Physicochemical properties and intermolecular interactions of a novel diacylglycerol oil oleogel made with ethyl cellulose as affected by γ-oryzanol

Abstract

With an aim to prepare a novel formula for healthy oleogel, diacylglycerol (DAG)-rich oil as a continuous oil phase, ethyl cellulose (EC) as a gelator and γ-oryzanol (GO) as an antioxidant were used. Effects of EC viscosity and EC/GO mass ratio on the physicochemical properties were studied. Besides, interactions between the components were analyzed by Fourier transform infrared spectroscopy and molecular dynamics (MD) simulation. The EC with a viscosity of 18–22 mPa s resulted in slightly higher oil binding capacity (99.84% vs 98.55% at 10% EC, and 99.92% vs 99.49% at 12% EC) and significantly stronger hardness and gel strength of DAG oil oleogels than EC with a viscosity of 45–55 mPa s. Moreover, the hardness and rheological properties of oleogels were negatively correlated to GO addition. MD simulation was used to understand this effect of GO addition, showing that EC-GO complex had lower binding energy (−107.14 kJ/mol) than the complexes of GO-DAG (−105.64 kJ/mol) and EC-DAG (−101.96 kJ/mol), leading to the disruption of the capacity of EC to structure DAG-rich oil. Interactions between the components were mainly governed by van der Waals interactions. The peroxide value of the oleogels decreased by 1.89 mmol/kg as EC18/GO mass ratio changed from 12:0 to 12:4, indicating good antioxidant activity of GO. Overall, the characteristics of DAG oil oleogels could be modulated by the addition of GO. The study may provide considerable potential to develop healthy and stable oleogels with high DAG, low saturated and trans-fatty acids for food industry.