Physico-Chemical, Textural and Sensory Evaluation of Emulsion Gel Formulated with By-Products from the Vegetable Oil Industry

The aim of this study was to obtain low fat mayonnaise-like emulsion gels using sesame cake and walnut cake by-products resulting from vegetable oil extraction. The ingredients used to formulate the mayonnaise like emulsion gel samples were corn starch, sesame seed cake (SSC), walnuts seed cake (WSC), lemon juice, sunflower oil, mustard, sugar, salt, gelatin and water. Five different samples were prepared: one control lab sample (M) containing only corn starch and the other ingredients (without SSC and WSC), two samples (SO1 and SO2) with 2 and 4% of SSC (without corn starch and WSC) and two samples (WO1 and WO2) with 2 and 4% of WSC (without corn starch and SSC). Also, an egg-free commercial mayonnaise (CM) was purchased and used for comparison. Physicochemical (fat, protein, moisture, ash, carbohydrate, water activity, emulsion stability, viscosity, density and color), textural (hardness, adhesiveness, springiness, cohesiveness, gumminess and chewiness), and sensory (aspect, color, texture/firmness, flavor, taste and acceptability) attributes of all samples were investigated. The results showed that carbohydrate content decreased in all four seed cakes samples compared to the control sample, while protein and fat content increased in all seed cakes samples, with the largest increases observed in the sesame seed cake samples. It was observed that the CM sample has a carbohydrate content value close to that obtained for the M sample, while the protein content has the lowest value for the CM sample compared to all samples analyzed. The stability of the emulsion gels increased from 70.73% (control sample) to 83.64% for the sample with 2% addition sesame seed cake and to 84.09% for the 2% walnut cake added, due to the coagulation capacity of the added cakes. The type and concentration of oil seeds cake added in emulsion gels affected their textural properties such as hardness, adhesiveness, gumminess, and chewiness. The hardness and adhesiveness of low-fat mayonnaise-like emulsion gels samples decreased with the addition of oil seeds cake. However, the addition of by-products improved the sensory properties of emulsion gels. This study provided a theoretical basis for the food industry's application of oilseed cakes, especially for the development of low-fat mayonnaise.