Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/25/2005
Publication Date: 12/29/2005
Citation: Onwulata, C.I., Tomasula, P.M. 2005. Improving functionality of whey protein concentrates from different sources. Journal of Dairy Science. Vol. 1 (1) 1-8, 2006.
Interpretive Summary: Whey, a byproduct of the cheesemaking process, is concentrated by processors to make whey protein concentrates (WPC) and isolates (WPI). Only 50% of whey proteins are utilized in foods. Attempts to use WPC from different manufacturers to fortify extruded puffed snack food products made from corn meal have been difficult. The problem may be that variations in the properties of WPC are caused by differences in manufacturing conditions that yield products with different particle sizes. Our studies evaluated the impact of various particle size distributions of six WPC products purchased from five different manufacturers on the functional properties: solubility and foam volume. By separating the larger particles from the smaller ones using a sieve, and more closely matching the particle sizes, more uniform solubility and foam volume were observed, for all WPC from different manufacturers. This method of improving functionality, by sieving, was compared to the traditional method of blending WPC from many manufacturers. Though blending averages the functionality of the WPC, sieving to closely match particle sizes produced predictable functionality. The ability to maintain uniform functional properties will allow for the development of more nutritious extruded products.
Technical Abstract: The nutritional appeal and physical functional properties of whey proteins have increased their level of use in various food products. Fractionation technologies based on ultrafiltration have created whey protein concentrates (WPC) with protein contents ranging from 35 to 80%. However, their functional properties for a particular protein content can vary widely and may depend on processing history, particularly drying. Because of this variability in functional properties the amount of WPC used in formulated foods is kept to a minimum to reduce its effects on the overall quality of the foods. This study was carried out with six commercial WPC with 80% protein content (WPC80) to compare sieving and blending as methods of reducing variations in solubility, gel strength, foam volume and stability of solutions of WPC80. There were significant differences (p<0.05) in the functional properties between the sieved or blended WPC80 samples. Sieving to reduce particle size of WPC80 below 150 microns increased solubility up to 50% for the least soluble samples (p<0.05). Blending all six WPC80 from different manufacturers averaged the solubility values, but sieving was better for improving gel strength and foaming volume for below average WPC80.