Comparison of synergistic interactions of yellow mustard gum with locust bean gum or κ-carrageenan

Yellow mustard gum (YMG), a plant mucilage, has been investigated as a natural stabilizer for improving the texture, quality, and shelf life of food products. To expand its applications, synergistic polysaccharide-polysaccharide interactions were examined with two classical gums: κ-carrageenan and locust bean gum (LBG), which have been widely used in food, pharmaceutical and medicinal industries. A rheological approach was used to evaluate gelation characteristics of the two types of binary polysaccharide mixtures during the gelling process. Both types of mixtures demonstrated significant synergisms by forming stronger hydrogels at an equivalent total gum concentration (1% w/v) as their individual gums; however, their gel characteristics and gelation behaviors were different. YMG-κ-carrageenan mixtures formed a firm and elastic gel, but the synergistic effect only occurred at the blending ratio 3 to 7. YMG-LBG mixtures synergistically interacted to form an adhesive and paste-like gel. The gelation of YMG-κ-carrageenan began on cooling and continued during holding at 22 °C while YMG-LBG gel formed quickly after heated mixing at 80 °C and behaved stable regardless of temperature. The synergistic gelation mechanism of YMG-κ-carrageenan was proposed for the first time and illustrated as a result of polymer interactions (both association and segregation) and ion effects. Although further confirmation of the mechanisms is needed, this proposed mechanism would be useful for guiding the use of the synergistic gums regarding their applications in specific processing conditions. Either κ-carrageenan or LBG can be mixed with YMG to act as texturizers, thickeners, stabilizers, gelling agents in food products at an economic concentration.