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Aug 21-2024
Unlocking the Benefits of Hard Shell Gelatin Capsules in Pharma
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If you have ever closely read the ingredient labels on gummy candies, capsules, or dietary supplements, you have likely come across two familiar terms: bone gelatin and skin gelatin. Both originate from collagen and serve as gelling, thickening, and stabilizing agents. So, why are they categorized as two distinct products, and what difference does it actually make?
Neither is the right choice for every application. Choosing between bone gelatin and skin gelatin comes down to your product requirements. Skin gelatin often has an advantage when you need a light color and clear gel. Bone gelatin is worth considering when you want consistent performance and faster setting. The right choice depends on your product, budget, and dietary or religious requirements.
This article takes about 8 minutes to read and explains the differences to help you choose the right gelatin.
Before diving into the details, we need to cover the basics: what are they? Both are proteins produced through the partial hydrolysis of collagen. Collagen is the tough structural protein that maintains the integrity of the animal body, widely found in skin, bones, tendons, and connective tissue. When collagen is treated with acid or alkali and then heated in water, its tightly wound fibers loosen and dissolve. Through purification and drying, gelatin is finally obtained. Qualified gelatin powder dissolves in hot water and forms a gel upon cooling.
The names refer to the raw materials:
Bone gelatin: Extracted from animal bones, commonly cattle, pig, and fish bones.
Skin gelatin: Made from animal skin or hides, most often pigskin and cattle hides. Skin and scales from deep-sea or freshwater fish are also used to make specialty gelatin.
Further reading: Is Gelatin Made from Bone? A Complete Guide.
Beyond the raw material, the industry often classifies and purchases gelatin by its processing method:
Type A gelatin: Produced using acid pretreatment, usually with hydrochloric or sulfuric acid. Some manufacturers use phosphoric or nitrous acid. Pigskin and fish gelatin are usually Type A.
Type B gelatin: Produced using alkaline treatment, usually with calcium hydroxide (lime) or sodium hydroxide. Bovine hide gelatin and bone gelatin are commonly Type B, although some companies also produce acid-treated bone gelatin.
These classifications overlap, but they describe different things. "Bone" and "skin" identify the raw material; "Type A" and "Type B" identify the production process. Both bone and skin gelatin can be made using either process.
We covered how they got their names earlier. Now let's dive deep into the differences in their production processes. Bone and animal hide raw materials have vastly different properties, and the main distinction in manufacturing lies in the pretreatment stage.
The vast majority of bone dry weight consists of minerals, primarily calcium phosphate, while collagen makes up a relatively small fraction. To extract collagen, manufacturers first remove minerals, following these key steps:
A. Washing and Degreasing: Bones are crushed and rinsed with water. Hot water removes fat and leftover meat debris.
B. Demineralization: Crushed bones are soaked in dilute acid. The acid dissolves calcium and phosphates, leaving soft, porous material rich in collagen — this is ossein.
C. Ripening: Ossein is soaked in lime or acid solution to loosen collagen fibers. Lime treatment typically takes several weeks.
D. Gel Extraction: Hot water is added in multiple batches with gradually rising temperatures. The first extraction yields gelatin with the highest bloom strength. Subsequent batches produce gelatin with progressively lower bloom strength.
E. Purification and Drying: The gelatin solution is filtered, deionized, concentrated, sterilized, dried, and milled into the final product.
Animal hides contain almost no minerals, so demineralization is not required. The main production challenge is removing fat and loose tissue from hides (especially pork skin), with washing and degreasing as the core steps.
A. Trimming and Washing: Hair, loose meat tissue, and impurities are removed.
B. Degreasing: Washing separates fat. Residual fat causes cloudy finished gelatin and off-flavors.
C. Ripening: Pork skin is generally acid-soaked for several hours up to two days. Thick, dense cowhide requires lime ripening for 3 to 7 weeks.
D. Gel Extraction, Purification and Drying: These steps are identical to those for bone gelatin.
Raw materials set the baseline, but final quality hinges on process control. Well-controlled facilities can produce high-quality gelatin regardless of whether they use bone or hide feedstock. Poorly managed operations may yield low-bloom, dark, cloudy gelatin no matter which raw material they use. When you compare suppliers, ask about process control and test data, not just the source name.
Functional properties are the traits that decide how gelatin behaves in your product. Here are the ones that matter most.
