Structuro-optical optimization of ethyl cellulose-modified candelilla wax/canola oil oleogels for use as sustainable fat replacers in steamed bread systems

The demand for healthier, sustainable alternatives to conventional solid fats is essential for creating sustainable food systems. This study explored the fat crystal engineering of candelilla wax (CW)/canola oil (CO) oleogels using ethyl cellulose (EC) as a crystal habit modifier. Herein, the aim was to optimize the structural, colorimetric, and mechanical properties of the CW/CO oleogel for use in steamed bread applications. EC concentration (0 % to 10 % (w/w)) was characterized using microscopy, colorimetry, hyperspectral imaging (HSI), X-ray diffraction (XRD), and mechanical testing. Notably, HSI and XRD served as key differentiating tools to decode supramolecular organization and light-scattering phenomena in the oleogels. The 5 % EC oleogel (ST10.0) among the formulations demonstrated the most favorable attributes. ST10.0 exhibited enhanced crystalline morphology, highest yellowness index (46.20 ± 2.17), and a strong reflectance peak at 619 nm (0.919 ± 0.002), indicating superior optical properties. HSI further revealed minimized dark zones and uniform pixel-wise chromaticity. XRD confirmed the rigid and compact molecular packing in ST10.0, evident from the lowest average d-spacing (4.002 Å). Mechanical testing showed that ST10.0 maintained a desirable firmness (548.17 ± 13.50 g) and cohesiveness (2310.44 ± 108.51 g-mm), making it suitable for bakery systems. Incorporation into steamed bread significantly enhanced product dimensions (diameter: 13.00 ± 0.08 cm; height: 4.83 ± 0.04 cm) and crumb aeration. Further, colorimetric evaluation showed improved brightness and diminished browning. These findings demonstrate that ST10.0 oleogel is a promising solid fat replacer with enhanced structural and sensory characteristics, holding significant potential for scalable industrial and clean-label bakery applications.