Background and Objectives: Manipulation of protein-polysaccharide interactions provides an opportunity to control the stability and texture of food emulsions. Proteins are surface-active ingredients and can function as effective emulsifying agents also polysaccharides with polyelectrolytes capacity can impart excellent colloidal stability to emulsion droplet by a combination of electrostatic and steric mechanisms. The aim of this study is production of reduced-fat mayonnaise using electrostatic and covalent of &beta-lactoglobulin and Farsi gum as stabilizer, as well as elimination of cholesterol and reducing application of other stabilizers.

 Materials and Methods: At first, electrostatic and covalent complexes of &beta-lactoglobulin and Farsi gum with dry and wet heat treatment were produced. Then Farsi gum and all of the complexes with 1% wt concentration were used in the mayonnaise. The samples were compared in terms of droplet size distributions, apparent viscosity, firmness, color and microscopic analysis. 

Results: Comparison of mean droplet size of the samples showed that mayonnaise contained dry-heated (for one week at 60 ºC and relative humidity of 75%, 1:1 biopolymer mixing ratio) &beta-lactoglobulin-Farsi gum complex (D1/11) had the smallest size. Mayonnaise containing Farsi gum and W/1:2/6.69 (wet-heated &beta-lactoglobulin-Farsi gum complex with 1:2 biopolymer mixing ratio and pH=6.69) had mean droplet size similar to commercial mayonnaise. Mayonnaise containing Farsi gum showed non-uniform microstructure by microscopy observation. Commercial mayonnaise had the highest apparent viscosity followed by mayonnaise containing Farsi gum. Firmness result also had the same trend (P<0.05). Commercial samples showed significant differences and the highest yellowness compared to others due to the presence of egg.

Conclusions: According to the above results, &beta-lactoglobulin-Farsi gum complexes can be used as emulsifier and stabilizer in mayonnaise and salad dressing.