In addition to a small amount of water and inorganic salts, the rest of gelatin is protein, which accounts for more than 82%. Gelatin contains 18 amino acids and is more nutritious than vegetable gums. It has excellent physicochemical properties that vegetable gums do not have: it is chewy and melts in the mouth. Gelatin is a versatile edible gum and few other food additives have so many functions at a same time. It is an important and widely used food additive.
Thickener and gelling agent
If there is a little gelatin in the solution, it will not form a gel, but its loosely entangled molecules will slow down the movement of water to increase solution viscosity. For example, a small amount of edible gelatin is added to stirred yogurt to thicken these products. If there is a lot of gelatin in solution, it can form a thermally reversible hydrogel when it cools. The three-dimensional network binds water and other materials together and gives food a stable shape. Gelatin candy is more elastic and chewy than agar and pectin candy. It makes cake surface smoother and flatter, and improves its stability and sliceability.
Emulsifier
Gelatin has hydrophobic and hydrophilic groups. Its hydrophobic groups are attached to oil, while the hydrophilic groups are in contact with water, forming a film on the oil droplet surface. When gelatin is added to oil-water mixture, the oil is broken down into small droplets that are evenly dispersed in water. This property is used to make canned meat, milk candy and ice cream. It effectively prevents solution from becoming a mixture where water and oil are layered, and gives food the creamy texture.
Foaming agent
It is similar to emulsifiers, when used as a foaming agent. The hydrophobic and hydrophilic groups of gelatin can greatly reduce the surface tension of water. When the solution is whipped, gelatin molecules encase air to form bubbles easily. In marshmallow or cream, gelatin will expand their volumes to make taste fluffier.
Stabilizer
Gelatin molecules with electric charges form a protective film on oil droplets or bubbles surface. The electrostatic repulsion precludes droplets and bubbles from fusing together during collision, making them evenly distributed. The gelatin in cream not only creates foam, but also keeps the cream in a stable state for a long time and keeps it from collapsing. It also slows down the growth of sugar crystals and ice crystals, making them smaller in size and giving food a smooth texture.
Fining agent
The positively charged gelatin can attract negatively charged tannins in fruit juices to form flocculent colloid. This colloid absorbs protein, metal ion and other suspended matters from the juice. When the charge of colloid is neutralized, it shrinks and sinks to the bottom. These precipitates are filtered to obtain a clarified juice. The bitterness is reduced and its taste becomes milder due to the removed tannins.
Dietary supplement or nutraceuticals
Hydrolyzed gelatin is rich in protein and virtually free of carbohydrates and fat, making it an ideal low-fat, low-calorie food. It is often added to low-fat foods or dietary supplements. It is directly absorbed by the body and complements the proteins in meat to enhance its nutritional value. Long-term use of collagen peptides can rejuvenate skin, strengthen bones and cartilage, and promote hair growth.