Structural properties before and after ripening of ice cream made with different fat bases

Ice cream is a frozen aerated dessert composed of milk solids, sugars, stabilizers, and fat—this latter being a key component in defining its structural and sensory properties. This study evaluated the influence of four fat sources—low trans vegetable fat (T1), butter (T2), UHT cream (T3), and fresh cream (T4)—on the physical and structural characteristics of ice cream, including overrun, melting resistance, texture, color, and rheology, at different stages of processing (before and after maturation). Oscillatory rheological analysis revealed predominantly elastic behavior (G′ > G″) after maturation in all samples, indicating a stable viscoelastic solid structure. Formulations containing T3 and T1 showed the highest overrun values, indicating greater air incorporation, whereas the butter-based formulation (T2) showed the lowest. Melting resistance followed the order: T3 > T4 > T2 > T1, with the UHT cream formulation exhibiting the greatest thermal stability, likely due to protein denaturation and aggregation induced by high-temperature processing. Texture analysis showed that the T1 formulation required the lowest maximum extrusion force, while T2 required the highest, reflecting an inverse correlation with overrun values. T1 also displayed the most distinctive rheological profile, with the lowest G′ value (~150 Pa) and the highest tan δ (>1.0), indicating predominant viscous behavior., likely due to its specific crystallization behavior and reduced destabilization of the fat globule membrane, which favored the development of a more structured internal network. These findings demonstrate that both the source and processing of fat have a significant impact on the formation of the structural matrix and the final functional properties of ice cream. The results offer technical insights for the development of formulations tailored to specific physical characteristics, optimizing texture, stability, and performance throughout the production process.