Papain, applications

Irrespective of the descaling effect, development of a soft lustre depends on application of a softener. These experiments were positive in demonstrating the possibility of descaling the fibres and in perceptibly improving lustre under mild conditions. In particular, it was shown that papain is effective at the remarkably low concentration of 50 mg/1, showing a high degree of specificity after chlorination. 

The value of proteases in cleansing tissue wounds has been appreciated for several hundred years. Wounds were sometimes cleansed in the past by application of protease-containing maggot saliva. Nowadays, this is usually more acceptably achieved by topical application of the enzyme to the wound surface. In some cases, the enzyme is formulated in an aqueous-based cream, and in others it is impregnated into special bandages. Trypsin, papain, collagenase and various microbial enzymes have been used in this regard. 

Plant Proteases. These include the well known proteases papain, bromelain and ficin. Most plant enzymes are available as comparatively unpurified powder extracts, although papain is notable for being available in a stabilized and purified liquid form. Prospects for increased supply of plant enzymes, in response to greater use in traditional applications or for new processes, depend on several factors. Tlie influence of cultivation conditions, growth cycle and climate requirements make new supplies long term projects. 

Cleanse the wound prior to application with wound cleanser or saline. For papain-containing products, avoid cleansing with hydrogen peroxide solution. Aerosol Shake well. Hold upright and approximately 12 inches from the area to be treated. Press valve and coat wound rapidly. Wound may be left unbandaged or a wet dressing may be applied. Apply 2 to 3 times daily, or as often as necessary. To remove, wash gently with water. 

Another typical enzyme application in the production of beer is the use of proteases, such as papain or laccases in chill-proofing, which is the prevention of haze formation that can occur at low temperatures during or after the maturation of beer. Finally, to... 

Another major application of the plastein reaction is nutritional improvement of proteins by the incorporation of limiting amino acids (8). A plastein containing approximately 7% methionine was produced from soy protein hydrolyzate and L-methionine ethyl ester in the presence of papain. This material was shown to be utilized as a source of methionine in the rat, producing a PER of 3.38 when incorporated into soy protein diets to give a methionine level of 2.74% of protein. 

Crude papaya latex, usually called papain, has found a number of industrial applications. It has been used in brewing, meat tenderization, flavor production. 

The use of papain in meat tenderization [70] is almost completely restricted to the United States. A number of techniques have been described (preslaughter as well as post slaughter administration) but are not always very successful. In all cases, papain action does not occur before the cooking of the meat and therefore the result is influenced by many factors other than the actual method of application. It has also been aiguedthat the use of papain in meat tenderizes, toothpaste, beer, and fruit juices is the main reason for the higher incidence of systemic allergic reactions after injection of chymopapain for treatment of sciatica in North America than in Europe. 

With a series of applications to well-known food products, we tested the suitability of the proteinaceous surfactants prepared from gelatin by the papain-catalyzed attachment of L-leucine n-alkyl esters. Using each of these surfactants we tried to prepare snow jelly, ice cream, mayonnaiselike food, and bread. 

Inhibitors of Thiol and Carboxyl Proteases. Thiol proteases are inactivated by peptide chloromethyl ketones (30) and other alkylating agents. Peptide diazomethyl ketones are much more selective reagents since they do not react with serine proteases as do chloromethyl ketones. Diazoketones have been applied to papain and cathepsin B (48) thus far and it appears that they should be applicable to most thiol proteases. Specificity should be obtainable by changing the peptide sequence of the inhibitor to match that of the enzyme being studied. 

More recently, covalent chemical modification has been used as a powerful tool to enhance the functionality and stability of enzymes, for example, the covalent link of flavin to papain turned a protease into an oxido-reductase [107]. The use of this methodology was rekindled as a result of the explosion in the interest in commercial and synthetic applications of enzymes [108]. As a consequence, enzymes with new properties such as stability at extreme pH conditions, temperature, or solubility in organic solvents are being generated. 

Proteolytic (protein-cleaving) enzymes also have applications in consumer products. For example, papain (from papaya extract) serves as a meat tenderizer. It cleaves the fibrous proteins, making the meat less tough. 

Source. Enzymes for food applications come from all three kingdoms plant, animal, and microbial. Traditionally used plant and animal enzymes are the plant proteases such as papain, ficin and bromelain, plant amylases from malt, and animal rennin which is used in cheese manufacture. Microbial cells are the usual and most promising future source of industrial enzymes. Estimates of the number of microorganisms in the world tested as potential sources of enzymes fall around 2% with only about 25 organisms, including a dozen or so fungi, currently used for industrial enzymes. 

Papain The purified proteolytic substance derived from the fruit of the papaya Carica papaya L. (Fam. Caricaceae). Produced as a white to light tan, amorphous powder or a liquid soluble in water (the solution is usually colorless or light yellow and somewhat opalescent), but practically insoluble in alcohol, in chloroform, and in ether. Major active principles (1) papain and (2) chymopapain. Typical applications used in the chillproofing of beer, in the tenderizing of meat, in the... 

Application and Principle This procedure is used to determine the proteolytic activity of papain, ficin, and bromelain. The assay is based on a 60-min proteolytic hydrolysis of a casein substrate at pH 6.0 and 40°. Unhydrolyzed substrate is precipitated with trichloroacetic acid and removed by filtration solubilized casein is then measured spectrophotometri-cally. 

Figure 10-24 Effect of Immobilizing on the pH Optimum of Papain. Source From H.H. Weetall, Immobilized Enzymes and Their Application in the Food and Beverage Industry, Process Biochem., Vol. 10, pp. 3-6, 1975.

Medicinal Uses. One of the earliest medicinal applications of the thiol proteases was the use of fig latex as an anthelmintic agent 16, 17). In more recent times papain has been used as a digestive aid in the treatment of dyspepsia and gastric distress. Its usefulness in this respect derives from the fact that papain remains active under acid conditions and is resistant to attack by pepsin. The intraperitoneal injection of sterile solutions of papain has proved to be effective in preventing post-operative adhesions. Papain is sometimes referred to as a T io-logical scalpel because of its specific proteolytic action on dead tissue without affecting live tissue. For this reason it serves as a very useful debridement in the treatment of bums and the removal of scar tissue. When used in combination with antibiotics, it has proved to be effective for topical treatment of ulcerating and infected lesions. 

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