A process for the production of a whole grain cereal meal, which comprises the steps of: a) grinding cereal caryopses into particles of diameter of not less than 2 mm; b) providing a wet heat treatment reactor comprising a cylindrical tubular body with horizontal axis, having at least one inlet opening (5, 6, 10) for the introduction of the ground caryopses of step a) and water or an aqueous solution and at least one discharge opening, a heating jacket for raising the temperature of said tubular body to a temperature of at least 80°C, and a rotor, arranged inside the cylindrical tubular body and comprising a shaft provided with elements projecting radially therefrom; c) feeding a continuous flow of said ground caryopses into said reactor, wherein the rotor is set in rotation at a speed greater than or equal to 150 rpm; d) feeding into said reactor, together with said flow of ground caryopses, a continuous flow of water or aqueous solution, which is dispersed into minute droplets; e) centrifuging said flows against the inner wall of the reactor, thus forming a highly turbulent, dynamic, thin, tubular fluid layer, in which the particles of ground caryopses and the droplets of water or aqueous solution are kept mechanically in intimate contact by the radially projecting elements of said rotor, while advancing in substantial contact with said inner wall of the reactor towards the discharge opening; f) discharging from the discharge opening a continuous flow of wet ground caryopses particles (moisture content 20-30%); g) providing a thermal dehydration and treatment reactor, comprising a cylindrical tubular body with horizontal axis, having at least one inlet opening and at least one discharge opening, a heating jacket for raising the temperature of said tubular body to a predetermined temperature, and a rotor arranged inside the cylindrical tubular body and comprising a shaft provided with elements projecting radially from said shaft; h) feeding said wet ground caryopses into said reactor through the at least one inlet opening, the inner wall of the reactor being kept at a temperature of at least 100°C by means of said heating jacket and the rotor being rotated at a speed of at least 150 rpm; i) centrifuging and causing said wet ground caryopses to advance inside the reactor by means of the action of said rotor; 1) discharging from the discharge opening of the reactor a continuous flow of ground caryopses with a moisture content of between 2% and 15%; m) subjecting said ground caryopses to a further grinding step, to reduce the particle size to a value less than or equal to 0.5 mm, thus obtaining said whole grain meal. a) grinding cereal caryopses into particles of diameter of not less than 2 mm; b) providing a wet heat treatment reactor comprising a cylindrical tubular body with horizontal axis, having at least one inlet opening (5, 6, 10) for the introduction of the ground caryopses of step a) and water or an aqueous solution and at least one discharge opening, a heating jacket for raising the temperature of said tubular body to a temperature of at least 80°C, and a rotor, arranged inside the cylindrical tubular body and comprising a shaft provided with elements projecting radially therefrom; c) feeding a continuous flow of said ground caryopses into said reactor, wherein the rotor is set in rotation at a speed greater than or equal to 150 rpm; d) feeding into said reactor, together with said flow of ground caryopses, a continuous flow of water or aqueous solution, which is dispersed into minute droplets; e) centrifuging said flows against the inner wall of the reactor, thus forming a highly turbulent, dynamic, thin, tubular fluid layer, in which the particles of ground caryopses and the droplets of water or aqueous solution are kept mechanically in intimate contact by the radially projecting elements of said rotor, while advancing in substantial contact with said inner wall of the reactor towards the discharge opening; f) discharging from the discharge opening a continuous flow of wet ground caryopses particles (moisture content 20-30%); g) providing a thermal dehydration and treatment reactor, comprising a cylindrical tubular body with horizontal axis, having at least one inlet opening and at least one discharge opening, a heating jacket for raising the temperature of said tubular body to a predetermined temperature, and a rotor arranged inside the cylindrical tubular body and comprising a shaft provided with elements projecting radially from said shaft; h) feeding said wet ground caryopses into said reactor through the at least one inlet opening, the inner wall of the reactor being kept at a temperature of at least 100°C by means of said heating jacket and the rotor being rotated at a speed of at least 150 rpm; i) centrifuging and causing said wet ground caryopses to advance inside the reactor by means of the action of said rotor; 1) discharging from the discharge opening of the reactor a continuous flow of ground caryopses with a moisture content of between 2% and 15%; m) subjecting said ground caryopses to a further grinding step, to reduce the particle size to a value less than or equal to 0.5 mm, thus obtaining said whole grain meal.