Text Box: 11:50 AM Text Box: CHEMISTRY & NUTRITION Text Box: The interrelationship between carrageenan and milk & soy proteins as demonstrated by the physical characteristics of a retorted, shelf-stable pediatric nutritional beverage Text Box: Cindy Black and Dr. Barringer Text Box: Liquid nutritional beverages provide essential sustenance, but consumers who use these products demand that they look appealing, taste good and are packaged in a convenient container. It is a challenge for food scientists to develop and maintain a quality, shelf-stable product that meets these expectations. Components of the formulation, such as proteins and stabilizers, play a key role in defining the physical quality. A study was completed to evaluate the effect of protein and carrageenan types on the physical parameters of a liquid nutritional beverage. Eighteen batches were manufactured using different proteins (milk protein isolate (MPI), whey protein concentrate (WPC) and soy protein isolate (SPI)) and different carrageenans (kappa, lambda and iota). The batches were analyzed at one month of age for color, viscosity, grain, gelation, whey, creaming, and sediment. Product manufactured with MPI resulted in the lightest color with a target viscosity and minimal defects. Batches containing WPC had the highest grain (except batches with iota) and the darkest color. The SPI resulted in product with the highest viscosity and gelation/whey, but the least sediment. The three carrageenan types also impacted the physical stability characteristics: iota has the lowest viscosity, grain, gelation and highest whey, sediment; lambda has the highest viscosity, grain, gelation and lowest whey, sediment and kappa is an average between the two. None of the carrageenan types had any effect on color or creaming. Further research is needed to assess if these effects can be altered by using different combinations of multiple carrageenans and proteins.