Thermal inactivation of chymosin during cheese manufacture

2002 ◽  
Vol 69 (2) ◽  
pp. 269-279 ◽  
Author(s):  
MAURICE G. HAYES ◽  
JORGE C. OLIVEIRA ◽  
PAUL L. H. McSWEENEY ◽  
ALAN L. KELLY
Keyword(s):  
Thermal Inactivation ◽  
Skim Milk ◽  
Inactivation Kinetics ◽  
Swiss Cheese ◽  
Chemical Difference ◽  
Milk Whey ◽  
Milk Clotting ◽  
Cooking Temperature ◽  
Milk Clotting Enzyme ◽  
Cheese Curd

The aspartic proteinase, chymosin (EC 3.4.23.4) is the principal milk clotting enzyme used in cheese production and is one of the principal proteolytic agents involved in cheese ripening. Varietal differences in chymosin activity, due to factors such as cheese cooking temperature, fundamentally influence cheese characteristics. Furthermore, much chymosin is lost in whey, and further processing of this by-product may require efficient inactivation of this enzyme, with minimal effects on whey proteins. In the first part of this study, the thermal inactivation kinetics of Maxiren 15 (a recombinant chymosin preparation) were studied in skim milk ultrafiltration permeate, whole milk whey and skim milk whey. Inactivation of chymosin in these systems (at pH 6.64) followed first order kinetics with a D45.5 value of 100±21 min and a z-value of 5.9±0.3 °C. D-Values increased linearly with decreasing pH from 6.64 to 6.2, while z-values decreased as pH decreased from 6.64 to 6.4, but were similar at pH 6.4 and 6.2. Subsequent determination of chymosin activity during manufacture of Cheddar and Swiss-type cheese showed good correlations between predicted and experimental values for thermal inactivation of chymosin in whey. However, both types of cheese curd exhibited relatively constant residual chymosin activity throughout manufacture, despite the higher cooking temperature applied in the manufacture of Swiss cheese. Electrophoretic analysis of slurries made from Cheddar and Swiss cheese indicated decreased proteolysis due to chymosin activity during storage of the Swiss cheese slurry, but hydrolysis of sodium caseinate by coagulant extracted from both cheese types indicated similar levels of residual chymosin activity. This may suggest that some form of conformational change other than irreversible thermal denaturation of chymisin takes place in cheese curd during cooking, or that some other physico-chemical difference between Swiss and Cheddar cheese controls the activity of chymosin during ripening.

Cheese-making with a vegetable rennet from Cardo (Cynara cardunculus)

1972 ◽  
Vol 39 (3) ◽  
pp. 335-343 ◽  
Author(s):  
F. Vieira de Sá ◽  
Manuela Barbosa
Keyword(s):  
Rheological Behaviour ◽  
Cow’S Milk ◽  
Cynara Cardunculus ◽  
Cheese Making ◽  
Cow's Milk ◽  
Milk Clotting ◽  
Ph Values ◽  
Sheep Milk ◽  
Milk Clotting Enzyme ◽  
Cheese Curd

SummaryThe milk-clotting enzyme found in the flowers of Cardo (Cynara cardunculus) was investigated as to its suitability as a substitute for traditional animal rennet used in cheese-making. The influence of milk pH, temperature and quantity on the clotting activity of this enzyme was studied. Rheological behaviour of cow's-milk and sheep-milk curds, from renneting to cutting, was determined with the Plint cheese curd torsiometer for various Ca contents and pH values. Edam, Serra and Roquefort cheeses were made and the protein breakdown which occurred in the cheese during the ripening period was determined. Animal rennet was used as a control in all the experiments. The enzyme from Cardo was a satisfactory substitute for animal rennet with cow's milk and was even more suitable for sheep's milk. It was found to be a very good clotting enzyme for soft-bodied cheese like Serra, but because of its high proteolytic activity it presented some problems in Edam cheese-making. In Roquefort cheese it gave satisfactory results, but with some loss in yield.

