Characterization of sweet whey powder: Functionality, flavor and color.

摘要

Sweet whey powder (SWP), a major by-product of cheese manufacturing, is used in a number of food products. Anecdotally reported variations in functional properties, flavor and color may limit the use of SWP as a food ingredient. In this study, several of these quality parameters were characterized using either commercially available SWP or model systems. The first phase of this work confirmed that such quality variations exist and suggests that manufacturing practices may influence that variation. The flavor of SWP was characterized by sensory and instrumental methods. Volatile analysis indicated that lipid oxidation products such as aldehydes, ketones and Maillard reaction compounds are present. The color of SWP is generally known to brown with storage. In this study, it was found that acidic pH promotes browning via the furfural-intermediate pathway, pH history of liquid whey has a role in SWP browning by favoring the accumulation of browning pigment precursors, and other factors, such as water activity, also influence browning. Additional studies were conducted on the kinetics of SWP browning during storage and the prediction of shelf life. Since numerous factors may affect browning reactions, the influence of selected factors applied to SWP during storage was studied and regression models were developed to predict browning. As a final area of study, this work examined the effect of reducing sugar type on SWP browning, concluding that the presence of moderate levels of galactose or glucose may predispose SAP to brown prematurely. As an overall conclusion from this research, by understanding the functionality, flavor and color of SWP and the factors that may influence the variation in the quality of SWP, dairy processors may be able to alter processing parameters to obtain SWP of improved quality, hence economic value as a food ingredient.