FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY




Effect of homogenisation on selected parameters of skimmed milk, acid curd and acid whey


Under the research study, there was determined the impact of single- (200, 500, 1000 and 2000 bar) and double-stage (200/100 and 500/250 bar) homogenisation on some selected properties of pasteurized skimmed milk, acid curd made from this milk with the use of milk fermentation bacteria and the effect of homogenisation on the transfer of components of milk dry matter to  whey. No statistically significant changes (p > 0.05) were reported in the size of total particles of skimmed milk as a result of single-stage homogenisation at a pressure of 200 bar, while in the  case of double-stage homogenisation at 200/100 bar there was found a significant increase in their size (p ≤ 0.05). A significant reduction in the size of particles was the result of both the single- and the double-stage homogenisation at a pressure > 200 bar. The presence of large particles defined by dv90 and d43 diameters in skimmed milk was probably caused by the impact of  preliminary technological processes on the milk components (centrifugation, pasteurization); the application of homogenisation pressure > 200 bar caused their elimination. It was reported  that the doublestage homogenisation impacted changes in the following colour parameters of skimmed milk: parameter b*, yellowness index, saturation and the difference in total colour and  hue. In the milk tested, there was shown no clear-cut impact of homogenisation pressure on the brightness and the whiteness index. The homogenisation of skimmed milk (regardless of the  homogenisation pressures applied) did not cause the components of milk dry matter to retain in the acid curd and did not impact its firmness. This is confirmed by the results of the  compression test of the examined curd: hardness (0,43 ÷ 0,49 N) and consistency (4,38 ÷ 4,76 N·s), and the composition of whey (fat, protein, lactose, dry matter). The use of homogenisation  does not interfere with the production process of skimmed curd cheeses and it makes it possible to get a product with a curd texture and ingredients retained therein that do not differ from  those contained in the curd produced from a non-homogenised skimmed milk.


skimmed milk, homogenisation, particle size, colour, acid curd, texture