Abstract: A yeast extract is produced by preparing a suspension containing yeast, applying an electric field treatment to the suspension, and then autolyzing the suspension. In this electric field treatment, a voltage to be applied is less than 1000 V/mm, and a temperature of the suspension during an application period of the voltage is 64° C. or less. According to such a production process, a content of amino acids in the yeast extract can be improved. Among amino acids, branched chain amino acids or the like can be efficiently increased.

Abstract: Disclosed is an electric heating device for heating a fluid food material, for example, a liquid food material with high viscosity such as mayonnaise or the like, and a solid-liquid mixed food material such as a mixture of tea powder, coffee powder or the like and water, in which a solid and a liquid are mixed. The heating device includes a cylindrical container body having the bottom end thereof and containing the fluid food material. A cylindrical outer electrode is mounted in this container body, and an inner electrode, having an outer circumferential surface opposite to the inner circumferential surface of the outer electrode, is arranged at the center of the container body. An electric power is supplied from a power supply to the inner electrode and the outer electrode, and an electric current flows through the food material injected in the container body, whereby the food material is heated by the Joule heat.

Abstract: There is disclosed a heating system for producing food stuffs such as a paste food stuff having minced flesh of fish meat as a raw material. The heating system comprises: an electrode row or rows, in which a plurality of roller electrodes are disposed in parallel to one another; and a water permeable film or films trained across the roller electrodes making up the electrode row or rows. The food stuffs are conveyed by the movement of the water permeable film or films and electrical power is supplied to the roller electrodes in such way that electric current flows between pairs of the roller electrodes along current paths extending through the water permeable film or films and the food stuffs to make the food stuffs generate Joule heat. With this arrangement, the food stuffs are quickly heated. The food stuffs are also guided by the water permeable film or films.