Effect of curdlan on the physicochemical properties and microscopic morphology of spiced beef during cooking and freezing

This study aimed to establish the functional influence of curdlan (0 %, 1.0 %, 2.0 %, and 3.0 %) on the quality of spiced beef through monitoring changes in cooking yield, textural properties, pH, oxidative stability, and micromorphology during marination, cooking and freezing. The results showed significant enhancements (P < 0.05) of viscosity and absorption yield of the marinade solution as well as the freezing rate of spiced beef upon, increasing the curdlan concentration. At a 2.0 % curdlan addition level, spiced beef showed the maximum tenderness (shear force), increased springiness and elasticity. Meanwhile, the colorimetric values were improved and lipid oxidation (peroxide; malonaldehyde) was consistently reduced during storage up to 14 days, whereas 3.0 % curdlan on day 14 exacerbated oxidation. Scanning electron microscopy and confocal laser scanning microscopy imaging of beef samples treated with 1.0 % and 2.0 % curdlan showed a relatively even distribution of curdlan within muscle fiber bundles, contrasting to 3.0 % curdlan treatment where curdlan accumulated mostly in the gaps between muscle bundles and fibers. Additionally, low-field NMR analysis demonstrated that the inclusion of 2.0 % curdlan significantly increased the immobile water content (P₂₃). In corroboration, sensory analysis indicated that spiced beef treated with 2.0 % curdlan had the highest appearance, juiciness, taste, and flavor scores, suggesting that muscle structural improvement by the curdlan inclusion, optimal at the 2.0 % level, played a principal role in the quality enhancements of marinaded spiced beef.