Gelatin (or gelatine) is a protein made from the partial hydrolysis of collagen, which is generally derived from the skins and bones of porcine (pork), bovine (beef or cattle), and fish.
You may have cooked the bone broth at home, and noticed the surface of the broth looks like a clear jelly texture after the boiled bone soup cools down. This phenomenon is caused by gelatin, which is produced during the cooking process.
Gelatin is often used as a gelling agent, stabilizer, emulsifier, thickener, and clarifier in food and capsules. Let’s see more details.
- Differences with industrial grade
- Compare with Collagen and Hydrolyzed gelatin
The top four commercial sources are mainly porcine skin/bone and bovine hide/bone. Marine sourced gelatin (e.g. fish) is only produced and applied on a small scale.
However, with religious or ethical reasons from pig and beef gelatin, as well as diseases such as BSE (Bovine spongiform encephalopathy) and foot-and-mouth disease, fish gelatin can be a replacement.
It is made from pig skins or bones. Pigskin based one is the most commercially used gelatin in the world owing to its cheaper price. However, its applications are restricted in Islamic countries as it is not halal.
It is made from bovine hides or bones, which can be accepted as kosher and halal, complies with the law of Muslims and Jews, but not vegan friendly.
The parts of farmed & fresh fish (e.g. skin, bones, scales, and fins) can be used to produce fish gelatin. These fish species include cold-water fish such as alaska cod, pacific cod, green pollock, and salmon; and warm water fish such as tilapia, grass carp, squid, and tuna.
Versus porcine and bovine gelatin
With the similar functionalities of gelling, foaming, emulsifying and binding, fish gelatin can be used as a substitute for bovine and porcine gelatin with the following two advantages:
- Acceptable for all religions and cultures and is almost suitable for all consumers.
- Without the risks of disease that would happen in bovine and porcine.
Compared with pig and bovine gelatin, fish gelatin has lower molecular weight, lower gel strength and lower melting temperature, resulting in lower market demand.
But this is a unique property in some specific applications. For example, fish gelatin confectionery melts faster at a higher temperature and releases its flavor more quickly in your mouth, which gives you a flavorful feeling. So fish gelatin is suitable to be used in desserts which needs a low melting point and quick flavor release in the mouth.
Meanwhile, fish gelatin has a more or less fishy smell, and this smell limits its application.
Generally speaking, compared with mammal sources, gelatin derived from aquatic animals has poor gel properties is mainly due to its much lower imino acid content (proline and hydroxyproline), especially from cold-water fish. The higher the content of imino acids in gelatin, the better the gel properties.
Chicken gelatin has a high gel strength, commonly made from chicken skin or bones, which is rich in collagen.
Gelatin is made from the skin, bone, cartilage, and other connective tissue rich in collagen from animals (pig, beef, fish, chicken, etc.). The edible gelatin is high in protein, low in heavy metal and other impurities.
It is strict in selecting raw materials for producing edible gelatin. Fresh, strictly quarantined animal bones or skins that have not undergone any chemical treatment are required. Also, animal raw materials from epidemic areas and with infectious diseases cannot be used.
It cannot be produced from noncollagen parts of animals, such as horns, horse hoofs.
By the way, dicalcium phosphate is a major by-product in the production process of gelatin. It is mainly used as calcium and phosphorus supplements in feed and can be easily digested and absorbed by livestock and poultry.
The manufacturing of gelatin is generally with two principal processes:
Commonly treat skins/bones with acid, alkaline, or maybe enzyme to release collagen from raw materials.
The acid treatment is more suitable for collagen with a lower degree of cross-linking (e.g. fish collagen and pig skin collagen). This method with the advantage of short process time, maybe 24 hours is enough (1). Gelatin obtained in this process has a lower viscosity.
The alkaline treatment can be applied for collagen with a higher degree of cross-linking. Alkalines can also saponify fat, dissolve and remove soluble impurity proteins. Although high-quality gelatin can be produced in this way, with the disadvantage of a long production time, usually takes 8-12 weeks (2). Gelatin obtained in this process has a higher viscosity.
2. Thermal extraction
This process is using hot water to make collagen partially hydrolyzed to gelatin.
It is necessary to control the degree of gelatin degradation to limit the production of gelatin hydrolysate, which are small molecules that have no gel characteristics that will defect the quality of gelatin.
Gelatin is made of protein, water, and inorganic salts. Protein is the primary component, its content reaches around 80-90%. The remaining components are mainly moisture (8%-13%) and a small amount of inorganic salts (less than 1%).
