Submitted to: Journal of Food Processing and Preservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2013
Publication Date: 11/18/2013
Publication URL: http://handle.nal.usda.gov/10113/60518
Citation: Onwulata, C.I., Tunick, M.H., Thomas-Gahring, A.E. 2013. Rapid visco analysis of food protein pastes. Journal of Food Processing and Preservation. DOI: 10.1111/jfpp.12188.
Interpretive Summary: It is important to know in what way proteins in milk change as heat is applied, to predict how different types of proteins mix when combined in foods. For example, some foods may combine egg and soy proteins or egg and milk proteins. This study showed that a rotating mixer called Rapid Visco Analyzer (RVA) can be used to measure the thickness of cooked protein foods. Food manufacturers can use the RVA to know when proteins are properly mixed and cooked.
Technical Abstract: Whey protein isolate (WPI) powders are used in many formulations to boost nutrients. To predict the pasting behavior of proteins, WPI was tested under varying temperatures, using the Rapid-Visco-Analyzer (RVA), under pasting temperatures from 65 to 75 degrees'C, RVA speeds from 100 to 500 rpm, and protein concentrations from 2.5 to 40 percent. The optimal pasting profiles for WPI were obtained at 75 degrees'C, 300 rpm, and 30 percent protein concentration. The concentration of the other food proteins evaluated were: calcium caseinate (CC) 20 percent, egg albumin (EA) 20 percent, soy protein isolate (SPI) 10 percent, and extrusion-texturized whey protein isolates (tWPI) 30 percent. Multiple (12) RVA pasting runs of WPI resulted in a superimposed profile with peak paste value of 1.50 plus or minus 0.3 Pa.s, and a standard error of plus or minus 0.43 Pa.s. Within the specified conditions, the RVA pasting peaks (Pa.s) were: CC (6.2), EA (4.6), SPI (0.6) and tWPI (1.7). Depending on the source of protein, the concentration needed for RVA pasting profile ranged from 5 to 30 percent.