The microstructure and gel properties of linseed oil and soy protein isolate based-oleogel constructed with highland barley β-glucan and its application in luncheon meat

Abstract

In this study, linseed oil-based oleogel was firstly constructed using soy protein isolate (SPI) and varying concentrations of highland barley β-glucan (HBG) by emulsion-templated approach. The microstructure and gel properties of linseed oil-based oleogel was evaluated for a deeper understanding of the interaction between HBG and SPI. Confocal laser scanning microscope showed oil droplets became smaller, more compact, and more uniformly distributed in the network as the concentration of HBG increased. FTIR analysis demonstrated the formation of a 3D network mainly via stretching intramolecular or intermolecular hydrogen bonding from SPI and HBG. SAXS pattern implied 7.608–8.128 nm Rg of oleogels. Frequency sweep measurements indicated higher concentrations of HBG caused more rigid microstructure network and greater mechanical strength of the solid-like system. Time sweep measurements showed the structure of oleogels could be recovered by 50–80% followed by the shear rate dropping from 10 s−1 to 0.1 s−1. Moreover, temperature sweep measurements showed no gel-to-sol phase transition happened from 5 °C to 100 °C. SPI/HBG mixed gels significantly increased the oil binding capacity by 8–22 times and slowed down the oxidation of linseed oil rich in n-3 polyunsaturated fatty acids. Linseed oil-based oleogel was then applied in luncheon meat as a healthy alternative to solid fats. Sensory evaluation presented the overall acceptance of luncheon meat decreased with the increasing oleogel substitution of pork backfat, but oleogel substitution of 25% pork backfat produced the desirable overall acceptance.