, dairy, meat and bakery. As a texturizing agent, gelatine acts as a gelling, binding and whipping agent, stabiliser and emulsifier, and as a perfect film and foam former. It can also help to reduce fat while keeping a pleasant texture, and improve the nutritional properties of various foodstuffs. In fact, the versatility of gelatine, as well as its nutritional properties, make it the ideal multifunctional ingredient for foodstuffs with taste, texture and mouthfeel. As it is free from preservatives, fat, carbohydrates, purine and cholesterol, gelatine allows manufacturers to create modern products that combine nutritional value and indulgence to be positioned in the growing market for clean label or health and wellness products.
Some application examples are:
Because of its amphiphilic properties, gelatine acts as a surfactant, and decreases the surface tension of water. Therefore, it is a whipping and emulsifying agent. Within the water phase of the foam or emulsion, the gelatine forms a gel and thus stabilises the system. By manipulating the size and amount of the air bubbles or oil droplets within the system, it is possible to create many different textures – from creamy to fluffy. And, by using gelatine’s ability to gel, the viscosity of the continuous water phase is increased to a level that prevents the separation of the dispersed phase – a basic requirement for the production of stable forms or emulsions.
Another benefit of gelatine’s foam-building property is that mousses and instant desserts gain increased volume, delivering a bigger serving size to the consumer with fewer calories. And these benefits are not just applicable to the desserts market. In the savoury sector too, they can help to cut fat and calories, as well as contributing to stability and mouthfeel.
From a thermodynamic point of view, foams are unstable two-phase systems that tend to collapse with time. Therefore, to create a successful foamed product, it is crucial to maintain a stable foam. Whenever a soft-foamed product with a narrow air bubble size distribution and low mean bubble size is needed, gelatine’s foaming and foam stabilisation properties come into play. These properties are fully exploited by the confectionery industry in products such as marshmallows, wafer fillings, and fruit chews. Here, gelatine fulfils three functions at once – foam formation by reducing the surface tension of the water phase, providing long-term stability by stabilising the foam’s continuous liquid phase, and texturizing by providing the desired elasticity.
A phase changer
In systems with a high-water content, gelatine immobilises the water phase and thus increases the viscosity by foaming gel, subsequently making the production of many low-fat products possible. Without the use of gelatine, products would not obtain the desired texture or even remain liquid. In dairy products, for instance, gelatine prevents the product matrix from shrinking, which would cause unsightly and undesired syneresis. Therefore, the gelling properties of gelatine are often associated with increased water retention and product stability.
In systems with a low-water content, the gelling power is responsible for the stable yet elastic texture of the products throughout their shelf life.
Healthy and indulgent
With significantly fewer calories than fat, gelatine is able to create a fat-matrix in emulsions that exhibit shear-thinning properties and creaminess similar to fat. Its gelling assets play a critical role in the development of, for instance, low-fat butters, margarines and spreads. To maintain their consistency, structure and spreadability, the water is combined with gelatine to create a texture that mimics the full fat equivalents. By making use of gelatine’s gelling, emulsifying and stabilising properties, various low-fat dressings as well as low-fat dips and sauces can also be produced that comply with the highest quality standards.
In the meat processing industry, gelatine is used to manufacture aspic products and terrines, which have a considerably lower calorie content than other meat products such as sausages and cold cuts. Furthermore, collagenous proteins also make it possible to cut down on calories in parboiled specialties such as hot dogs, frankfurters or Lyon sausages without compromising on flavour or texture.
Clean and clear label applications
Furthermore, gelatine offers additional benefits in foamed multiphase systems such as nougats that contain emulsified fat in a supersaturated sugar solution. In these products, gelatine not only acts as a foaming, stabilising and texturizing agent, it also functions as an emulsifier and enhances the mouthfeel by impacting the recrystallisation of sucrose. This multifunctional approach can also be found in foamed milk-based desserts such as mousses, yoghurts, curds and ice creams, which are three-phase systems of air; oil and water. Here, gelatine decreases the surface tension of the water, enhancing foam generation by mechanical whipping. With gelatine, it is easy to clean up and shorten the ingredient list as a variety of different functionality requirements can be fulfilled with a single ingredient. In today’ world of clean and clear labelling, brevity is paramount, providing a huge benefit for consumers looking to make healthy and well-informed choices. Classed as a foodstuff in its own right, and not as an additive, gelatine can be used to replace ingredients with e-numbers for clean label formulations – a feature that gelatine as a hydrocolloid possesses. Even thought it is a protein, gelatine has low allergenic.
GELATINE’S KEY PROPERTIES
Gelatine offers properties not easily imitated by other hydrocolloids.
- Melt-in-the-mouth feelings that leads to intensive flavour and aroma release. Scientists have not yet been able to find a gelling protein or polysaccharide that universally replicates this property.
- Thermally reversibility: Some plant hydrocolloids, such as carrageenan and agar, form thermally reversible gels, but melting points are significantly better.
- Surface activity: Although gelatine does not perform as well as gum Arabic in regards to emulsifying and stabilising properties, it still is an important characteristic.
- Customisation ability: Gelatine is available in different gel strengths and particle sizes.
- Easy to use: Gelatine gels within the pH range typical of foods and does not require salts, sugars or food acid additions to set.