Functional Role Of Gelatin In Food Industry: Salad Dressing, Gel, And Cake

What is Gelatin made of?

Gelatin is a nutrient-rich protein obtained from collagen found in animals’ bones and skin. Gelatin contains important amino acids. It is used to make foods, cosmetics, and many more. Gelatin is used in the food industry for its emulsifying, gelling, stabilizing and other unique features to enhance the food taste or texture. The neutral taste profile of gelatin allows it to be blended with a broad range of flavours. The following section will discuss the functional role of gelatin as an ingredient for various food items.

Partially hydrolyzed collagen extracted from animal bones, the skin produces gelatin, a collection of proteins and peptides. Gelatin is an essential amphiphilic macromolecule that surfaces active features that can behave as an emulsifying agent in oil-in-water emulsions. Emulsifiers form layers between medium and suspended particles, and in this way, the emulsion is stabilized. Salad dressings contain a lot of water and oil, and they usually have a low pH. In low-fat versions, the water levels are higher. Gelatin containing substances are termed gelatinous substances. A biopolymer called gelatin is made from collagen's thermal denaturalization. Collagen’s properties influence gelatin’s qualities. Collagen is a fibrous protein derivative that plays a pivotal role in synthesizing gelatin molecules. Collagen is found in animal bones and skin. A plethora of proline, glycine and 4-hydroxy proline residues are present in gelatin. Collagen is a polypeptide chain that contains around 50 to 1000 chains of amino acids. Gelatin is a powder that is translucent, tasteless and colourless. Gelatin is employed in making stable emulsions as it is a great oil-in-water emulsifier. In foods, an emulsifier is a chemical compound that assists in one liquid's suspension in another, as in salad dressing. Salad dressings are semi-liquid or liquid that is employed for flavouring salads. Some of the links within and between component proteins are broken during hydrolysis. Gelatin is reversible, which denotes that it can be briefly heated and melted after setting. The procedure is repeated numerous times.

Salad dressings that are oil-based sauce require a stabilizing agent and an emulsifier, especially when the aqueous phase is high and the fat concentration is low. Gelatin aids in preventing the breaking down of emulsions. The interface's surface tension can be controlled to prevent the two phases from separating. Widening the aqueous phase and raising the dispersed phase are the two ways to stabilize an emulsion. Gelatin is a good water-binding compound. In water, it can absorb up to several times its weight. It is best suited for low-calorie emulsions having a creamy consistency, a smooth texture and an excellent gloss. Gelatin contains hydrophobic regions on the peptide chains and acts as an emulsifying agent. Hydrocolloids are employed in various food to enhance shelf life and quality. Gelling and thickening agents are the two major applications. Gelatin dissolves in glycerol, hot water and acetic acid, but organic solvents such as alcohol cannot dissolve gelatin. Gelatin has a higher viscosity under stress. When the mixture is kept cool and gelatin concentration is high, the water-gelatin mixture’s viscosity is maximum. Gel formation, texture, and viscosity are closely linked qualities determined primarily by gelatin’s molecular size, structure and temperature. Gelatin produces sols or colloidal solutions by combining polymer chains of varying lengths. The sols get transformed into gel on cooling and revert to sols on warming. It is why gelatin-based products melt in the mouth, ensuring a continuous discharge of flavour. A significant attribute of gelatin is that the gelling process can be reversed endlessly. Gelatin is a hydrocolloid which is a polysaccharide or protein that generates textural properties like gelling and thickening when combined with water. Gelatin has several functional qualities because of its distinctive structure and amino acid content.

Functional Role of Gelatin in Salad Dressing

Desserts prepared with flavoured and sweetened gelatin or processed collagen products are called gelatin desserts or jello. Gelatin is amphoteric and shows both basic and acidic features, including base and acid amino groups. It enables it to react with various substances like food additives and sugar. Gelatin’s versatility is because of such interactions. It assists in preserving small ice crystals, acts as food emulsifiers, and stabilize foam present in foods. Several fruits contain proteolytic enzymes, but they are included in various gelatin desserts. The gelatin molecule is split into protein fragments or small peptides to create a solid gel. Gelatin has various functional features. It is used as a gelling agent as gelatin gels dissolve at low temperatures and are set gently. It is why gelatin is used as an ingredient for gelling purposes. Enzymatic degradation is often used for breaking down bonds and converting collagen to gelatin. By breaking certain peptide bonds and cross-linkages, gelatin is derived. It is a peptides mixture obtained from collagen. A hydrophilic colloid is a gelatin in water. A colloidal mixture is one in which a substance's particles are spread through a constant medium. Although the particles are larger than those present in a solution, they are quite small. The particles cannot be seen, and they cannot also be filtered. The particles do not settle to the container's bottom. Gelatin is hydrophilic, which means it attracts water.

The mixture is stirred for a few minutes until the gelatin has completely dissolved. When collagen is heated, the bonds that connect the collagen are broken. The helical shape begins to unravel, leaving free-floating protein chains behind. When cold water is added to the jello mixture and then refrigerated, the chains rearrange into a compact triple helix shape. The mass operates like a sponge while cooling, absorbing the supplied water. There are breaks in the helix in some locations while a twisted network of polypeptide chains in others. Water is trapped between the chains' pockets after creating a kind of net. The protein net is adequately strong for holding the jello in the shape it is molded into.

