Replacement of beef fat with faba bean protein isolate-stabilized oil-in-water nanoemulsion gels in hybrid beef burger formulations

The overall objective of this study was to utilize faba bean protein isolate (FBI) to stabilize 30wt% canola oil-in-water nanoemulsions as an animal fat replacer in hybrid beef burgers to achieve the desired quality and sensory attributes. Nanoemulsions were prepared using a pilot-scale microfluidizer at 103.4 MPa for one cycle. Sodium chloride (2%) was added to the nanoemulsion, stuffed into waterproof casings, and heat-treated to an internal temperature of 90°C for 30 min. This resulted in a self-supporting gel used as a beef fat replacer in hybrid beef burgers. A total of six burger formulations were developed with different replacements of beef fat (0, 50, 100%) to achieve a 10% low-fat level. Conventional burgers with 20% (full-fat) and 10% (low-fat) fat were used as controls. Burgers were assessed for their quality attributes and consumer sensory evaluation. Replacing beef fat with nanoemulsion gel improved the protein content of the hybrid burgers. The cooking yield, juiciness, and water-holding capacity improved with the beef fat replacement. Hardness and chewiness increased, but no significant difference was observed in resilience, adhesiveness, cohesiveness, and springiness. Instrumental colour analysis showed that replacing beef fat with the nanoemulsion gel increased the lightness of the raw and cooked burgers, with no significant difference in the redness and internal colour of the cooked burgers. TBARS results showed that nanoemulsion gels reduced lipid oxidation in hybrid burgers over a storage period of two months. Sensory evaluation showed that all the formulated burgers were acceptable, with no significant differences in appearance, surface colour, and juiciness. Panellists indicated a high degree of liking for the overall acceptability of the hybrid beef burgers with the desire to have more. In conclusion, acceptable hybrid beef burgers with improved nutritional properties can be developed by replacing beef fat with FBI-stabilized canola oil-in-water nanoemulsion gels.