Emulsifying properties of bitter orange （Citrus aurantium） juice-olive oil salad dressings stabilized with different polysaccharides were investigated. Oil-in-water emulsions （50：50, v/v） were prepared with bitte...Emulsifying properties of bitter orange （Citrus aurantium） juice-olive oil salad dressings stabilized with different polysaccharides were investigated. Oil-in-water emulsions （50：50, v/v） were prepared with bitter orange juice-olive oil in the presence of various concentrations （0.1%-1.0%, w/v） of pectin or guar gum or iota-（t-）carrageenan and then these emulsions were homogenized. Emulsion activity index （EAI） and emulsion stability index （ESI） were determined spectrophotometrically by measuring time-dependent changes in turbidity. Creaming stability of emulsions was followed by visual observation of serum layer with respect to time. Microstructures of emulsions were examined by using polarized light microscopy. The addition of polysaccharides improved emulsion stability and emulsions containing higher amounts of polysaccharide were more stable against creaming. Microscopic observations showed that emulsions containing polysaccharides had small droplets as compared to that of emulsions without polysaccharides and emulsions were flocculated due to the presence of polysaccharides. Larger droplets and creaming were observed when the polysaccharide concentration was not sufficient for coverage.展开更多
文摘Emulsifying properties of bitter orange （Citrus aurantium） juice-olive oil salad dressings stabilized with different polysaccharides were investigated. Oil-in-water emulsions （50：50, v/v） were prepared with bitter orange juice-olive oil in the presence of various concentrations （0.1%-1.0%, w/v） of pectin or guar gum or iota-（t-）carrageenan and then these emulsions were homogenized. Emulsion activity index （EAI） and emulsion stability index （ESI） were determined spectrophotometrically by measuring time-dependent changes in turbidity. Creaming stability of emulsions was followed by visual observation of serum layer with respect to time. Microstructures of emulsions were examined by using polarized light microscopy. The addition of polysaccharides improved emulsion stability and emulsions containing higher amounts of polysaccharide were more stable against creaming. Microscopic observations showed that emulsions containing polysaccharides had small droplets as compared to that of emulsions without polysaccharides and emulsions were flocculated due to the presence of polysaccharides. Larger droplets and creaming were observed when the polysaccharide concentration was not sufficient for coverage.
