Investigation of the Use of Soy Protein Isolate-Cellulose Nanofiber Complex as a Fat Substitute in the Production of a Low-Fat Mayonnaise

In recent years, due to the increased awareness of the risk of cardiovascular diseases induced by the consumption of high-fat diets, remarkable attention has been given to reduce the fat level in foods and produce low-fat products. In this study, the three levels of soy protein isolate-cellulose nanofiber complex gel (5, 15, and 25%) and three levels of cellulose nanofiber: soy protein isolate ratio (1:5, 1:10, and 1:15) in the complex gel, were used as a fat substitute to produce a low-fat mayonnaise. The effect of oil substitution by the complex gel on physicochemical properties (moisture, pH, acidity and physical and thermal stability), texture, color, and sensory properties of the mayonnaise were evaluated. The results showed that rising oil substitution by the complex gel significantly (P<0.05) increased the moisture content and decreased the acidity, and physical and thermal stability of the mayonnaise. All the textural properties of mayonnaise, such as firmness, cohesiveness, consistency, and viscosity index was significantly reduced upon the oil substitution by the gel and this effect was more pronounced in samples containing higher gel concentrations. The color indices (L* and b* values) and sensory properties of the samples were decreased significantly, as well. According to the results of the present study, the soy protein isolate-cellulose nanofiber complex gel at 5% oil substitution, particularly the gel with nanofiber cellulose to protein the ratio of 1:5 has a high potential as a fat substitute to fabricate a low-fat mayonnaise with acceptable physical and thermal stabilities, textural, color, and sensory characteristics.