Synergistic Interactions of Yellow Mustard Gum with Kappa-Carrageenan
Yellow mustard gum (YMG) is a value-added ingredient derived from yellow mustard seed by-products. It exhibits shear-thinning flow behavior and excellent emulsifying and stabilizing abilities in both oil/water and water/oil systems. These properties remain relatively stable under various pH, temperature, and solute conditions. However, the current extraction technology, involving hot water soaking and ethanol precipitation, limits its commercial production and application. This thesis aimed to explore and demonstrate the commercial potential of YMG by investigating its synergistic gelation blend with κ-carrageenan. Rheology, calorimetry (DSC), and microscopy (Cryo-SEM) were employed to study YMG and its synergistic blends. A scale-up production protocol was developed, utilizing minimal processing steps and no organic solvents. The pilot-scale YMG product exhibited similar chemical composition and rheological properties to the purified YMG obtained through a previous lab-scale method. Moreover, this YMG product effectively encapsulated essential oil blends and provided long-term stability in an oil-in-water system. Synergistic interactions between YMG and κ-carrageenan were observed, differentiating them from the synergistic interaction of YMG with locust bean gum (LBG). YMG-κ-carrageenan (YMG-C) gels demonstrated strong and elastic properties, whereas YMG-LBG gels exhibited adhesive and paste-like behavior. Gelation of YMG-C was induced by cooling, similar to κ-carrageenan, while YMG-LBG gels remained stable throughout the gelation process, forming and stabilizing quickly after heating and mixing. The synergism between YMG and κ-carrageenan stemmed from the compatibility of the two gums, resulting in the formation of a single-phase cooperative gel when κ-carrageenan dominated the system (YMG:κ-carrageenan 3 to 7). The synergistic blend led to stronger gel strength primarily due to polymer interactions between the two gums. YMG did not affect the coil-to-helix transition of κ-carrageenan but participated in its helix aggregation during gel setting. These findings provide valuable insights to support the commercial production and application of YMG as a clean-label natural gum.