The present invention provides a protein composition comprising a milk basic protein fraction； and at least one stabilizer selected from the group consisting of soybean polysaccharides, xanthan gum, pectin, gum arabic, gum ghatti, carrageenan, locust bean gum, sodium caseinate, lecithin, and carboxymethylcellulose. The protein composition significantly improves the heat resistance of the milk basic protein fraction. The present invention achieves heat treatment of a protein composition and food, beverage, feed, and pharmaceutical comprising such a protein composition at a temperature exceeding 90ø C. without deactivation of the milk basic protein fraction.
