Functional properties of 34/ whey protein concentrates

Because of their high lactose and relatively low protein content, 34/ whey protein concentrates (WPC) have received much less attention as food ingredients than their higher protein counterparts. In this investigation 66 samples of 34/ WPC from six different US manufacturers were evaluated for standard functional properties, and representative samples from each of the companies were evaluated further in selected model food systems. In general, the 34/ WPC had good solubility, dispersability, foaming, heat stability, and emulsifying properties. There was no statistically significant difference in the products from the different companies in respect to protein content, solubility at pH 4.6, dispersability, gelation or emulsification characteristics. Statistically significant differences were observed for color, heat stability and foaming properties. These differences, in part, appeared to be related to the degree of stable aggregates more than 1 micron in the samples after hydration. There were no statistically significant correlations between any of the different functional tests for these 61 samples, except that there was a weak negative correlation between color and solubility and gelation properties. All companies had good control of protein content, pH and solubility. Within-company control for other functional properties varied widely from company to company, and would appear to be related to the amount of attention that the company paid to the different functional properties. The 34/ WPC have been evaluated in a number of model food systems, including infant formula, acid beverages, cakes, processed cheese product, yoghurt and whipped topping. Except for cakes, differences in the performance of the 34/ WPC could be associated with products from different companies. One company's product might be best for one application and a different company's product might be best for a different application. Products from all companies performed equally in cakes. The results suggest that 34/ WPC has the potential for successful application in all of the foods tested, and that they are more functional than believed previously.