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New equation for prediction of water activity in unripe cheese

Published online by Cambridge University Press:  01 June 2009

Pascual López
Affiliation:
Department of Food Science and Technology, Veterinary Faculty, University of Córdoba, 14005 Córdoba, Spain
Andrés Marcos
Affiliation:
Department of Food Science and Technology, Veterinary Faculty, University of Córdoba, 14005 Córdoba, Spain
María A. Esteban
Affiliation:
Department of Food Science and Technology, Veterinary Faculty, University of Córdoba, 14005 Córdoba, Spain

Summary

The water activity of fresh cheese made from cows', ewes' and goats' milk, as well as curd cheese and whey cheese, responds to the equation aw = 0·9719−0·0044[NaCl] + 0·0041 pH, with a square of multiple correlation coefficient R2 = 0·95. This equation was obtained by multiple regression analysis of data point sets of the variables x (g NaCl/100 g moisture), y (pH) and z (water activity, aw) determined as the average of values provided by six samples of each unripe product. Application of this equation to 30 individual samples of unripe dairy products investigated yielded calculated aw values within ±0·005 and ±0·002 aw units of the experimental water activities in 86·7% and 53·3% of the samples, respectively. These results are closer to the experimental values than those provided by earlier predictive equations.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1990

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References

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