Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-26T22:37:48.905Z Has data issue: false hasContentIssue false

Effect of pH, calcium concentration and temperature on the evolution of the refractometric signal produced during rennet coagulation of milk

Published online by Cambridge University Press:  01 June 2009

Jozef Korolczuk
Affiliation:
Laboratoire de Recherches de Technologie Laitière, INRA, 35042 Rennes Cedex, France
Jean-Louis Maubois
Affiliation:
Laboratoire de Recherches de Technologie Laitière, INRA, 35042 Rennes Cedex, France

Summary

An industrial refractometer connected to a microcomputer was used to study the rennet coagulation of milk. The amplitude of the refractometer's signal changes during coagulation was about 104 times more important than the resolution of the computerized refractometer. The signal v. time derivatives were calculated and the inflection point time (ti) was correlated with pH, Ca concentration and temperature. The inflection point time was inversely proportional to the rennet and Ca concentrations and the logarithm of the proportionality factor (k) was linearly correlated with pH. The relation between ti and temperature was curvilinear. It is concluded that the refractometer tested could be used for research on the coagulation process.

Type
Original articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1988

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Dalqleish, D. G. 1979 Proteolysis and aggregation of casein micelles treated with immobilized or soluble chymosin. Journal of Dairy Research 46 653661CrossRefGoogle Scholar
Dalqleish, D. G. 1983 Coagulation of renneted bovine casein micelles: dependence on temperature, calcium ion concentration and ionic strength. Journal of Dairy Research 50 331340CrossRefGoogle Scholar
Frentz, R. 1965 [Application of Hartert's thromboelastography to a study of the coagulation of milk.] Lait 45 489508CrossRefGoogle Scholar
Foltmann, B. 1959 On the enzymatic and the coagulation stages of the rennetting process. 15th International Dairy Congress, London 2 655661Google Scholar
Fox, P. F. 1969 Milk-clotting and proteolytic activities of rennet, and of bovine pepsin and porcine pepsin. Journal of Dairy Research 36 427433CrossRefGoogle Scholar
Guthy, K. & Novak, G. 1977 Observations on the primary phase of milk coagulation by rennet under standardized conditions. Journal of Dairy Research 44 363366CrossRefGoogle Scholar
Hardy, J. & Fanni, J. 1981 Application of reflection photometry to the measurement of milk coagulation. Journal of Food Science 46 19561957CrossRefGoogle Scholar
Hardy, J., Fanni, J. & Scher, J. 1985 [A turbidimetric determination of milk coagulation.] Revue Laitière Française No. 441 1318Google Scholar
Johnston, D. E. 1984 Application of polymer cross-linking theory to rennet-induced milk gels. Journal of Dairy Research 51 91101CrossRefGoogle Scholar
Kato, I., Ando, K., Mikawa, K. & Yasui, T. 1980 Action of rennin on casein. III. Effect of αs – and β-casein on the secondary phase. Journal of Dairy Science 63 2531CrossRefGoogle ScholarPubMed
Korolczuk, J., Roignant, M. & Maubois, J. L. 1985 Computer data acquisition of sinusoidally varying stress and strain. Journal of Texture Studies 16 129142CrossRefGoogle Scholar
Korolczuk, J., Maubois, J. L. & Loheac, , 1986 [Examination of the rennin coagulation of milk by refractometric measurement]. Lait 66 100120Google Scholar
Kowalchyk, A. W. & Olson, N. F. 1977 Effects of pH and temperature on the secondary phase of milk clotting by rennet. Journal of Dairy Science 60 12561259CrossRefGoogle Scholar
Libbey, L. M. & Ashworth, U. S. 1960 Spectrophotometric observations on the reaction of rennin with sodium caseinate. Journal of Dairy Science 43 856Google Scholar
Marçais, H. 1965 [Application of thrombelastography to the study of milk coagulation.] Lait 45 241250CrossRefGoogle Scholar
McMahon, D. J., Brown, R. J. & Ernstrom, C. A. 1984 a Enzymic coagulation of milk casein micelles. Journal of Dairy Science 67 745748CrossRefGoogle Scholar
McMahon, D. J., Brown, R. J., Richardson, G. H. & Ernstrom, C. A. 1984 b Effects of calcium, phosphate, and bulk culture media on milk coagulation properties. Journal of Dairy Science 67 930938CrossRefGoogle Scholar
McMahon, D. J., Richardson, G. H. & Brown, R. J. 1984 c Enzymic milk coagulation: role of equations involving coagulation time and curd firmness in describing coagulation. Journal of Dairy Science 67 11851193CrossRefGoogle Scholar
Parker, T. G. & Dalgleish, D. G. 1977 The potential application of the theory of branching processes to the association of milk protein. Journal of Dairy Research 44 7984CrossRefGoogle Scholar
Robson, E. W. & Dalgleish, D. G. 1984 Coagulation of homogenized milk particles by rennet. Journal of Dairy Research 51 417424CrossRefGoogle Scholar
Scott Blair, G. W. & Burnett, J. 1958 a Physical changes in milk caused by the action of rennet. I. Description of apparatus for measuring rigidity moduli and internal viscosities, tests of reliability and some observations on syneresis. Journal of Dairy Research 25 297303CrossRefGoogle Scholar
Scott Blair, G. W. & Burnett, J. 1958 b Physical changes in milk caused by the action of rennet. III. Effects of separation, homogenization and pasteurization and of varying calcium content on the rigidity moduli and viscosities of curd. Journal of Dairy Research 25 457466CrossRefGoogle Scholar
Scott Blair, G. W. & Burnett, J. 1959 Physical changes in milk caused by the action of rennet. IV. Effects of varying rennet concentration and temperature. Journal of Dairy Research 26 5862CrossRefGoogle Scholar
Scott Blair, G. W. & Burnett, J. 1963 An equation to describe the rate of setting of blood and milk. Biorheology 1 183191CrossRefGoogle Scholar
Scott Blair, G. W. & Oosthuizen, J. C. 1961 A viscometric study of the breakdown of casein in milk by rennin and rennet. Journal of Dairy Research 28 165173CrossRefGoogle Scholar
Świa¸tek, A., Kuczera, F. & Kiepacki, J. 1962 [The character of milk coagulation depending on the coagulation enzyme.] 16th International Dairy Congress, Copenhagen B 433441Google Scholar
Tarodo de la Fuente, B. & Frentz, R. 1966 [A thrombelastographic study of the coagulation of milk by rennet: effects of temperature and calcium concentration.] Lait 46 371393CrossRefGoogle Scholar