Thermal stability of acid proteinases

2000 ◽  
Vol 67 (4) ◽  
pp. 637-640 ◽  
Author(s):  
MARIE K. WALSH ◽  
XIAOSHAN LI
Keyword(s):  
Milk Fat ◽  
Thermal Inactivation ◽  
Three Dimensional ◽  
Skim Milk ◽  
Rhizomucor Miehei ◽  
Heat Stability ◽  
Cryphonectria Parasitica ◽  
Maximum Activity ◽  
Enzyme Preparations ◽  
Milk Clotting

Milk-clotting enzymes are used during the production of cheese to coagulate the casein, allowing the formation of a three-dimensional network that entraps the milk fat. Commercially available milk-clotting enzymes differ with respect to source, specificity, optimum pH and thermostability. All are acid proteinases that can cleave κ-casein resulting in the coagulation of milk. Chymosin (EC 3.4.23.4) is specific for the Phe–Met bond in κ-casein at the natural pH of milk (6·7). Recombinant chymosin is available commercially from a variety of sources and has a maximum activity at 40 °C. Recombinant chymosins are purified from the fermentation of recombinant strains of Aspergillus niger, Asp. oryzae or Kluyveromyces marxianus. These enzyme preparations are chemically and functionally identical to calf chymosin. Rennets are purified from the abomasum of bovines and can contain from 60 to 100% chymosin with the remainder being primarily bovine pepsin (Wigley, 1996). Microbial proteinases (EC 3.4.23.6) are generally more proteolytic than chymosin, with varying heat stability. These enzymes liberate more non-protein N from casein and can cleave α- and β-casein as well as κ-casein at the natural pH of milk. Acid proteinases from Cryphonectria parasitica are more heat labile than those from Rhizomucor miehei, which are characterized as thermostable (Ernstrom & Wong, 1974).The objective of this research was to characterize milk-clotting enzymes with respect to thermal inactivation in skim milk. This information has applications in milk and whey processing.

Perspectives of using complex milk-clotting enzyme preparations for ripening rennet cheeses production

2019 ◽  
pp. 24-26
Author(s):  
D.V. Abramov ◽  
◽  
D.S. Myagkonosov ◽  
I.N. Delitskaya ◽  
V.A. Mordvinova ◽  
...  
Keyword(s):  
Enzyme Preparations ◽  
Milk Clotting ◽  
Milk Clotting Enzyme

Novel Bacillus Milk-Clotting Enzyme Produces Diverse Functional Peptides in Semihard Cheese

2021 ◽  
Vol 69 (9) ◽  
pp. 2784-2792
Author(s):  
Fanqiang Meng ◽  
Haizhen Zhao ◽  
Fengxia Lu ◽  
Xiaomei Bie ◽  
Zhaoxin Lu ◽  
...  
Keyword(s):  
Milk Clotting ◽  
Milk Clotting Enzyme ◽  
Functional Peptides

Milk-clotting Enzyme from Microorganisms

1971 ◽  
Vol 35 (9) ◽  
pp. 1398-1401
Author(s):  
Juhyun Yu ◽  
Gakuzo Tamura ◽  
Kei Arima
Keyword(s):  
Milk Clotting ◽  
Milk Clotting Enzyme

Milk-clotting Enzyme from Microorganisms

1971 ◽  
Vol 35 (8) ◽  
pp. 1194-1199
Author(s):  
Juhyun Yu ◽  
Gakuzo Tamura ◽  
Kei Arima
Keyword(s):  
Milk Clotting ◽  
Milk Clotting Enzyme

A novel milk-clotting enzyme from Aspergillus oryzae and A. luchuensis is an aspartic endopeptidase PepE presumed to be a vacuolar enzyme

2022 ◽  
Author(s):  
Yoko Takyu ◽  
Taro Asamura ◽  
Ayako Okamoto ◽  
Hiroshi Maeda ◽  
Michio Takeuchi ◽  
...  
Keyword(s):  
Aspergillus Oryzae ◽  
Milk Clotting ◽  
Milk Clotting Enzyme ◽  
Proteolytic Activities ◽  
Homologous Enzyme ◽  
Traditional Fermentation ◽  
Enzyme Source ◽  
Cheese Production ◽  
Milk Clotting Activity ◽  
Aspartic Endopeptidase

Abstract Aspergillus oryzae RIB40 has 11 aspartic endopeptidase genes. We searched for milk-clotting enzymes based on the homology of the deduced amino acid sequence with chymosins. As a result, we identified a milk-clotting enzyme in A. oryzae. We expected other Aspergillus species to have a homologous enzyme with milk-clotting activity, and we found the most homologous aspartic endopeptidase from A. luchuensis had milk-clotting activity. Surprisingly, two enzymes were considered as vacuole enzymes according to a study on A. niger proteases. The two enzymes from A. oryzae and A. luchuensis cleaved a peptide between the 105Phe-106Met bond in κ-casein, similar to chymosin. Although both enzymes showed proteolytic activity using casein as a substrate, the optimum pH values for milk-clotting and proteolytic activities were different. Furthermore, the substrate specificities were highly restricted. Therefore, we expected that the Japanese traditional fermentation agent, koji, could be used as an enzyme source for cheese production.

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