Thixotropy

Students feel the rheological differences between different starch types with Prof. Dr. Sibel Ozilgen as a part of 'Culinary Science Laboratory' course at the Gastronomy and Culinary Arts Department, Yeditepe University. Starch is a polysaccharide (long chains of glucose units), which is a major component of many plants. Seeds, cereals, roots, and the tubers are the main sources of starch. The most common starches in culinary processes are corn (maize), rice, wheat, potato, and tapioca (cassava). Thickening, body and texture formation, binding, coating, and moisture retention are the primary functions of starches in cooking processes. Chemical structure of the starch and the size of the starch granule determine the viscosity of the starch gel, its thixotropic (shear thickening) properties, the rate of gelatinization, the strength of the gel, and the gelatinization temperature. Each starch type has its own chemical structure and they are not interchangeable. Using the correct type of starch is important in culinary processes.