Bloom strength: Bloom is the standard measure of gel strength. It is the force, in grams, needed to press a small plunger 4 mm into a gel made at 6.67% concentration and aged at 10°C for about 17 hours. A higher Bloom number means a firmer gel. Both bone and skin gelatin can be made across a wide range, roughly 80 to 300 Bloom. Source does not lock in a number. Extraction conditions and blending do.
Viscosity: This is how thick the gelatin solution is when warm. It affects how a mix pours, coats, or whips. Viscosity depends on molecular weight, which depends on the process. Both types can be made in low, medium, and high viscosity grades.
Clarity and color: Skin gelatin, especially pigskin and well-processed hide gelatin, is often lighter in color and clearer in solution. Bone gelatin can have slightly more color and a little more haze, because bone contains more minerals and trace impurities, even after purification. Modern purification narrows this gap a lot, but it can still show up in clear jellies.
Ash and mineral content: Ash is the mineral residue left after burning a sample. Bone gelatin tends to have somewhat higher ash than skin gelatin. For most uses this is minor. For crystal-clear products or tight pharmaceutical specs, it can matter.
Taste and odor: Properly manufactured gelatin of both types is nearly odorless. Poorly cleaned raw material, in either case, can leave a faint meaty smell.
Melting and setting: Gelatin gels are thermoreversible. They melt when warm and set when cooled. The melting point is close to body temperature, which is why gelatin melts in your mouth. Fish gelatin melts at a lower temperature than mammal gelatin, which makes it softer. This is one reason fish gelatin is not a straight swap for bovine or porcine gelatin.
Quick Overview
This quick table breaks down the functional differences in 30 seconds.
Property | Bone Gelatin | Skin Gelatin |
Common raw materials | Cattle and pig bones | Pigskin, cattle hides, fish skin and scales |
Main pretreatment | Acid demineralization, then conditioning | Degreasing, then conditioning |
Typical process type | Mostly Type B | Type A or Type B |
Achievable Bloom range | About 80–300 | About 80–300; fish skin gelatin is usually lower |
Clarity | Good, can be slightly less clear | Often very clear |
Color | Darker than skin gelatin | Usually very light |
Ash content | Usually somewhat higher | Usually lower |
Melting behavior | Melts near body temperature | Melts near body temperature; fish gelatin melts lower |
Typical uses | Capsules, marshmallows, dairy desserts, tablets, general food applications. | Clear gummies, jellies, premium candies, capsules, tablet coatings, specialty applications. |
Halal/kosher certification | Eligible when made from compliant bovine materials | Bovine hide gelatin: yes, with certification.; pigskin is prohibited; fish gelatin depends on certification. |
Vegetarian suitability | No | No |
The table above briefly lists typical uses for these two types of gelatin. We will now expand on the applicable fields for bone gelatin and hide gelatin, so you can quickly apply this knowledge to your work and business.
Gummies and jellies. Clarity and texture matter most. For crystal-clear gummies, go with skin gelatin in a medium-to-high Bloom range. For colored or opaque gummies, slight haziness won’t show, so price becomes the main factor.
Marshmallows and aerated candies. The gelatin has to trap and hold air. Bloom strength and viscosity matter more than the raw material source. Either type works; just choose a grade that delivers the foam stability you need.
Dairy and desserts. For yogurt, mousse, panna cotta, and cream-based desserts, both types can give you a smooth, even set. Focus on a neutral flavor, choose a low-odor grade, and test it in your recipe.
Hard and soft capsules. Capsule production calls for consistent Bloom and viscosity, low ash, and tight microbial limits. Hard capsules typically use medium-to-high Bloom gelatin, while soft capsules usually run a bit lower. Both bone and skin gelatin are used, and blending the two is common to hit exact specs. Be sure to choose capsule-grade gelatin that meets the pharmacopeia standards in your market. Related reading: Why Gelatin Is the Preferred Material for Hard Capsules?
Tablets and pharmaceutical uses. Gelatin serves as a binder, coating, and stabilizer. Pharmaceutical-grade gelatin must meet strict standards for purity, heavy metals, and microbial content. Compliant quality and traceability documentation matter more than the raw material source.
Meat products and aspics. Clarity is less of a concern here, so price and gel strength come first.
Specialty and low-melt needs. If you want a softer melt in the mouth, fish gelatin is an option. Keep in mind that its gel strength is usually lower.
Quick Selection Guide
For very high clarity and a glossy appearance, start with skin gelatin.
