The effects of whey proteins and homogenization pressure on the stability of concentrated soft drink emulsions

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references (leaves 64-70).Issued also on microfiche from Lange Micrographics.Concentrated beverage emulsions containing 14% canola oil, 20% whey protein concentrate from acid or sweet whey protein concentrate, 10% whey protein concentrate from acid or sweet whey protein concentrate with 10% gum arabic, and 20% gum arabic were prepared. The emulsions were homogenized and stored at 5⁰C for analysis of creaming index, homogenization index, particle size index, particle size distribution, and viscosity. Creaming index was affected by type of emulsifier and homogenization pressure. The CI values of acid whey, sweet whey, or gum arabic emulsions increased when the homogenization pressure was increased from 20 to 60 MPa. However, the CI of the emulsion prepared using sweet whey and gum arabic decreased during storage. There was no significant effect by emulsifier, homogenization pressure, and days of storage on emulsion stability determined by HI. The particle size distribution of the sweet whey emulsion homogenized at 20 and 60 MPa, the acid whey emulsion homogenized at 60 MPa, and the acid whey and gum arabic emulsion homogenized at 20 MPa changed during storage time. These emulsions appeared to have experienced creaming during storage. The size of particles in the emulsions prepared using sweet or acid whey and gum arabic were larger than particles in emulsions prepared using other emulsifiers. There was an increase in the percentage of small particles in these emulsions during storage. Material from loosely associated surface aggregates was probably migrating to the continuous phase of the emulsion. The particle size index of emulsions made from acid whey changed during storage and the change might have been related to the concentration of minerals in emulsions. The viscosity of emulsions prepared using acid whey, acid whey and gum arabic, and gum arabic did not change. Physical characteristics of the particles in these emulsions did not change during storage. The viscosity of acid whey, acid whey and gum arabic, and sweet whey and gum arabic increased when the homogenization pressure was increased from 20 to 60 MPa. The higher viscosity at 60 MPa was probably caused by an increase in the number of particles and the interfacial surface viscosity of particles of emulsions