There are generally more than 20 kinds of amino acids linked by peptide bonds that make up the protein in gelatin, of which the main amino acids are glycine, proline and hydroxyproline.
The following is the general composition:
- Glycine: 1/3.
- Imino acids (proline and hydroxyproline): 1/3
- Proline: 10%.
- Other amino acids: 1/3.
- Does not contain or contains a very small amount of cysteine and tryptophan.
There are various ways to classify the types of gelatin, for example, form the sources, manufacturing processes, appearance, purity, and uses.
From the different animal sources, there are bovine, porcine (maybe further divided into organic grass-fed type or not), poultry, and marine gelatin. The first two are the most common to see in the market.
It can be divided into acid method (type A), alkaline method (type B) and enzymatic types if from the manufacturing process. Commonly, gelatin derived from pig skin is referred to as type A, beef hide sources can be either referred to as type A or B.
Powder, granular and sheets
Available in the forms of powder, granular, and sheets (leaves).
The powdered and granulated forms are suitable to use directly in food, mixed with other additives, or use separately.
The sheets or leaves need to be soaked in cold water before use, and sometimes cooks cut it into small pieces. It softens after several minutes of soaking, squeeze it and then mix with other warm liquid to melt it. Sheets are easy to handle for cooks as no weighting needed, which are commonly seen in hotels and restaurants.
Unflavored or flavored
Unflavored or flavored gelatin, the former also known as plain gelatin which is the pure type while the latter may contain sugar, artificial flavours, colours and other ingredients.
Based on different uses, it can also be generally divided into edible, pharmaceutical, photographic, and industrial grade.
Both edible and industrial grade have similar thickening and gelling effects and their main component is all protein. Their major difference lies in three aspects derived from raw materials.
- Source: edible gelatin is derived from animal skins and bones, while the industrial grade is mainly tanned from leather.
- Price: the cost of the latter is much lower due to the lower cost of the leather.
- Purity: the latter has poorer quality and more impurities. It is strictly forbidden to use industrial grade in medicine and food.
- Uses: industrial grade is mostly used in furniture and printing but forbidden to be used in food as it comes from leather which has a high content of the heavy metal residues- chromium and other harmful chemicals.
Industrial grade almost cannot be distinguished by sensory such as color and taste, but most probably can be tested by the chromium content brought from the leather tanning process.
Put it simply, collagen is a kind of large molecule with an average molecular weight around 300,000, gelatin is a middle molecule with an average molecular weight around 50,000, and 3,000 for gelatin hydrolysate.
Gelatin and collagen are often talked together, both are proteins and similar in amino acid composition. Although these two substances have homology, they are different in physical & chemical properties and uses because of the different manufacturing processes.
Gelatin is the partially hydrolyzed product of collagen through irreversible thermal denaturation and can be called “cooked collagen” as it is obtained by heating collagen for a long time.
Collagen is insoluble in water, whereas gelatin is soluble in warm water. Gelatin is usually used as a gelling agent, thickener or emulsifier in food and pharmaceutical applications, while collagen peptides are functional ingredients that are primarily consumed for the nutraceutical value and health benefits.
What is Collagen?
Collagen generally refers to the undenatured collagen whose natural triple helix structure is preserved to the greatest extent.
Collagen exists in skin, bones, cartilage, tendons, blood vessels, and other connective tissues. It is the most abundant and widely distributed protein in mammals, accounting for about 25%-35% of the total protein content in the body. (3)
As a structural protein of the extracellular matrix, collagen supports and binds everything together in our body.
Collagen molecule is composed of three intertwined identical or different peptide chains through hydrogen bond, van der Waals force and covalent bond. This super-coiled structure makes it very stable.
However, after collagen is partially hydrolyzed to gelatin, its triple helix structure is partly separated and broken. As a result, the formed gelatin gel is more brittle, and with weaker thermal stability.
How is Collagen made?
Animal bones, skins, tendons, and other connective tissues are rich in collagen and are usually used as raw materials to produce collagen with acid or alkali treatment and purification, but without the heating process.
What is Gelatin hydrolysate?
Gelatin hydrolysate or hydrolyzed gelatin, also known as collagen hydrolysate or collagen peptides. It is a group of smaller peptides or even free amino acids, which is a good source of protein and amino acids that can be easily absorbed by the human body.
It is obtained by further enzymatic hydrolysis of gelatin molecules into smaller low molecular weight peptides or even small peptide hydrolysates.
Soluble in cold water but does not have the gelling functionality as the triple helix structure of the gelatin hydrolysate is completely and irreversibly separated and broken.
