Thesis Type: Postgraduate
Institution Of The Thesis: Middle East Technical University, Faculty of Engineering, Department of Food Engineering, Turkey
Approval Date: 2014
Thesis Language: English
Student: BADE TONYALI
Principal Supervisor (For Co-Supervisor Theses): İlkay Şensoy
Co-Supervisor: Zümrüt Ögel
Abstract:As the health and food relationship became important, tomato pulp was added as a functional ingredient to the extrudates. Effects of extrusion on the functional properties of the extrudates and in vitro bioaccessibility of lycopene after extrusion were investigated. Two different temperature set was applied during extrusion: 80 °C, 90 °C, 100 °C and 130 °C (die: 116 °C) and 80 °C, 100 °C, 130 °C and 160 °C (die: 139 °C), screw speed and feed rate were kept constant, 225 rpm and 36 ± 1 g/min, respectively. Feed moisture content was adjusted to 30 ± 1 % with the addition of tomato pulp. Antioxidant activity and total phenolic content were found to decrease after the extrusion process. The extrudates which were obtained at 160°C last zone treatment temperature were found to have higher antioxidant activity and total phenolic content compared to samples with 130°C last zone treatment temperature. Data indicates a complete gelatinization during extrusion. High-performance liquid chromatography (HPLC) analysis indicated that lycopene content decreased after extrusion process when feed and extruded samples were compared. In vitro bioaccessibility of lycopene for the extruded samples with 160°C last zone temperature was higher than the feed and extruded samples with 130°C last zone treatment temperature.