Papain, also known as papain, is a protein hydrolase found in papaya (Carieapapaya):
1. Basic Properties
Chemical properties: The molecular weight of papain is 23406. which consists of a single peptide chain containing 212 amino acid residues. Its active center contains cysteine, which belongs to mercapto protease and can also be called cysteine protease. The appearance of papain is white to light yellow powder, slightly hygroscopic, soluble in water and glycerol, aqueous solution is colorless or light yellow, sometimes creamy white, almost insoluble in organic solvents such as ethanol, chloroform and ether.
Activity conditions: papain can decompose protein in acidic, neutral and alkaline environment, the most suitable pH value is 67 (generally 39.5 can be), also has a role in neutral or acidic, isoelectric point (pI) of 8.75. In addition, the most suitable temperature for papain is 5565 ° C (generally 1085 ° C can be), heat-resistant, in 90 ° C will not be completely inactivated, but inhibited by oxidizing agents, reducing substances. However, it is inhibited by oxidizing agents and can be activated by reducing substances.
2.Functional properties
Papain can decompose the peptide bond in protein, decompose it into smaller peptide or amino acid, and has the effect of decomposing fat, starch, cellulose and pectin. Specifically:
Break down proteins: Papain can hydrolyze the carboxyl terminus of arginine and lysine in proteins and peptides, and preferentially hydrolyze those amino acids with two carboxyl groups at the N-terminal end of the peptide bond or the peptide bond of aromatic L-amino acids.
Promotes lipolysis: Papain helps to improve digestion and absorption.
Hydrolyze starch: Papain can hydrolyze starch to dextrin and disaccharide under certain conditions.
Hydrolysis of cellulose: Papain can hydrolyze cellulose in plant cell walls, which is beneficial to the absorption of nutrients.
Degradation of pectin: pectin is a kind of polysaccharide compound in plant tissues, papain has certain degradation effect on it.
3. The field of application
Papain is widely used in many fields because of its high efficiency, safety and natural characteristics:
Food industry: Papain is often used as tenderizer, clarifier and digestive aid in the food industry. For example, in meat processing, papain can hydrolyze muscle proteins and collagen to soften the meat and improve its tenderness and taste. In addition, papain can also be used in beer to combat cold, hydrolyze proteins in beer to avoid turbidity caused by refrigeration. At the same time, papain can also be used in the preparation of cereal pre-cooking, hydrolysis of proteins and the production of meat spices, as well as to promote the decomposition of gluten in cookies to make the finished product fluffy.
Pharmaceutical industry: Papain is used in the pharmaceutical field to treat inflammation, indigestion, chronic gastritis and other digestive disorders due to its ability to help break down and absorb proteins.
Cosmetic industry: Papain has exfoliating and whitening properties and is often used in masks and exfoliating products to help remove dead skin cells and promote skin cell renewal.
Other industries: Papain can also be used in feed, daily chemical, leather and textile industries.