05 December 2011 - OVH.net

Special Issue 9405 - Monograph on the significance of pathogenic
microorganisms in raw milk
by IDF Group of Experts A10/11 – Bacteriological quality of raw milk
It is increasingly recognized that the hygienic quality of milk has an important
effect on the health of consumers and the quality of the product, and is therefore
of great commercial importance. The greatest foodborne disease hazard now
appears to be pathogenic microorganisms. This monograph covers the most
important microorganisms (bacteria, yeasts and moulds, and viruses), and
discusses the characteristics, procedures for isolation and identification, the
mechanisms of contamination, incidence, significance for man, and aspects of
control and prevention.
Available in the format of a photocopy
Date: 1994 - Pages: 215 - Paper: 61.97
Special Issue 9501 - Heat-induced changes in milk
Second edition (Revision of Bulletin 238/1989)
Edited by P.F. Fox (Ireland) - Twenty chapters compiled by Group F17 of IDF
Chapter 1: Heating methods have been developed which retain as many as
possible of the good organoleptic and nutritive properties of raw milk during heat
treatment. Heating processes – pasteurization, thermization, sterilization – and
equipment – systems for milk pasteurization, UHT-heating systems, sterilization
in the package – are examined.
Chapter 2: A general survey on the thermodynamics and kinetics of reactions,
and how to make practical use of such information is presented. The effect of
temperature is discussed using the Arrhenius equation and the Eyring equation;
it is stressed that the Eyring equation should be used for protein denaturation.
Examples of reactions that occur in milk are given as illustration.
Chapter 3: This chapter first discusses heat-induced chemical changes, which are
mainly due to reactions of fatty acid residues. The physical changes considered
are coalescence, creaming, disruption and aggregation.
Chapter 4: Although protein denaturation of whey protein can be induced by
a variety of agents, thermal denaturation is of greatest industrial significance.
Methods used to evaluate the thermal denaturation of whey protein and the
thermodynamics and kinetics of such a reaction are examined. The effects of
industrial heat treatments on whey proteins in dairy systems and alternative
treatments to avoid whey protein denaturation are discussed.
Chapter 5: A review is given of current knowledge of the principal changes
induced in casein on heating over the temperature range 0-150°C. The
interactions of casein and whey protein on heating mixtures of purified proteins
or skim milk are described. The significance of these interactions in the heat
coagulation of milk, particularly the occurrence of a maximum and a minimum in
the heat coagulation time-pH profile, is discussed briefly.
Chapter 6: The basic physical chemistry of the milk salt system, as presently
understood, is considered, particularly in relation to phase separation of calcium
phosphate and the interaction with casein. Application of the phase rule to milk
allows the phases and phase boundaries to be more clearly defined. Theories
of crystal nucleation, growth and inhibition are used to explain the strong
interaction of casein with calcium phosphate and the very marked, but almost