Fractionation of the mixture of
proteins found in milk and whey to form pure, individual dairy
protein fractions might allow individuals with special nutritional needs to tailor their diet to improve health. Ion exchange process chromatography was examined for this purpose using selective elution to release separately the
proteins bound from whey and produce several
protein fractions. Alternatively, bound
proteins were released all at once to make a
whey protein isolate. Prototype beverages containing these
proteins were examined for clarity before and after thermal processing. Beverages containing
whey protein isolate were clear at pH 2-7 before heating, but only beverages at pH <or= 3.0 were clear after thermal processing (88 degrees C, 120 s). Beverages at higher pH were made clear after heating by addition of food-grade
lauryl sulfate, which prevented aggregation of the denatured
proteins formed during thermal processing. Alternatively, thermally processed clear beverages at
pH 3-7 were possible using the
whey protein glycomacropeptide. Because of the balance between sweetness and acidity, beverages with a pH greater than carbonated soft drinks and juices (pH 2.5-3) might remain palatable using less
sugar. Development of high-
protein low-
carbohydrate beverages might provide health benefits for individuals suffering from diabetes,
obesity, and
hypercholesterolemia, especially when these beverages contain dairy
protein fractions known to be high in
essential amino acids and
branched-chain amino acids.