Izvorni znanstveni članak
The influence of goats milk on viscosity and microbiological quality of yoghurt during storage
Rajka Božanić
orcid.org/0000-0002-3387-0315
; Prehrambeno-biotehnološki fakultet, Pierottijeva 6, 10000 Zagreb
Ljubica Tratnik
Olivera Marić
Sažetak
In this work the influence of long life goat's and cow's milk, with and without milk powder addition, on rheological properties and microbiological quality of yoghurt during storage were investigated. The goat's milk had higher protein, fat and ash content, but lower total solids content (8.77%). For this reason goat's milk samples were enriched with double quantity of milk powder (2%) so the chemical composition this two types of milks were not significantly different. The fermentation of goat's milk samples was about 50 minutes longer than of cow's milk (about 5,40 hours). The goat's yoghurt, in spite of high milk powder addition, had softer consistency, lower viscosity, and higher acidity compared to cow's yoghurt, during all time of storage. Viable microorganisms count in yoghurt samples increases during storage and a third day of storage was maximal (logN=8.60-9.03/ml). On the ninth day microorganisms viable count was approximately equal to microorganisms viable count after fermentation (logN=8.36-8.51/ml). In all yoghurt samples, during storage, viable count of streptococcii was about 5% higher in relation to viable count of lactobacilii, except ninth day of storage when more lactobacilii was detected. Sensory evaluation showed lower scores of goat's yoghurt samples (16.4-18.8) in compared to cow's yoghurt samples (18.1-20.0).
Ključne riječi
goat's yoghurt; viscosity; microbiology; sensoric evaluation
Hrčak ID:
94742
URI
Datum izdavanja:
5.5.1998.
Posjeta: 1.738 *