Gelatin or gelatine (from Latin: gelatus which means "stiff", "frozen ") are translucent, colorless, brittle (dry), tasteless foods derived from collagen obtained from different parts of the animal's body. It is commonly used as a gelling agent in foods, pharmaceutical drugs, vitamin capsules, photography, and cosmetic manufacturing.
The substances containing gelatin or functioning in the same way are called "jelly." Gelatin is an irreversible form of hydrolysed collagen, in which the hydrolysis results in the reduction of protein fibers into smaller peptides, which will have a wide range of molecular weights associated with physical and chemical denaturation methods, based on the hydrolysis process. It is found in gummy candy, as well as other products such as marshmallows, gelatin desserts, and some ice cream, dips, and yogurt. Gelatin for prescription use comes in the form of sheets, granules, or powders. Instant types can be added to food as they are; others must be soaked in water beforehand.
Video Gelatin
Composition and properties
Gelatin is a mixture of peptides and proteins produced by collagen partial hydrolysis extracted from the skin, bones, and connective tissues of animals such as pet cows, chickens, pigs and fish. During hydrolysis, the natural molecular bonds between the individual collagen strands are broken down into more easily reset forms. Its chemical composition, in many aspects, is very similar to its parent collagen. Photographic and pharmaceutical values ​​of gelatin are commonly derived from cow bones and pig skin. Gelatin has proline, hydroxyproline and glycine in its polypeptide chain. Glycine is responsible for closing chain packing. The presence of the proline limits the conformation. This is important for the gelatin properties of gelatin.
Gelatin readily dissolves in hot water and sinks into the gel during cooling. When added directly to cold water, it does not dissolve well. Gelatin is also soluble in most polar solvents. The gelatin solution shows viscoelastic flow and stream birefringence. Solubility is determined by the method of preparation. Usually, gelatin can be dispersed in a relatively concentrated acid. Such dispersions are stable for 10-15 days with little or no chemical change and are suitable for coating purposes or for extrusion into a settling basin.
The mechanical properties of gelatin gel are very sensitive to temperature variations, previous gel thermal history, and amount of time elapsed. This gel exists only in the small temperature range, the upper limit is the melting point of the gel, which depends on class gelatin and concentration, but usually, less than 35 Ã, Â ° C (95Ã, Â ° F) and the lower limit of freezing point where ice crystallizes. The upper melting point is below the human body temperature, an important factor for mouthfeel foods produced with gelatin. The viscosity of the largest gelatin-water mixture when the gelatin concentration is high and the mixture remains cool at about 4 Ã, Â ° C (39Ã, Â ° F). The gel strength is quantified using the Bloom test. Gelatin strength (but not viscosity) decreases when temperatures above 100 Ã, Â ° C (212Ã, Â ° F), or if held at temperatures near 100 Ã, Â ° C for long periods of time.
Maps Gelatin
Production
The amount of gelatine production worldwide is around 375,000-400,000 tons per year (830 ÃÆ'â € " 10 < soup> 6 -880 10 6 Ã, lb/A). On a commercial scale, gelatin is made from a by-product of the meat and leather industry. Most of the gelatin comes from pigskin, pigs, and cow bones, or separate cowhide. Fish by-products can also be used because they remove some of the religious barriers surrounding the consumption of gelatin. The raw material is prepared by different curing, acid, and alkaline processes used to extract dry collagen hydrolysates. This process may take several weeks, and differences in the process have a profound effect on the properties of the final gelatin product.
Gelatin can also be prepared at home. Boiling a certain piece of bone cartilage or meat produces gelatin dissolved into the water. Depending on the concentration, the resulting stock (when cooled) will form the gel or gel naturally. This process is used for aspic.
While many processes exist in which collagen can be converted into gelatin, they all have several of the same factors. Intermolecular and intramolecular bonds that stabilize insoluble collagen should be disconnected, and also, the hydrogen bonds that stabilize the collagen helix must be broken. The process of making gelatin consists of three main stages:
- Pretreatments to make the raw material ready for major extraction steps and to remove impurities that may have a negative effect on the physiochemical properties of the final gelatin product
- The main extraction step, which is usually done with hot water or dilute acid solution as a multistage extraction to hydrolyze collagen into gelatin
- Purification and recovery treatments include screening, clarification, evaporation, sterilization, drying, rutting, milling, and sieving to remove water from the gelatin solution, to mix the extracted gelatin, and to obtain the dry, flat and mixed finish product.
