WHEY PROTEIN BIGEL AS A MILK FAT REPLACER IN CREAM CHEESE: DEVELOPMENT AND CHARACTERIZATION

The replacement of conventional fats with structured lipid systems has emerged as a promising strategy for modifying the nutritional composition of dairy products while maintaining their technological properties. Among these systems, bigels combine a structured oleogel and a hydrogel, enabling the modulation of texture, stability, and composition. Therefore, this study aimed to develop different bigel formulations, evaluate their technological performance based on instrumental color and texture properties, identify Bigel 02 (60:40 oleogel-to-hydrogel ratio) as the most suitable formulation, and evaluate its application as a total milk fat replacer in cream cheese. Three bigel formulations were prepared using an oleogel composed of canola oil structured with beeswax and a hydrogel formulated with water and whey protein concentrate, at oleogel-to-hydrogel ratios of 70:30, 60:40, and 50:50. The bigels were characterized by instrumental color and texture profile analyses. Regarding color, no significant differences were observed in lightness (L*) among the formulations, whereas significant differences were observed for a*, b*, chroma, and hue angle. The oleogel-to-hydrogel ratio significantly affected the texture properties of the bigels. Among the evaluated formulations, Bigel 02 (60:40) exhibited the most suitable balance between the structured phases, combining favorable color characteristics with mechanical properties compatible with a spreadable dairy matrix. Based on these characteristics, Bigel 02 was selected for application in cream cheese as a total milk fat replacer. Cream cheese was prepared using pasteurized milk, with the conventional milk fat replaced by the selected bigel, followed by acid coagulation through the addition of lactic acid until reaching a pH of approximately 4.6. After coagulation, the curd was drained and processed to obtain the final product. The cream cheese formulations were characterized by physicochemical composition and texture profile analyses and compared with a conventional formulation. The application of Bigel 02 as a total milk fat replacer resulted in a cream cheese with physicochemical and technological characteristics comparable to those of the conventional formulation. Moisture and ash contents were maintained, while protein content increased, which may be attributed to the incorporation of whey protein concentrate into the hydrogel phase. No significant differences were observed in lipid content or texture profile between the formulations, indicating that the selected bigel allowed the total replacement of milk fat while maintaining important characteristics related to consistency and spreadability. Furthermore, the use of canola oil as the lipid source of the oleogel represents a potential nutritional advantage due to its higher proportion of unsaturated fatty acids compared with milk fat. Overall, the results indicate that whey protein-based bigels are a promising alternative for the total replacement of milk fat in cream cheese, acting as a structured lipid system capable of maintaining the technological characteristics of the product while modifying its nutritional composition.