THE EFFECT OF BOILING ON THE VISCOSITY AND PROTEIN CONTENT OF COW MILK PUBLISHEDMihaela OSTAN, I. GOGOAŞĂ, Olga-Alina RADA, B. BAUL, Mihaela FERICEAN, Mihaela CAZACU, Mihaela PETCU, Iuliana CREŢESCU
Due to their chemical composition and their high assimilation degree, milk and dairy products play an important part in rational human nutrition, being one of the most readily accessible sources of animal protein. More than 200 compounds have been found in milk, some in large quantities (water, fats, carbohydrates, and proteins), others in very small quantities, but all of them are intercorrelated and play a very important role in the technology of dairy products. The aim of the present paper is to highlight the effect of boiling on the correlation between viscosity and protein content, analysing fresh milk and boiled milk, respectively. Ten samples were analysed (5 samples of fresh milk and 5 samples of boiled milk), all taken from healthy cows. The chemical composition of milk was determined with a MilkoScan S54B, while the viscosity was determined with the help of Ostwald viscometer. The results were processed statistically with the ANOVA software programme and the differences to p<0.05were considered statistically significant. Viscosity is a biophysical parameter that can be used for assessing the protein content in milk. The results revealed positive correlation between these two parameters, both in fresh milk (r=0.5148), and in boiled milk (r=0.5021). The results also highlighted decreased dynamic viscosity in boiled milk.
cow milk, boiling, viscosity, protein content