The aim of this work was to investigate the influence of several carboxymethylcellulose hydrocolloids addition on the rheological properties of whey model systems as well as sucrose & sorbitol & water solutions. Measurements were done by rotational viscosimeter, Brookfield DV-III at 20 °C. The rheological parameters were determined by Ostwald and Reiner™s power-law model. The results of variance analysis showed that all investigated sources of variation (model solution composition, type of hydrocolloids and freezing process) had a significant influence on the rheological parameter (consistency coefficient). Due to the interaction of hydrocolloid and whey proteins or minerals the viscosity of the model solutions prepared with ultrafiltrated whey dropped substantially. Freezing process increased the viscosity of whey solutions, while the viscosity of solutions prepared with water did not change significantly.
Authors:R. Božanić, Lj. Tratnik, Z. Herceg, and O. Marić
Cow and goat milk samples supplemented with milk powder, whey protein concentrate and inulin and without supplementation were fermented with Lactobacillus acidophilus La5. At the end of fermentation, the highest viable count was found in the supplemented samples, especially in those containing whey protein concentrate. Inulin did not show a notable influence on the bacterial count of samples. During 9 days of storage, the viable count, rheological characteristics and sensory properties of the samples were determined. All goat acidophilus milks had lower pH value and higher viable count of L. acidophilus La5 than the cow acidophilus milks did.