Review article
Possibilities of implementing nonthermal processing methods in the dairy industry
Irena Jeličić
; Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb,
Rajka Božanić
Ljubica Tratnik
Katarina Lisak
Abstract
In the past two decades a lot of research in the field of food science has focused on new, non-thermal processing methods. This article describes the most intensively investigated new processing methods
for implementation in the dairy industry, like microfiltration, high hydrostatic pressure, ultrasound and pulsed electric fields. For each method an overview is given for the principle of microbial inactivation, the obtained results regarding reduction of microorganisms as well as the positive and undesirable effects on milk composition and characteristics. Most promising methods for further implementation in the dairy industry appeared to be combination of moderate temperatures with high hydrostatic pressure, respectively, pulsed electric fields and microfiltration, since those treatments did not result in any undesirable changes in sensory properties of milk. Additionally, milk treatment with these methods
resulted in a better milk fat homogenization, faster rennet coagulation, shorter duration of milk fermentations, etc. Very good results regarding microbial inactivation were obtained by treating milk
with combination of moderate temperatures and high intensity ultrasound which is also called a process of thermosonification. However, thermosonification treatments often result in undesirable
changes in milk sensory properties, which is most probably due to ultrasonic induced milk fat oxidation. This article also shortly describes the use of natural compounds with antimicrobial effects such as bacteriocins, lactoperoxidase system and lysozime. However their implementation is limited for reasons like high costs, interaction with other food ingredients, poor solubility, narrow activity spectrum, spontaneous loss of bacteriocinogenicity, etc. In addition, principles of antimicrobial effect of microwaves and ultraviolet irradiation are described. However their implementation in the dairy industry failed mostly due to technical and commercial reasons.
Keywords
milk; high hydrostatic pressure; ultrasound; pulsed electric fields; microfiltration
Hrčak ID:
55150
URI
Publication date:
2.7.2010.
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