An Inquiry into Edible Gelatin

Summary: Edible gelatin is collagen in connective tissue, which is prepared from animal bones and skin. Collagen is the most important protein in the connective tissues of the human body, such as skin, tendons, teeth, bones, and cartilage. How to distinguish between industrial gelatin and edible gelatin? Industrial gelatin and edible gelatin are the protagonists of a series of food safety incidents. The boiling process of industrial gelatin is simpler than that of edible and medicinal gelatin, due to the addition of preservatives such as formaldehyde, there are residues of heavy metals such as chromium and arsenic, and the total number of colonies exceeds the standard. The amount of edible gum used in food is not large, and the role is basically the same as that of household starch, which is mainly used for thickening and increasing stability.

Keywords: edible gelatin; the role of edible gelatin; Edible gelatin application

1. The concept and use of edible gelatin

Edible gelatin is a hydrolysate of collagen, which is a fat-free and high-protein, cholesterol-free, and is a natural nutritious food thickener. Consumption will neither make a person gain weight nor cause a decrease in physical strength [1]. Gelatin is also a strong protective colloid, with strong emulsifying power, and can inhibit the coagulation of milk, soy milk and other proteins caused by gastric acid after entering the stomach, thus facilitating food digestion.

Edible gelatin is a water-soluble protein mixture, collagen in the skin, ligaments, tendons is partially hydrolyzed by acid or alkali or boiled in water, colorless or yellowish transparent crisps or coarse powder, swelling in 35~40 °C water to form a gel (water content is 5~10 times its own weight), is a nutritionally incomplete protein, lacks certain essential amino acids, especially tryptophan, widely used in food and make adhesives, photosensitive negatives, filters, etc. [1]. There will be edible gelatin in yogurt, jelly and other foods, because it has strong water absorption, high viscosity physical and chemical properties, plus it is a fat-free high protein, cholesterol-free, edible gelatin has become a natural and nutritious food thickener.

From the collagen of animals, the collagen obtained from gelatin products can be obtained by partial acid hydrolysis (type A), or partial alkaline hydrolysis (type B), and even by enzymatic hydrolysis and purification.

2. Composition and characteristics of edible gelatin

Edible gelatin is made of fresh cowhide and pig skin as raw materials, using a full set of stainless steel equipment, strictly screening fresh bone skin, and made through dozens of processes such as repeated washing and soaking, degreasing and neutralization, cooking and liquefaction, sterilization and filtration, concentration and drying. The gelatin produced is a tasteless, colorless (slightly light yellow), translucent, hard amorphous substance, which is insoluble in organic solvents, it has strong water absorption and high viscosity, gelatin is a peptide molecular polymer, is a hydrolysate of collagen, so it can be used as an additive, should be kept dry, clean, uniform, and free of inclusions. This product is made of pigs, cows, mules, and horses, and (except for other animal skins) to form juice after impurities, disinfection, and steaming, and then dehydrated and manufactured to form rubber strips, films, and powder granules (generally commonly used powder granular glue) [3]. It should pass through a standard screen with a hole diameter of 4mm, i.e. 5 mesh. This product contains 18 kinds of amino acids and 90% collagen, which is rich in health and beauty effects, and has excellent colloidal protection, surface activity, viscosity, film-forming, emulsion-suspension, buffering, wettability, stability and water solubility.

Edible gelatin can be dissolved in hot water to form a thermoreversible gel, which has extremely excellent physical properties, such as jelly power, affinity, high dispersibility, low viscosity characteristics, dispersion stability, and water holding capacity. Coating, toughness and reversibility, etc., so gelatin is an important food additive, such as as food jelly, stabilizer, thickener, foaming agent, emulsifier, dispersant, clarifier, etc., is widely used.

3. The role of gelatin in food structure

Edible gelatin can be used as a gelling agent, stabilizer, emulsifier, thickener, foaming agent, whipping agent, binder, crystal growth regulator and fining agent in the food industry.

3.1. Edible gelatin as a gelling agent

Edible gelatin and water can form a thermoreversible gel, similar to agar, alginate and pectin, but unlike them, edible gelatin has a low melting point, which is very close to the temperature of the human mouth, while agar gel needs to be chewed because of its high melting point. In addition, edible gelatin jelly does not crystallize in warm and undissolved syrup, and can be reformed after being crushed or heated and dissolved. Jelly made from edible gelatin is more elastic than alginate and pectin jelly, it is better than kraft candy and fruit juice gummies made from egg whites, and it is easier to chew and eat.

Gelatin and agar are mixed to make brittle gelatin food; Edible gelatin is mixed with gum arabic to avoid the jelly melting in the product. Edible gelatin jelly almost does not shrink from dehydration, nor does it take off from candy molds as easily as agar and pectin. Therefore, edible gelatin is widely used in the confectionery industry, and the addition of edible gelatin to toffee, high-grade milk candy, chewing gum, gummy candy, and fruit juice gummies can significantly improve chewing performance, and make these candies tough and non-sticky, and retain a long-lasting taste in the mouth. Taking advantage of this characteristic, edible gelatin is also widely used in canned meat, ham, sausage, beef jelly, ground meat jelly, meat rolls and other foods.