Animal fat replacement with plant-based emulsion gels in hybrid meat products and understanding their properties using synchrotron light

Abstract: The overall objective of this study was to utilize pulse proteins to stabilize canola oil-in-water emulsions as an animal fat replacer in hybrid bologna with desired quality and sensory attributes. Oil-in-water emulsions were prepared by homogenizing 40wt% canola oil in 10wt% faba bean protein concentrate (FPC) dispersion. The emulsions were heated (90ºC for 30 min) prior to inclusion in the bologna to induce gelation. The hybrid bolognas were made by completely replacing the pork back-fat with the emulsion gels. As a control, full-fat bologna (20% animal fat) and low-fat bologna with an equivalent amount of fat as in the hybrid bologna were also prepared. The mixtures were stuffed into waterproof casings and heat-treated to an internal temperature of 72 oC for 5 min. The results showed that replacing pork back-fat with heated or un-heated FPC emulsions significantly improved the bologna characteristics compared to the low-fat control bologna. The hybrid bologna, having lower fat content than full-fat bologna, showed desirable texture, color and water-holding capacity. All bologna samples had an acceptable appearance, and no structural failure or emulsion separation was observed. All bologna samples showed similar properties in terms of cooking loss, purge loss, expressible moisture and elasticity, indicating that pork back-fat replacement with heat-treated emulsion had no adverse effect on the bologna characteristics. The synchrotron-based infra-red (IR) mapping and micro-computed tomography showed spatial distributions of fats and proteins from animal and plant origin, which significantly influenced the microstructure of the meat samples. Conclusively, FPC-stabilized emulsions with appropriate protein and oil concentration could be converted into a strong self-supporting gel by heat treatment and used to replace pork back-fat in bologna without any adverse effect.