Comparison of milks processed by the direct and indirect methods of ultra-high-temperature sterilization: V. Denaturation of the whey proteins

SummaryThe distribution of protein nitrogen was determined in milk treated by an experimental ultra-high-temperature (UHT) plant, operating alternatively as an indirect or as a direct heating plant.The extent of denaturation of β-lactoglobulin can be used to assess the relative severity of UHT heat treatments; this criterion was used to compare the indirect and direct arrangements of the plant with each other and with other published results.The time-temperature profiles of the plant were used to calculate the expected extent of denaturation of β-lactoglobulin during treatment of the milk. The results of the calculations are in fair agreement with the analytical results.