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Effect of precipitation temperature and pH on the mechanical strength of batch precipitated acid casein curd

Published online by Cambridge University Press:  01 June 2009

Mark S. Jablonka
Affiliation:
Department of Chemical and Materials Engineering, University of Auckland, Auckland, New Zealand,

Summary

The precipitation stage in acid casein manufacture controls the initial strength of the casein curd, which is an important factor in determining fines losses during processing. A plate extrusion method was used to determine the mechanical strength of casein curd, precipitated batchwise at temperatures from 25 to 53 °C over a pH range of 3·9 to 5·1. Curd strength was determined either immediately after acidulation or after cooling for 2 h at 25 °C. Curd was stronger immediately after acidulation than after cooling and increased in strength as precipitation temperature and pH were increased. Curd precipitated at high temperature and high pH was mechanically strong, had a large particle size, and had high total solids and Ca contents. The relationship between these curd properties is discussed, and it is concluded that Ca retention at high precipitation temperature and pH is largely responsible for the characteristic curd properties under these precipitation conditions.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1986

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References

REFERENCES

Horne, D. S. 1979 The kinetics of the precipitation of chemically modified αsl-casein by calcium. Journal of Dairy Research 46 265269CrossRefGoogle Scholar
Jablonka, M. S. & Munro, P. A. 1985 Particle size distribution and calcium content of batch precipitated acid casein curd: effect of precipitation temperature and pH. Journal of Dairy Research 52 419428CrossRefGoogle Scholar
Jablonka, M. S. & Munro, P. A. 1986 Development of an objective method for assessing the mechanical strength of casein curd. Journal of Dairy Research 53 6168CrossRefGoogle Scholar
Lee, C. H. & Rha, C. K. 1978 Microstructure of soybean protein aggregates and its relation to the physical and textural properties of the curd. Journal of Food Science 43 7984CrossRefGoogle Scholar
Muller, L. L. 1971 Manufacture and uses of casein and co-precipitate. Dairy Science Abstracts 33 659674Google Scholar
Muller, L. L. & Hayes, J. F. 1962 Improved equipment for continuous precipitation of acid casein. Australian Journal of Dairy Technology 17 189193Google Scholar
Pearce, K. N. 1977 The complexometric determination of calcium in dairy products. New Zealand Journal of Dairy Science and Technology 12 113115Google Scholar
Perry, C. A. & Carroad, P. A. 1980 Instrument for texture of small curd cottage cheese and comparison to sensory evaluation. Journal of Food Science 45 798801CrossRefGoogle Scholar
Southward, C. R. & Walker, N. J. 1980 The manufacture and industrial use of casein. New Zealand Journal of Dairy Science and Technology 15 201217Google Scholar
Vogel, A. I. 1961 A Textbook of Quantitative Inorganic Analysis, p. 426. 3rd edn, London: LongmansGoogle Scholar