Thermal processing is the most common and traditional technique used for food processing. An adverse effect on organoleptic properties of foods caused by thermal processing has been reported. Therefore, milder processing techniques including novel thermal, minimal thermal and non-thermal processing has become the new trend. These techniques are claimed to provide food of high quality and with improved functionality. This chapter aims to provide a critical review of the effects of these milder processing techniques on the functional components of processed food. Recent developments in food processing operations involve technologies that avoid deleterious effects of heat on organoleptic properties and nutrients of foods. Alternative or novel minimal-thermal and non-thermal processing methods include: ultrasound, high hydrostatic pressure, radiation and pulsed electric field processing are being examined to produce safe and better quality food products. They may replace conventional thermal processes in certain applications and are particularly beneficial for thermally sensitive products.