For consistent performance when haze is not a concern, start with bone gelatin.
For specific Bloom and viscosity requirements, prioritize gelatin that meets those specifications rather than focusing only on the source.
For religious or dietary restrictions, verify the source and third-party certification first.
Whichever you choose, test it in your formulation. Sugar, acid, and heating conditions can all affect gelatin's performance.
Their nutritional profiles are very similar. On a dry basis, gelatin contains roughly 85–90% protein and almost no fat or carbohydrates. It is rich in glycine, proline, and hydroxyproline. In collagen, one out of every three amino acids is glycine. Gelatin is not a complete protein; it lacks tryptophan and has low levels of some other essential amino acids. While it can contribute dietary protein, it cannot serve as your sole protein source.
Bone gelatin and hide gelatin show only minor differences in amino acid composition. Slight variations exist between animal sources, but these are not large enough to give one a meaningful health advantage over the other. Purified bone gelatin contains almost no bone minerals, so it should not be relied on as a calcium supplement.
There are widespread claims that gelatin and collagen support skin, joint, nail, and gut health. Some studies on collagen peptides indicate potential benefits for skin elasticity and joint comfort, but research is still evolving and findings are inconsistent. The vast majority of these studies use hydrolyzed collagen peptides — not regular gelatin. Treat marketing claims with caution. Consult a healthcare provider if you have any medical conditions.
⚠️ Important: Gelatin ≠ collagen peptide. Gelatin is partially hydrolyzed, while collagen peptide is fully hydrolyzed. Collagen peptide dissolves in cold water and will not form a gel. Choose gelatin if you need gelling functionality.
Food safety matters to both consumers and brand buyers. The following points apply to consumers and B2B purchasers.
Animal disease safety: Bovine gelatin raises concerns about bovine spongiform encephalopathy (BSE), or mad cow disease. Reputable manufacturers use bones and hides from healthy animals, exclude high-risk tissues, and source materials from approved regions. Ask suppliers for traceability records and food safety certificates. Recommended reading: Is Bone Gelatin Safe for Human?
Halal: Halal gelatin must come from permitted animals slaughtered according to halal requirements, and production must avoid contact with prohibited substances. Pigskin gelatin is not halal. Bovine bone and hide gelatin can qualify with proper certification. Further reading: What Is Halal Gelatin?
Kosher: Kosher rules impose strict requirements on animal species and processing. Porcine gelatin does not meet kosher requirements. Bovine gelatin requires the appropriate certification, and fish gelatin has its own requirements. Read more: What Is Kosher Gelatin?
Vegetarian and vegan diets: Neither bone nor skin gelatin is vegetarian or vegan. Plant-based gelling options include pectin, agar, carrageenan, and modified starch.
Allergens and labeling: Fish gelatin is derived from fish and must be identified on labels under regulations in most countries.
Quality standards: Food-grade gelatin must comply with food safety regulations. Capsule- and pharmaceutical-grade gelatin must meet pharmacopeial standards.
No. Bloom strength depends on manufacturing processes, extraction steps, and blending. Both bone gelatin and hide gelatin can be produced to hit the same Bloom range. Buyers should follow the Bloom and viscosity values listed on the specification sheet. End consumers can get this information by asking the seller or reviewing the product datasheet.
Under suitable conditions, products with matching Bloom strength and viscosity are generally interchangeable, but sample testing is mandatory first. Differences in finished-product clarity, color, and mouthfeel may appear. Always complete formulation trials before full-scale production switchover.
No. Gelatin is partially hydrolyzed collagen and capable of forming gels. Collagen peptide is fully hydrolyzed. It will not gel and dissolves quickly in cold water. Explore our gelatin and collagen peptide product lines.
Bloom range, viscosity, ash content, light transmittance (clarity), microbial specifications, heavy metal test results; raw material source, available certifications, batch consistency, and custom formulation capability.
When selecting bone or hide gelatin, working with a supplier that offers a wide product portfolio and professional technical support simplifies your selection process. Shandong Hengxin Biotechnology Co., Ltd. produces food-grade, pharmaceutical-grade, and capsule-grade bovine bone gelatin and cowhide gelatin. We hold Halal, ISO, Kosher, FDA, BRCGS and other relevant certifications, with an annual capacity of 36,000 metric tons. Custom specifications for Bloom, viscosity and other parameters are available. Share your product application with us, and our technical team will match you with the right grade. Visit our website for quotations.
