De-mineralized hot water extraction then removes the gelatin from ossein or gel bone. Excess lime is neutralized with the addition of acid. Once the ossein is washed with water to remove impurities it is ready for the “liming process.” Ossein is soaked with one to four percent lime (CaOH2) solution for 35-70 days with agitation weekly. Ossein is the name given to the de-mineralized crushed bones. Typically, fresh bones are crushed, boiled in hot water at 180-250 oF, to remove grease and demineralized with four to six percent strong acid for a period of 5 to 7 days (Garono, et al, 1956). Once the lime is washed off the processing steps for crushed bones and hides are the same (Sakr, 1999). Both hides/skins and bones go through a lime treatment. The hides are chemically dehaired, with a lime/sulphide solution (anywhere from 5-20 weeks) followed by mechanical loosening. All of the chromium is typically not removed. When collagen is taken from chromium-tanned bovine hides, steps are taken to remove the chromium (Rose, 1990). Raw skin is dehaired and degreased before the lime processing occurs. Raw skins and chromium-tanned bovine hides go through alkaline processing for gelatin formation. The gelatin extract is concentrated to 50% solids, sterilized at very high temperatures for short time, extruded, hot air dried, then milled to specific sizes, and blended for various bloom strengths and packaged (Hinterwaldner, 1977a).Īlkaline Process/Bovine Gelatin (Type B Gelatin): The skin is then extracted with hot water and the extract is filtered through an anion-cation exchange column to remove minerals. The acid-treated pigskins are then washed with water to remove impurities. Typically pigskin is degreased and then soaked at a pH of 1 to 4 with a strong acid for 8 to 30 hours (Hinterwaldner, 1977b Keenan, 1994 Cole, 2000 Ledward, 2000). The resulting form is gelatin.įrom Collagen to Gelatin Acid Pretreatment/Porcine Gelatin (Type A Gelatin):Ĭollagen from animals slaughtered at a young age such as those coming from pigs need a mild treatment and thus are subjected to acid hydrolysis. During the transition from collagen to gelatin the bonds holding together the strands of amino acids in the helix begin to break along with various inter- and intramolecular (Schiff base and aldo condensation bonds) and a few peptide bonds (Veis, 1965). The three predominant sources of the collagen used for gelatin manufacturing are from pig sources (Type A gelatin), bovine (Both Type A and Type B gelatin – mainly B), or fish skins.Īs is the case with most polymers, heat coupled with acid or base treatment renders a change in the conformation of the material. There is predominantly a regular repeating sequence of three amino acids within each chain, glycine, proline, and hydroxyproline. Each chain typically contains over 1400 amino acids (Protein Data Bank). Structurally collagen is composed of three long intertwined chains of amino acids (helical polymer – a triple helix). Collagen is a common long fibrous structural protein. Gelatin is produced from the collagen in pigskin, cattle hide, fish skin, or animal bones (including cattle and pig). Kosher gelatin however may still be problematic for Muslim consumption as will be explained later.Ĭonsider what is gelatin and how is it made? Often Kosher foods and Halal foods overlap. Gelatin, like several other products and ingredients, is considered more “Muslim Friendly,” if it is Kosher. “Where does gelatin come from?” and “where is it used?” are pivotal questions that make it so critical to watch out for it in the first place. Often gelatin comes up as one of the poster child ingredients Muslims shy away from.
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