Gelatin hydrolysate is the most used type of collagen in dietary supplements, functional food & beverage, beauty applications and pharmaceuticals due to the health benefits.
There are sayings that gelatin has the following benefits, but such functionalities may refer to gelatin hydrolysate instead of gelatin.
- Strengthen bones and joints, treat arthritis
- Skin elasticity & tightening
- Promote hair & nail growth
- Help weight loss
With the functional properties such as gelling, emulsifying, aerating, film-forming, and binding, making gelatin irreplaceable in many applications.
Molecular weight ranges from 15,000 to 250,000 depending on the method used (4), CAS number 9000-70-8.
A colorless, or light yellow to yellow translucent powder, granular or sheet, with neutral taste and smell.
Soluble in warm water; soluble in glycerol and propylene glycol; insoluble in cold water, slowly absorb water to swell before bloom.
The most important property of gelatin is to form a transparent thermoreversible gel after being dissolved in hot water.
It causes liquids to gel when cooled and melts to solution form when heated. The thermo-reversibility means the transformation between gel and solution forms can happen again and again without damaging the quality.
The lowest concentration needed to form a gel is about 0.5%.
This property is applied in gummy bears, of which the melting point is very close to the oral temperature of the human body, so it has a soft taste when it melts in the mouth.
As a gelling agent, the gel strength is an important parameter to evaluate the quality of gelatin. Gelatins from different sources have different gel properties. The higher gel strength, higher the molecular weight of the gelatin, and the higher grade.
Bloom value is used to measure the gel strength/firmness. Different applications need different bloom levels. Generally, gelatin with high bloom has a higher firmness and setting temperature.
Bloom value means the force required to depress a standard plunger 4mm into the surface of a 6.67% gelatin sample at 10ºC (50ºF).
The common gel strength of edible gelatin in the market is 100-300 Bloom.
The foaming characteristic means that gelatin can stabilize air into multi-phase emulsions of air, oil and water. It retains air and forming foams of different sizes, thereby producing milky or fluffy products.
We can see this function in the production of marshmallows.
Typically range from 1.5 to 7.5 mPa.s. It indicates the time 100 ml 6.67% gelatin solution needed to go through a standard pipette at 60°C (140°F).
Stable over a wide pH range.
Gelatin is a commonly found ingredient in our food and pharmaceuticals. It is high in protein, free from GMO, no fat, and no carbohydrates.
It is often used as a gelling agent and thickener in food to help solidify, thicken, and stabilize. In pharmaceuticals, it is the most used gelling agent to make the shell of both soft and hard capsules.
Pharmaceutical grade gelatin is an indispensable excipient in the production of hard capsules and soft capsules for its good film-forming and gelling properties.
Gelatin films are mainly used to protect drugs enclosed, to ensure the safe delivery of APIs (active pharmaceutical ingredients), and mask poor taste and odour.
It makes the drugs store easily, maintains the active bioavailability of APIs, and protects them from light, moisture, and oxygen. At the same time, gelatin capsules can quickly dissolve in the gastric acid to ensure the fast drug release in the body.
Hard gelatin capsules are the dosage form for powdered and granulated APIs. Its shells are made of two parts – body and cap that mainly consist of gelatin, opacifying agent (e.g. titanium dioxide), colors, and other ingredients.
Soft gelatin capsules are designed for liquid or semi-solid fillings, such as omega-3 fish oils. They’re a one-piece shell which is composed of gelatin, plasticizer (e.g. glycerol), colors and other ingredients.
For vegetarians and vegans, plant-based alternatives such as HPMC (hydroxypropyl methyl cellulose) and modified food starch may be suitable.
It can also be used as a binder in both wet granulation and direct compression of tablets.
It can be used as a matrix material to embed drops/oils of vitamin A, vitamin E or carotenoids, which are sensitive to light and oxygen, into a free-flowing powder during the vitamin coating process.
Food grade gelatin can act as a gelling agent, stabilizer, binder, emulsifier, film former, or whipping agent in food. The properties of thermo-reversibility and melts in the mouth are welcomed by consumers.
Common food list with gelatin:
- Ice cream
Gelatin is used to hold the shape of dessert and enhance the melting rate of desserts in the mouth. The gelling and water-binding properties make water jellies bright and transparent. It is popular in various jello manufacturing, such as strawberry, strawberry, lemon, mango, and cranberry jello.
In cake and other baked goods, the main purposes are as follows:
- Maintain the texture and make them look more appetizing
- Stabilize cake fillings and coatings
- Improve freeze and thaw stability
Whipped cream and marshmallows
Both whipped cream and marshmallow are aerated confectionery. Gelatin is used to produce fluffy and light texture (increase the volume) and stabilize the whipped effects.
