Gelatin (gelatine) is a tough, colorless, and flavorless protein derived from collagen off various animal sources, usually pig or cattle. It’s made up of amino acids that are strung together like a molecular chain. When processed, it creates a translucent and flavorless food that has unique properties when heated or cooled. It is one of the most versatile ingredients in any chef’s arsenal. Gelatin is a thermoreversible protein gel that is utilized in both hot and cold food preparations.
Its role in products like gummy bears gives them their gelatinous texture and notable chewiness. Gelatin is also a key ingredient in many other confectionery such as fondant, meringue, and marshmallow. It gives cakes and marshmallows structure and viscosity, keeps ice cream from crystallizing, and speeds up the breakdown of pills in the stomach.
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In addition to its use in food, gelatin is frequently used in medicinal products including vitamin and medication capsules. Moreover, gelatin is a component of cosmetics like shampoos, skin creams and lotions, and hair gels.
HOW IS GELATIN MADE?
Gelatin is created by a process of hydrolysis and extraction. Animal skins and bones are boiled in water to extract the collagen. Collagen consists of three polypeptide chains organized in a triple helix, and can be hydrolyzed under either acidic or alkaline circumstances. Gelatin created by acid hydrolysis is typically referred to as type A whereas gelatine produced by alkaline hydrolysis is referred to as type B.
After collagen extraction, the solution is then cooled, forcing the collagen to form into a gel. This gel is washed until all the impurities have been removed, and the final product is dried and pulverized into small granules or powder.
Usually, unprocessed raw materials such as pig skins and bones are sourced from a nearby slaughterhouse to quickly process them.
Upon arrival, skins are processed directly in the production of gelatine, whereas bones are washed to remove meat and fat residues, yielding dry, degreased bone. The bones are subsequently treated with hydrochloric acid, which dissolves the phosphates. They are then precipitated with lime to yield di-calcium phosphate, which is then used in cattle feed. The remaining bones are made up of bone or ossein collagen. The collagen, whether bone or hide, is then hydrolyzed as needed using acid or alkali (typically lime).
The resulting solution after hydrolysis includes around 6–7% gelatin. Extractions are repeated until the source material is depleted; the finest quality gelatin is found in the first extractions. After filtering, the extractions are vacuum evaporated to 30 to 40% gelatin. The solution is then sterilized at 284°F (140°C) before being crash-cooled to form a jelly.
The concentrated gelatine jelly is then extruded and air dried before being crushed and blended to the appropriate specifications. The average finished product contains 84% protein, 14% moisture, and 2% ash.
WORKING WITH GELATIN
Gelatin is generally employed as a gelling agent, chilling to make clear elastic thermoreversible gels. In the European Union, gelatin is denoted by the E number E441 as a gelling agent. Its ability to form a gel is used in a variety of dishes and desserts. The so-called bloom number determines the quality and gelling strength of gelation. The greater the number, the stronger the gelation; for example, a 250 bloom strength implies high gelation power. Bloom strengths range from 60 to 260, but higher strengths are also available.
The molecules’ amphiphilic nature endows them with excellent emulsification (for example, in whipped cream) and foam-stabilizing capabilities (as in mallow foam). Proteins have the ability to stabilize foams. When a gelatin-containing mixture is whipped, the foam can be solidified by allowing the mixture to cool. Dehydration causes irreversible conformational changes that can be utilized to produce surface films. In addition to these, gelatin also acts as a granulation binder for pressed sugar tablets.
Gelatin is also employed in the clarification of wine and fruit juices. It achieves this by binding to the molecules in the beverage and precipitates to the bottom of the bottle with them. This makes it easier to eliminate the microscopic particles.
Gelatin is a product whose microbiological quality is important. If it is subjected to bacterial proteolysis, its functional properties are affected.
Gelatin is hygroscopic—it absorbs moisture from the air. So it must be stored in a way that prevents it from absorbing water. Mold growth can begin if the moisture level rises up to around l6%. Furthermore, caution needs to be taken when working with gelatin solutions since they form an excellent medium for bacterial development. Being an animal product, there is always a risk of contamination from pathogens.
HEALTH BENEFITS AND ALTERNATIVES
Gelatin is abundant in protein. It also includes important amino acids for bone health. Its protein levels is ideal for individuals who are looking to increase their protein intake without the additional calories. It can also help with digestion and the absorption of important vitamins and minerals in the body. Collagen, the major component of gelatin, is also widely recognized for its medicinal advantages since it aids in skin elasticity, bone and joint strength, and muscle growth. These are the reasons why many take it as a supplement.
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It is worth noting thought that gelatin and the foods it is used in should not be consumed by vegans and vegetarians because it is an animal product.
Some religious groups, particularly Jews and Muslims, steer clear from consuming gelatin-containing products. Gelatin is regarded as one of the most contentious food components in Halal and Kosher food industries. Fortunately, there are alternatives. An example of this is Kosher gelatin. Kosher gelatin is processed from Kosher animals, in accordance with the Jewish food Law. In the United States, the FIT company is the largest supplier of Kosher gelatin. One should easily determine if a product is made from kosher by reading the label. Kosher and certain halal gelatin are made from cattle.
Other alternatives to animal-derived gelatin are plant-based, such as agar (seaweed), pectin, and guar gum.
References:
W. P. Edwards (2000). The Science of Sugar Confectionery. The Royal Society of Chemistry.
M. Gibson (2018). Food Science And The Culinary Arts. Academic Press.
J. Valisek (2014). The Chemistry of Food. John Wiley & Sons, Ltd
