An assessment of improved functionality of radio frequency dielectric heated nonfat dry milk into model food systems

Abstract

The application of a dry heat processing technology, such as radio frequency dielectric heating (RFDH) on nonfat dry milk (NFDM), has been proven to inactivate pathogens and to alter functional properties. The altered functional properties of RFDH-treated NFDM could produce a valuable, novel ingredient that may improve final product quality when used in other food systems. However, dependent upon the RFDH conditions, whey protein denaturation can occur in low-heat NFDM (LH), which in turn impacts functional properties. To understand how RFDH-treated NFDM influences the functional properties in a variety of food systems, RFDH-treated LH was the milk source in the manufacture of bread, white sauce, and caramels. Low-heat NFDM was RFDH-treated ((heated to 85°C and held for 90 min (85/90) or 180 min (85/180)) and cooled. For bread, white sauce, and caramel, the NFDM samples ((LH, 85/90, 85/180, and high heat (HH)) were directly added into formulations. Three replications were completed and all data were analyzed using SAS statistical software to differentiate amongst the significant means. Within bread, the 85/90 and 85/180 displayed similar physical properties such as loaf volume, crumb firmness, and color properties when compared to HH. In white sauce, the 85/180 functioned similar to HH as these sauces had similar firmness, water-holding capacity, and color (darkness). When formulated within caramels, 85/90 and 85/180 displayed similar water activity, firmness, stickiness, and color properties as caramels produced with HH. Due to the nature of these particular food systems, it is possible that formulating with the RFDH-treated NFDM, will produce better quality finished products when compared to LH.