Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-28T16:26:16.090Z Has data issue: false hasContentIssue false
  • English
  • Français

Measurement of milk clotting activity by rotational viscometry

Published online by Cambridge University Press:  17 March 2011

Mandy Jacob ,
Martin Schmidt ,
Doris Jaros  and
Harald Rohm
Mandy Jacob
Affiliation:
Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany
Martin Schmidt
Affiliation:
Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany
Doris Jaros
Affiliation:
Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany
Harald Rohm*
Affiliation:
Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, 01069 Dresden, Germany
*
*For correspondence; e-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Standard method for the determination of the activity of milk coagulants is the rotating bottle method, where clotting time is defined as the time when visually observable flocculation starts. Aim of this study was to verify whether it is possible to determine milk clotting time by rotational viscometry. Using three different coagulants and reconstituted milk of different pH and temperature, flocculation time and viscosity in steady shear was determined, and milk gelation was monitored by small amplitude oscillating shear rheometry. The results show that, independent of pH and temperature, milk clotting time is related to an apparent viscosity of 7·24±0·45 mPa.s, indicating that rotational viscometry can be used for the screening of flocculation time with an accuracy of approximately 6%.

Keywords

Milkclottingviscositycasein micelles
Type
Research Article
Information
Journal of Dairy Research , Volume 78 , Issue 2 , May 2011 , pp. 191 - 195
Copyright
Copyright © Proprietors of Journal of Dairy Research 2011

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

ADPI (American Dairy Products Institute) Standards for grades of dry milk, including methods of analysis. Bulletin 916, revised 2009. Elmhurst, IL, USA: American Dairy Products InstituteGoogle Scholar
Bencini, R 2002 Factors affecting the clotting properties of sheep milk. Journal of the Science of Food and Agriculture 82 705–719Google Scholar
Guthy, K & Novak, H 1977 Observations on the primary phase of milk coagulation by rennet under standardized conditions. Journal of Dairy Research 44 363–366CrossRefGoogle Scholar
Guthy, K, Auerswald, D & Buchheim, W 1989 Electron microscopic and viscosimetric studies of the primary phase of rennet coagulation of milk. Milchwissenschaft 44 560–563Google Scholar
Horne, DS 1998 Casein interactions: casting light on the black boxes, the structure in dairy products. International Dairy Journal 8 171–177Google Scholar
Horne, DS 2003 Casein micelles as hard spheres: limitations of the model in acidified gel formation. Colloids and Surfaces A: Physicochemical and Engineering Aspects 213 255–263.Google Scholar
Huppertz, T & de Kruif, CG 2007 Rennet-induced coagulation of enzymatically cross-linked casein micelles. International Dairy Journal 17 442–447Google Scholar
IDF (International Dairy Federation) 1993 Dried milk and dried cream – Determination of water content. IDF 26A: 1993Google Scholar
ISO (International Organization for Standardization) 2001 Milk – Determination of nitrogen content – Part 1: Kjeldahl method. ISO 8968–1: 2001Google Scholar
ISO (International Organization for Standardization) 2002 Milk and milk products – Microbial coagulants – Determination of milk clotting activity. ISO 15174: 2002Google Scholar
ISO (International Organization for Standardization) 2006 Milk and milk products – Ovine and caprine rennets – Determination of milk clotting activity. ISO 23058: 2006Google Scholar
ISO (International Organization for Standardization) 2007 Milk – Determination of total milk-clotting activity by bovine rennets. ISO 11815: 2007Google Scholar
Jaros, D, Seitler, K & Rohm, H 2008 Enzymatic coagulation of milk: animal rennets and microbial coagulants differ in their gelation behaviour as affected by pH and temperature. International Journal of Food Science and Technology 43 1721–1727Google Scholar
Klandar, AH, Lagaude, A & Chevalier-Lucia, D 2007 Assessment of rennet coagulation of skim milk: A comparison of methods. International Dairy Journal 17 1151–1160Google Scholar
Kopelman, IJ & Cogan, U 1975 Determination of clotting power of milk clotting enzymes. Journal of Dairy Research 59 196–199Google Scholar
Lomholt, SB & Qvist, KB 1997 Relationship between rheological properties and degree of k-casein proteolysis during renneting of milk. Journal of Dairy Research 64 541–549Google Scholar
Lopez, MB, Lomholt, SB & Qvist, KB 1998 Rheological properties and cutting time of rennet gels. Effect of pH and enzyme concentration. International Dairy Journal 8 289–293Google Scholar
Mellema, M, Leermalers, FAM & de Kruif, CG 1999 Molecular mechanism of the renneting process of casein micelles in skim milk, examined by viscosity and light-scattering experiments and simulated by model SCF calculations. Langmuir 15 6304–6313Google Scholar
Nájera, AI, de Renobales, M & Barron, LJR 2003 Effects of pH, temperature, CaCl2 and enzyme concentrations on the rennetclotting properties of milk: a multifactorial study. Food Chemistry 80 345–352CrossRefGoogle Scholar
Scott-Blair, GW & Burnett, J 1963 A simple method for detecting an early stage in coagulation of renneted milk. Journal of Dairy Research 30 383–390CrossRefGoogle Scholar
Sommer, HH & Matsen, H 1936 The relation of mastitis to rennet coagulability and curd strength of milk. Journal of Dairy Science 18 741–748CrossRefGoogle Scholar
Walstra, P, Wouters, JTM & Geurts, TJ 2006 Dairy Science and Technology. Boca Raton, FL: CRC PressGoogle Scholar
van Hooydonk, AC & Olieman, C 1982 A rapid and sensitive high-perfomance liquid chromatography method of following the action of chymosin in milk. Netherlands Milk and Dairy Journal 36 153–158Google Scholar

Jacob Supplementary Movie

Jacob Supplementary Movie

Download Jacob Supplementary Movie(Video)
Video 17.2 MB