Walnut oil oleogel constructed by cellulose nanofiber and walnut protein isolate: Structure, rheology...

Cellulose nanofiber (CNF) was used to construct plant oil into viscoelastic oleogel, an innovative alternative to solid and trans-fats, but it was hampered due to strong hornification trend of CNF during thermal dehydration. Walnut protein isolate (WPI) was incorporated to stabilize CNF-based walnut oil emulsion-template and fabricate oleogel. Results demonstrated that the combination of CNF and WPI enabled a stable, less elastic and softer oleogel with higher oil-binding capacity (OBC, >90%) and comparable gel strength (rheological modulus G* of 40-160 kPa), while CNF usage was reduced to 0.6% and small amount (1.0-1.8%) of WPI was required. Complementary stabilization effect, derived from the dual mechanisms of interface adsorption and surrounding phase structuring, contributed to the fortification of OBC, rheological and textural performance of oleogels, while CNF played a dominate role. This study provides a better understanding of the synergistic roles of CNF and WPI in fabricating food colloids.