Non conventional chestnut flour based products processing by extrusion-cooking

Chestnut (Castanea sativa) flour (CF) is a typical product of Italian mountain agriculture. Studie on CF functional properties in relation to extrusion-cooking processes were conducted and CF resulted suitable for the extrusion-cooking process only if properly mixed with other flours. This is due both to its high sugar content, which has a restrictive effect on product gelatinization and limits product expansion, and to its high reducing sugar content, which could enhance the Maillard reaction rate at high extrusion temperature. The Maillard reactioncaused the occourrence of browning phenomena and flavour devolpment that could be desirable or undesirable depending on their extent. By the combination of extrusion and post extrusion process variables it was possible to produce CF based snack-like products and ready-to-eat breakfast cereals using a two step extrusion-cooking and toasting process. These products showed functional and physical properties similar to those of commercial products and acceptable sensory characteristics.