열처리로 야기되는 우유 유청 단백질의 반응

Using differential scanning calorimetry (DSC), changes underwent by a mixture of α-lactalbumin (α-La) and β-lactoglobulin (β-Lg) during heat treatment were studied, yielding useful information for the dairy industry. Rusults of the DSC showed that the heat denaturation temperature of the holo-α-La was higher than that of apo-α-La, suggesting holo-α-La`s greater stability. The denaturation temperature of a mixture of holo-α-La and β-Lg was also slightly lower than that of holo-α-La alone. The denaturation temperature of an apo-α-La and β-Lg mixture was higher than that of holo-α-La and β-Lg, suggesting that the heat stability of apo-α-La was increased by β-Lg. Based on these results, it is possible to conclude that a mixture of holo-α-La and β-Lg is more inensively affected by an increase in temperature than other samples, and that free sulphydryl groups seem to take part in this heat-induced denaturation.