Uses of Proteases in Food Industry
Certain proteases have been used in food processing for centuries and any record of the discovery of their activity has been lost in the midst of time. Rennet (mainly chymosin), obtained from the fourth stomach (abomasum) of unweaned calves has been used traditionally in the production of cheese. Similarly, papain from the leaves and unripe fruit of the pawpaw (Carica papaya) has been used to tenderize meats.
These ancient discoveries have led to the development of various food applications for a wide range of available proteases from many sources, usually microbial.Proteases may be used at various pH values, and they may be highly specific in their choice of cleavable peptide links or quite non-specific. Proteolysis generally increases the solubility of proteins at their isoelectric points.The action of rennet in cheese making is an example of the hydrolysis of a specific peptide linkage, between phenylalanine and methionine residues (-Phe105Met106-) in the k-casein protein present in milk. Calf rennet, consisting of mainly chymosin with a small but variable proportion of pepsin, is a relatively expensive enzyme and various attempts have been made to find cheaper alternatives from microbial sources
These have ultimately proved to be successful and microbial rennets are used for about 70% of US cheese and 33% of cheese production worldwide. The development of unwanted bitterness in ripening cheese is an example of the role of proteases in flavour production in foodstuff. The action of endogenous proteases in meat after slaughter is complex but "hanging" meat allows flavour to develop, in addition to tenderizing it. It has been found that peptides with terminal acidic amino acid residues give meaty, appetizing flavours akin to that of monosodium glutamate.The presence of proteases during the ripening of cheese is not totally undesirable and a protease from Bacillus amyloliquefaciens may be used to promote flavour production in Cheddar cheese. Lipases from Mucor miehei or Aspergillus niger are sometimes used to give stronger flavours in Italian cheese by a modest lipolysis, increasing the amount of free butyric acid
Meat tenderization by the endogenous proteases in the muscle after slaughter is a complex process which varies with the nutritional, physiological and even psychological (i.e., frightened or not) state of the animal at the time of slaughter.Meat of older animals remains tough but can be tenderized by injecting inactive papain into the jugular vein of the live animals shortly before slaughter. Proteases are also used in the baking industry.
Certain proteases have been used in food processing for centuries and any record of the discovery of their activity has been lost in the midst of time. Rennet (mainly chymosin), obtained from the fourth stomach (abomasum) of unweaned calves has been used traditionally in the production of cheese. Similarly, papain from the leaves and unripe fruit of the pawpaw (Carica papaya) has been used to tenderize meats.
These ancient discoveries have led to the development of various food applications for a wide range of available proteases from many sources, usually microbial.Proteases may be used at various pH values, and they may be highly specific in their choice of cleavable peptide links or quite non-specific. Proteolysis generally increases the solubility of proteins at their isoelectric points.The action of rennet in cheese making is an example of the hydrolysis of a specific peptide linkage, between phenylalanine and methionine residues (-Phe105Met106-) in the k-casein protein present in milk. Calf rennet, consisting of mainly chymosin with a small but variable proportion of pepsin, is a relatively expensive enzyme and various attempts have been made to find cheaper alternatives from microbial sources
These have ultimately proved to be successful and microbial rennets are used for about 70% of US cheese and 33% of cheese production worldwide. The development of unwanted bitterness in ripening cheese is an example of the role of proteases in flavour production in foodstuff. The action of endogenous proteases in meat after slaughter is complex but "hanging" meat allows flavour to develop, in addition to tenderizing it. It has been found that peptides with terminal acidic amino acid residues give meaty, appetizing flavours akin to that of monosodium glutamate.The presence of proteases during the ripening of cheese is not totally undesirable and a protease from Bacillus amyloliquefaciens may be used to promote flavour production in Cheddar cheese. Lipases from Mucor miehei or Aspergillus niger are sometimes used to give stronger flavours in Italian cheese by a modest lipolysis, increasing the amount of free butyric acid
Meat tenderization by the endogenous proteases in the muscle after slaughter is a complex process which varies with the nutritional, physiological and even psychological (i.e., frightened or not) state of the animal at the time of slaughter.Meat of older animals remains tough but can be tenderized by injecting inactive papain into the jugular vein of the live animals shortly before slaughter. Proteases are also used in the baking industry.
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