Introduction
Papain is a sulfhydryl (-SH) endopeptidase possessing both protease and esterase activities. It exhibits broad substrate specificity and strong hydrolytic capability toward animal and plant proteins, peptides, esters, and amides. Additionally, it possesses synthetic capabilities, allowing it to synthesize protein-like substances from protein hydrolysates. It is soluble in water and glycerol; aqueous solutions are colorless to pale yellow, sometimes appearing milky white. It is virtually insoluble in organic solvents such as ethanol, chloroform, and ether.

Characteristics
Papain appears as a white to pale yellow amorphous powder (which is somewhat hygroscopic) or as a liquid. It is soluble in water and glycerol; aqueous solutions are colorless to pale yellow, sometimes appearing milky white. It is virtually insoluble in organic solvents such as ethanol, chloroform, and ether.

Properties

The optimal pH for papain is 5.7 (though it generally functions within the 3–9.5 range), and it remains active under neutral or slightly acidic conditions; its isoelectric point is 18.75. The optimal temperature is 55–60°C (generally effective between 10°C and 85°C); it exhibits strong heat stability and does not completely lose activity even at 90°C. Its activity is inhibited by oxidizing agents and activated by reducing agents. Enzyme product obtained by drying without clarification is classified as crude enzyme.

FAQs 

Q:Is your Papain food grade? 

A:Yes, our Papain is food grade and suitable for a variety of food applications. 

Q:What is the CAS number of Papain? 

A:The CAS number is 9001-73-4. 

Q:What are the main applications of Papain? 

A:Meat tenderizer 

Baking and brewing industry 

Dietary supplements 

Cosmetics (skin care, exfoliation) 

Pharmaceutical preparations 

Q:How should Papain be stored? 

A:Store in a cool, dry place, away from direct sunlight and moisture. Keep tightly sealed after use. 

Q:Is Papain suitable for vegetarians/vegans? 

A:Yes, Papain is a plant-based enzyme and suitable for vegetarian and vegan products. 

Q:Does your Papain have any certifications? 

A:Our Papain can be supplied with Halal, Kosher, ISO, or other certifications upon request. 

Q:Is Papain safe for people with papaya allergies? 

A:People with papaya allergies should avoid Papain, as it may trigger allergic reactions. 

Q:Can you provide COA, MSDS and other documents? 

A:Yes, COA (Certificate of Analysis), MSDS (Material Safety Data Sheet), and other technical documents are available upon request.