Pretreatments
If the raw material used in the production of gelatin is derived from bone, a dilute acid solution is used to remove calcium and other salts. Hot water or some solvent can be used to reduce the fat content, which should not exceed 1% before the main extraction step. If the raw material consists of skin and skin; reduction in size, leaching, hair removal from the skin, and degreasing is required to prepare the skin and skin for major extraction steps.
Collagen hydrolysis is performed by one of three different methods: acid, alkali, and enzymatic hydrolysis. Acid treatments are particularly suitable for less crosslinked materials such as pig skin collagen and typically require 10 to 48 hours. Alkali treatments are suitable for more complex collagen such as those found in cowhide and require more time, usually weeks. The purpose of alkali treatment is to destroy certain chemical bonds that are still present in collagen. In the gelatin industry, gelatin obtained from raw materials treated with acids has been called A-type gelatin and gelatin obtained from alkali-treated raw materials is called B-type gelatin.
Progress has occurred to optimize the yield of gelatin using enzymatic hydrolysis of collagen. The maintenance time is shorter than necessary for alkali treatments, and results in almost perfect conversion for pure products. The physical properties of the final gelatin product are considered better.
Extraction
After preparation of the raw material, ie, reducing the cross-linkage between the collagen component and removing some impurities such as fat and salt, partially purified collagen is converted into gelatin by extraction with water or acid solution at the appropriate temperature. All industrial processes are based on neutral or acid pH values ​​because although alkali treatments speed up conversion, they also promote the degradation process. Acid extraction conditions are widely used in industry, but acid levels vary with different processes. This extraction step is a multistage process, and the extraction temperature is usually increased in subsequent extraction steps, ensuring minimum thermal degradation of the extracted gelatin.
Recovery
This process includes several steps such as filtration, evaporation, drying, grinding, and sieving. This operation depends on the concentration and also depends on the particular gelatin used. Gelatin degradation should be avoided and minimized, so that the lowest temperature may be used for the recovery process. Most of the recovery is fast, with all the processes done in several stages to avoid damage to the vast peptide structure. The worsening peptide structure will result in a low gel strength, which is generally undesirable.
Usage
Initial history of food applications
The first use of gelatin in food was associated with the English Middle Ages (1400s) when the livestock ferns were boiled to produce the gel. Further commercial developments occurred in 1754 when a British manufacturing patent was issued. Food applications in the US and France during 1800-1900 appear to have formed gelatin flexibility, including the origin of its popularity in the US as Jell-O. In the mid-1800s, Charles and Rose Knox of New York produced and marketed gelatine powder, diversifying appeal and gelatin applications.
Culinary used
Probably best known as the gelling agent in cooking, different types and levels of gelatin are used in various food and non-food products: common examples of gelatin-containing foods are gelatin, trifles, aspic, marshmallow, corn candy and candies such as Peeps, gummy bear, fruit snack, and baby jelly. Gelatin can be used as a stabilizer, thickener, or texturizer in foods such as yogurt, cream cheese, and margarine; It is used, too, in foods that are reduced in fat to simulate mouthfeel fat and to create volume. It is also used in the production of several types of Chinese soup dumplings, especially Shanghainese soup dumplings, or xiaolongbao , as well as Shengjian mantou , fried and steamed dumplings. Patches are both made by combining milled pork with a gelatinous cube, and in the process of cooking, gelatin melts, creating thick, sticky interiors like typical gelatin.
Gelatin is used for clarifying juices, such as apple juice, and vinegar.
Isinglass obtained from the swim pockets of fish. It is used as a fine agent for wine and beer. In addition to jelly hartshorn, from deer horns (hence called "hartshorn"), isinglass is one of the oldest sources of gelatin.
Technical use
- Professional and theatrical lighting equipment uses color gel to change the color of light. Historically, this was made with gelatin, hence the term, color gel.