Gelatin is the main gelling agent used for gummy candies. Other hydrocolloids used in the production of gummies usually include pectin, starch, carrageenan, agar agar, sodium alginate and gellan gum.
The most well known gummy candy is the gummy bear. Gelatin contributes to the following features:
- Shiny and crystal transparent appearance
- Elastic texture
- Good chewiness
- Melting tenderness and strong flavor release in the mouth
Gelatin can be used for the clarification or fining fruit juices, beers, and wines by combining with tannins and other ingredients that cause turbidity in them.
Gelatin is removed together with those unwanted substances in the purification process by flocculation or sedimentation.
Gelatin with low bloom value is suitable for this field because it will not gel or gel at a lower temperature.
Make it firm and sliceable.
- Create a smooth mouthfeel, similar to that of fat, so it can be used to reduce fat
- Provide a consistent texture
- Prevent the formation of ice crystals
- Slow melting rate
- Prolong the shelf life
The main purpose of gelatin in yogurt is as a stabilizer to provide a creamy texture and prevent syneresis, which is caused when whey is separated from the curd. It appears to be a water-like film on the surface of the yogurt.
It can be used together with other gums, mainly including pectin, CMC, carrageenan, and etc.
Gelatin can be used to produce low fat and low dairy products by combining with water while ensuring the taste.
For the purpose of foaming, stabilizing, and water-binding.
With the properties of binding, emulsifying, gelling, and stabilizing, gelatin can be used to increase the yield and improve the slice ability in meat products, such as in hams and sausages.
Such as shampoo, face mask, hair thickening agent.
- Ballistic gelatin is a simulant of human muscle tissue and is widely used in trauma ballistics research. In order to better study the human body’s mechanical response when subjected to high-speed impacts (vehicles, blunt objects, bullets, explosive shock waves, etc.).
- Photographic applications: photographic paper (silver print), and X-ray films.
- Electrochemical plating.
- Art: inject the color into a gelatin gel base with art tools (a syringe/needle) to form petals, leaves, and other shapes.
Is gelatin vegan friendly?
No, it is not vegan as there are no plant-based gelatin. All types of gelatin are made from animal collagen, so not suitable for vegetarians.
Agar agar and carrageenan can be gelatin substitutes. Both are derived from seaweed and can be used as a thickener and gelling agent in food.
Is gelatin kosher?
Both bovine and fish gelatin can be regarded as kosher if made from kosher animals that undergo kosher slaughter and processing according to the Jewish law.
Is gelatin halal?
Both bovine and fish gelatin can be accepted as halal as conform to the Islamic Law, while pig gelatin is haram.
Is gelatin gluten free?
Yes, it is gluten free and complies with the FDA’s definition of gluten free, that it does not contain wheat, rye, barley, or crossbreeds of these grains.
Pectin vs gelatin?
Both pectin and gelatin can be used as gelling and thickening agents in food (e.g. gummies and jellies), and sometimes one is an alternative for another. However, they’re totally different in sources, compositions, uses, and benefits.
Pectin is naturally present in apple pomace and citrus peel. Gelatin is made from animal collagen.
Pectin is a polysaccharide, whereas gelatin is an animal protein.
Pectin is vegan while gelatin not. Therefore the former is more acceptable among consumers.
Pectin has a high melting temperature, thus the products made from it cannot dissolve easily in the mouth, and can store at a higher temperature.
Pectin requires sugar and a higher temperature to set.
Pectin is a dietary fiber that is good for lowering blood glucose/blood pressure, while the benefits of gelatin hydrolysate is in strengthening bones and tightening skin.
What’re the substitutes of gelatin?
Agar agar, CMC, carrageenan, pectin, xanthan gum and other gums can be used to replace it in some applications.
Is gelatin natural?
It does not occur free in nature and produced by chemical or enzymatic process.
Now you may have a knowledge of the multifunctional food additive – Gelatin, from the following aspects:
- Common sources: the skins and bones of pig, beef and fish.
- Manufacturing process: treat with acid or alkaline, then cooked with hot water.
- Composition: almost pure protein.
- Types: powder, granular and sheets; with the same function but different use method.
- Difference with collagen and hydrolyzed gelatin.
- Uses: soft and hard capsules, vitamin coating, gummies, marshmallows, desserts, jello, yogurts, ice cream, beer, and etc
- FAQs: is it halal, kosher, vegan, compare with pectin and agar agar, and etc.
What kinds of food labels have you found this ingredient in? Let me know in the comments.
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