Ready-to-drink (RTD) beverages being marketed to the widest possible consumer base often incorporate some type of protein fortification. For this purpose, whey proteins are frequently an ingredient of choice. High-protein drinks, typically greater than 4% protein, generally are ingested for amino acid replenishment and anabolic muscle-building during and after exercise. Low-protein drinks are typically less than 4% protein and seem to be targeted to mothers of young children as a healthy alternative to carbonated soft drinks.
Whey proteins are very high in essential and branched chain amino acids which are necessary for serum replenishment during exercise and the anabolic period post-exercise. “These proteins are soluble at the pH of the digestive tract and increase blood amino acid levels in a much shorter period of time after ingestion, as compared to other protein sources which must be 'predigested' to first make them soluble,” states Dennis Vosen, technical director at Century Foods International. Also, some of the minor proteins present in ultra-filtered/micro-filtered (UF/MF) whey products have been shown to be important for digestive tract health and also display immunomodulatory characteristics.