Surface tension of whole and skim-milk between 18 and 135 °C

Abstract

SummaryThe surface tension (γ) of whole milk (4% fat) and skim-milk was determined in the temperature range 18–135 °C by the drop number method. Measurements were carried out in a temperature-controlled chamber under pressure. Above 90 °C, the mean residence time of the milk at the test temperature was 15 s. Surface tension values were calculated by the Harkins and Brown method, corrections being made to account for the kinetic energy of the drops. The results for whole and skim-milk were not significantly different and the combined data (66 values) could be represented by the equation:γ =1·8 10-4θ2–0·163θ+55·6,(where γ is in mN. m-1 and θ is the temperature in °C) with a residual s.d. of 2·1 mN. m-1 (mean relative error 9·6 % at the 5 % level of significance).

Model for the differentiation of temperature and electric field effects during thermal assisted PEF processing

“…The corresponding relations for milk and apple juice can be found in Bertsch (1983) and Constenla et al (1989).…”

The influence of temperature on the foaming of milk

“…2), is at least partially due to the decrease in viscosity of milk with increasing temperature (Fernandez-Martin, 1972) enabling protein molecules to migrate more rapidly to the air-serum interface of milk foams (Kinsella, 1981;Patino, Delgado, & Fernandez, 1995). Furthermore, the surface tension of the milk decreases with increasing temperature (Bertsch, 1983), and this decrease in surface tension is conducive to improved foamability.…”

An experimental study on pool boiling of milk

“…The following expressions are used for calculating the different physical properties of milk such as specific heat C pl [20], surface tension σ [21], density ρ l [22], viscosity µ l [23], thermal conductivity k l [24], and enthalpy of vaporization h fg [25].…”