Original scientific paper
The influence of whey protein concentrate on the viscosity of yoghurt, acidophilus and acidophilus yoghurt
Olivera Marić
; "KRAŠ" Prehrambena industrija d.d. Zagreb
Marija Carić
Rajka Božanić
orcid.org/0000-0002-3387-0315
; Prehrambeno-biotehnološki fakultet, Pierottijeva 6, 10000 Zagreb
Ljubica Tratnik
Abstract
In this paper the influence of whey protein concentrates (WPS) with 16.3% of total solids and 10.2% of proteins, added to milk on the viscosity of yoghurt (3% of yoghurt culture); acidophilus (3% culture Lactobacillus acidophilus) and acidophilus yoghurt (2% culture L acidophilus and 1% yoghurt culture) was determined. Fermentation of milk samples (with and without WPC) was performed at 40PC until coagulum formed at pH value about 4.6. During 10 days of storage in refrigerator at 4°C, changes of pH value and sensory properties of fermented beverages, were determined. Viscosity of fermented beverages was measured (the first and the tenth day of storage) using rotatory viscosymeter (HAAKE, VT 500) at 2CPC and applying the shear rate from 0 to 500 ®"^ Chemical composition and acidity of milk samples and mixture of milk with WPC (4:1) used in fermented beverages production, were determined using standard analytical methods. Addition of WPC to milk brought about nearly the same viscosity decrease in all fermented beverages values being similar. After 10 days of storage viscosity change was noticed only in acidophilus yoghurt and yoghurt. However during sensory evaluation the consistency and flavour differences were as well not significant between fermented beverages (with and without WPC), even after 10 days' storage (+4°C).
Keywords
yoghurt; acidophilus; acidophilus yoghurt; whey protein concentrates; viscosity; sensory properties
Hrčak ID:
94986
URI
Publication date:
15.5.1996.
Visits: 1.779 *