Mixed Gels of Fresh White Cheese (Twaróg) with Gelatin

Mixed gels based on fresh white cheese (twaróg) and type A gelatin were prepared to investigate their rheological, microstructural, surface, and storage-related properties and to examine possible interactions between casein and gelatin. Selected gels underwent a blending/aeration treatment that simultaneously reduced particle/cluster size and incorporated air. Increasing gelatin concentration was associated with stronger viscoelastic and textural responses. Because total solids were held constant, increasing the gelatin concentration also decreased the casein fraction; therefore, the observed changes reflect changes in the relative proportions of the two protein components as well as the addition of gelatin. ATR-FTIR spectra showed band shifts consistent with changes in the local molecular environment, but these shifts do not establish specific casein–gelatin interactions or changes in casein secondary structure. The blending/aeration treatment was associated with changes in gel microstructure, lower surface roughness, and a lower water contact angle. Turbiscan profiles showed optical changes during 14 days of refrigerated storage. The milled gel containing 2% gelatin had the lowest final TSI among the measured profiles; because only one independently prepared sample per formulation was measured, these comparisons are descriptive and do not establish statistically significant differences in stability or product shelf life. The mixed gels may have potential for refrigerated curd-cheese snack products, although further product-scale validation is required.