- Gelatin is usually a pharmaceutical capsule shell to make it easier to swallow. Hypromellose is a vegetarian acceptable alternative to gelatin, but it is more expensive to produce.
- Some adhesives of animals such as glue hides may be unrefined gelatin.
- It is used to hold silver halide crystals in emulsions in almost all photographic film and photographic paper. Despite several attempts, no substitute matches the stability and low cost of gelatin that has been found.
- Used as carrier, coating, or separator for other substances, for example, making it? - because it dissolves in water, so give yellow color on soft drinks containing? -carotene.
- Gelatin is used as a binder on the head of a match and sandpaper.
- Cosmetics can contain variants of non-gel gelatin under the name of hydrolyzed collagen.
- Gelatin was first used as an external surface measure for paper in 1337 and continued as the dominant sizing agent of all European papers until the mid-nineteenth century. In modern times, it is mostly found in watercolor paper, and sometimes in glossy printing paper, artistic paper, and playing cards. It retains wrinkles in crÃÆ'ªpe paper.
Dietary limitations and gelatin substitutes
The consumption of gelatin from certain animals may be prohibited by religious or cultural taboos. For example, halal Jewish and Islamic halal customs require gelatin from sources other than pigs, such as cows (which have been slaughtered according to religious rules) or fish (which they are allowed to consume). The Romans were careful of the gelatin products that might be made from horses, because their culture forbade the consumption of horses. Some companies determine the source of the gelatin used.
Vegans and vegetarians choose not to eat foods containing gelatin made from animals. Likewise, Sikh, Hindu and Jain adat may require gelatin alternatives from sources other than animals, as many Hindus, most Jains and some Sikhs are vegetarians. Others just consider gelatin uncomfortable because of the ingredients used in its production.
Some alternatives to gelatin derived from animals include seaweed extract and carrageenan, and pectin and konjac. Synthetic collagen research is ongoing; in 2011, partial success has been achieved in replicating collagen structures using self-assembling peptides.
The protein content
Although gelatin contains 98-99% protein based on dry weight, but has little additional nutritional value, varies according to source of raw materials and processing techniques.
Amino acids present in gelatin vary, due to various sources and batches, but roughly:
- Glycine 21%
- Proline 12%
- Hydroxyproline 12%
- 10% glutamic acid
- Alanine 9%
- Arginine 8%
- 6% aspartic acid
- Others 22%
Security issues
In 1997, the US Food and Drug Administration (FDA), with support from the TSE Advisory Committee (transmittable spongiform encephalopathy), began monitoring the potential risks of animal disease transmission, particularly bovine spongiform encephalopathy (BSE), commonly known as disease mad cow . An FDA study from that year states: "... measures such as heat, alkaline treatment, and screening can be effective in reducing the level of TSE agent pollution, but scientific evidence is insufficient at this time to show that this treatment will be effective. BSE infectious agents if present in the source material. "On March 18, 2016, the FDA finalized three provisional final rules designed to reduce the potential risks of BSE in human foods. The final rule explains that "gelatin is not considered to be forbidden cattle if produced using specified indigenous industrial processes."
The Scientific Steering Committee (SSC) of the European Union in 2003 stated that the risks associated with cow bone gelatin are very low or zero.
In 2006, the European Food Safety Authority stated that the SSC's opinion was confirmed, that the BSE risk of gelatin from bone was small, and that it recommends removal of a 2003 request to exclude older bovine skulls, brains and vertebrae. from 12 months of the material used in the manufacture of gelatin.
Health effects
In 2011, the European Food Safety Authority Panel on Diet Products, Nutrition and Allergies concluded that "cause-and-effect relationships have not yet formed between the consumption of collagen hydrolyzate and joint maintenance". The 2012 review also found insufficient evidence to support its use for osteoarthritis. In contrast, in 2013, Health Canada approved the label for "hydrolyzed collagen", establishing that labels can make health claims that the amino acid intake of supplements from collagen hydrolyzed "helps reduce joint pain associated with osteoarthritis".
References
External links
Media related to Gelatin on Wikimedia Commons
Source of the article : Wikipedia
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