Preparation and application of soy protein isolate-filled sucrose composite particles in sugar-reduced chocolate via...

Excessive sugar consumption is a major contributor to obesity, diabetes, and cardiovascular diseases, driving the urgent need for effective sugar reduction strategies in food products. This study prepared soy protein isolate (SPI)-filled sucrose composite particles with varying protein contents (4.5%-50%) through freeze-drying-mediated SPI-sucrose assembly. DSC, XRD, SEM, and CLSM analyses showed that increasing SPI content decreased the thermal transition temperature and enthalpy of the composite particles, while the intensity of characteristic sucrose diffraction peaks gradually decreased without a shift in peak positions. The retained peak positions indicated that the sucrose crystalline phase was preserved and that SPI did not substitute for sucrose molecules within the crystal lattice. Meanwhile, the particle Sucrose morphology transformed from relatively dense to loose and porous structures, indicating protein-mediated morphological modulation and surface/interfacial co-assembly of SPI with sucrose-based particles. When applied to chocolate as a sucrose substitute, time-intensity (TI) sensory evaluation demonstrated that at 4.5% protein content, the sweetness integral area (422.5) and peak intensity (7.16) exceeded those of the sucrose control (385.3 and 6.0), achieving both sugar reduction and sweetness enhancement. At 18.4% protein content, sweetness perception (6.07) showed no significant difference from the control (6.0), enabling sugar reduction without sweetness loss. However, at protein contents exceeding 30%, sweetness perception significantly decreased (4.76). This research provides a novel technological approach for developing sugar-reduced foods with significant practical value for addressing health concerns related to excessive sugar intake.