Fig. 1: Schematic of the UFH process for meat preservation.

a Demonstration of the heating process. Carbon felt is used as the heating element, due to its high electrical resistance. The arrow marks the electric current direction. b Comparison of operating temperature and time of conventional food heating methods with the UFH method (error bar symbols represent value ranges in the reported data). c–e Schematic appearance of a beef cube before (c) and after heating treatment (d, e). After the UFH is applied to the entire surface of the meat, producing a pale appearance (d), while the interior meat remains fresh, as revealed in the cross-sectional view of (e). The thickness of the outer layer with respect to the bulk sample is not to scale.