A pulse protein product, which may be an isolate, produces heat-stable solutions at low pH values and is useful for the fortification of acidic beverages such as soft drinks and sports drinks without precipitation of protein. The pulse protein product is obtained by extracting a pulse protein source material with an aqueous calcium salt solution to form an aqueous pulse protein solution, separating the aqueous pulse protein solution from residual pulse protein source, adjusting the pH of the aqueous pulse protein solution to a pH of about 1.5 to about 4.4 to produce an acidified pulse protein solution, which may be dried, following optional concentration and diafiltration, to provide the pulse protein product.