Gelatin is the main ingredient of jello which is a gelatin-based dessert. Animal collagen, which forms connective tissues like ligaments, tendons, bones, etc., is used to make gelatin. Collagen extraction is done by boiling, drying and treating the bones and hides of animals like pigs and cows with strong bases or acid. For making gelatin, the collagen is dried. It is then crushed into a powdered form and finally sifted. The gelatin protein's shape is a triple helix shape at room temperature. A double helix is created when two nucleotides' chains intertwine in a spiral shape that looks like a ladder. Polypeptide chains, which are distinct amino acid chains, are aligned and twisted around one another in the gelatin protein. Proline, glycine and hydroxyproline are the common amino acids. The helix is held together by weak bonds. Therefore, adding boiling water to gelatin powder creates a gelatin mold.

Functional Role of Gelatin in Gel

The final product’s consistency is referred to as texture. Gelatins help individuals create the desired texture by hardening or softening a product. Gelatin contains around 99% protein when it is dry; however, tryptophan is not present in gelatin, and it does not contain threonine, isoleucine and methionine. Therefore, it is a nutritionally incomplete protein. Like collagen, the same amino acid profile is present in hydrolyzed collagen. The most abundant amino acids present in hydrolyzed collagen are glycine, hydroxyproline and proline. It accounts for about half of the overall amino acid content. The reason behind the chain’s tight packing is glycine. The conformation is restricted due to the presence of proline. For gelatin’s gelation features, it is crucial. In mousses, ice cream, and several desserts, gelatin is employed to achieve a firm and frothy consistency. A melting-in-mouth, delectable experience is ensured. Creams, cheesecakes, fillings and so on contain gelatin. Gelatin is extensively used in confectionery as it is a thickener that helps in converting a liquid into a solid. In pastry also, gelatin is employed as a thickening agent. Gelatin is used for thickening jellies and creams between cakes’ layers. Beautiful glazes are made using gelatin. Bakers use gelatin for setting liquid. Due to the versatility of gelatin, it is used both in savoury and dessert dishes. Gelatin is used for setting jelly, soups, and so on.

A thickening agent is a compound that increases a liquid's viscosity without impacting its other characteristics. Thickening agents enhance emulsions' or other ingredients' suspension, increasing the product's stability. Thickening is generally a solvent-polymer interaction. It includes non-specific entanglement of conformationally irregular polymer chains. Thickening takes place above overlap concentration which is a critical concentration. The polymer dispersions show Newtonian behaviour below such concentration but non-Newtonian behaviour above it. Conformationally disorganized random coils’ physical entanglement leads to polysaccharide dispersions’ viscosity. Each hydrocolloid molecule can move independently, and thickening does not happen in dilute dispersion. The molecules in a concentrated system come nearby, restricting molecules' movement. The thickening process is free-moving molecules’ transformation into an entangled system. Hydrocolloid thickening agents might be thought of as network producers’ entanglement. Two gelatin forms are used in the pastry kitchen: sheet and powdered gelatin. It gives whipped fillings a lovely creamy texture while also enhancing their stability. Pastry chefs prefer sheet gelatin. Bloom rating is used for measuring gelatin’s strength.

Gelatin has unique surface characteristics like film-forming capability and cohesion, and the stabilization and function of colloidal protectors. It is associated with gel formation, water binding capability and thickening. Gelatin is widely used in commercial dessert shops and bakeries. The shelf life of gelatin is good, and therefore whipped cream can hold its shape longest. Fresh whipped cream is used to top cupcakes or cakes, but the frosting is fragile and delicate. Water can seep out of the icing over time, causing it to disintegrate or weep. A stabilizer assists in the sturdiness and firming of the whipped cream. Whipped cream stabilized can be frosted or piped onto cakes without losing its melt or shape. The physicochemical characteristics of gelatin provide a stable system that increases the product’s shelf life.

The gelatin helps the whipped cream maintain its shape even in high temperatures. Whipped cream is a classic example of air-in-water foam. Gelatin lowers the water’s surface tension, enabling foaming. During the gelling procedure, gelatin binds the water within the foam and creates a thin layer around the fat globules. As a result, the foam gets stabilized. The air cells are trapped by a covering of fat droplets supported by a protein layer. When the cream is whipped, some of the proteins get partially denaturized. Whipped cream is an aerated emulsion stabilized at the water-air interface by a framework of partially fragmented fat globules. Non-fat milk powder or gelatin is utilized for whipping cream.

When heavy cream is being beaten, the beaters, the container and the heavy cream must be super cold. A stabilized whipped cream is ideal for people who prefer lighter, less sweet frosting. Stabilized whipped cream has the same taste and flavour as ordinary whipped cream. It lasts longer and is thicker, and this property makes it perfect for piping onto desserts. Fresh whipped cream is not normally stable to be utilized as a deep filling or piped without adding gelatin, a stabilizer. Whipped cream is stabilized with powdered sugar. It is utilized as a cake topping. Stabilized gelatin containing whipped cream is good for making it robust for piping, specifically as a rich filling. Once stabilized, the delectable topping can be piped to frost a cake or used as cake topping for cupcakes. The whipped cream becomes stiff, and transporting becomes very easy.

Therefore, from the above discussion, it can be concluded that gelatin is a versatile substance. It helps in the formulation and encourages innovation. It is also an important protein source. Gelatin contains the essential amino acids and is obtained from collagen. Its unique capability of reacting to heat is one of the biggest advantages. The gelatin-based products melt at a particular temperature and set again once they cool. The gelatin's gelling, stabilizing, emulsifying, thickening, and binding features are accompanied by several other features that make it useful in a broad array of applications. Thus, the pleasing characteristics of gelatin make it an essential part of the food industry.