Experimental and theoretical analyses of hazelnut roasting process in fluidized bed dryer

The main objective of the thesis was experimental analyses and mathematical modeling of drying of hazelnut during roasting in fluidized bed reactor. Roasting of hazelnut is a temperature depentent process and involves a number of changes , as heat and mass transfer, chemical reactions and texture changes etc. This changes are important because they affect flavor, texture and aroma of the end product. The purpose of the hazelnut roasting is to promote flavor and texture and finally increase the overall palatabality of the hazelnut. Fluid bed roasting has been choosed for his study because it is expected the same roasting effect in fluidized bed dryer in shorter time and better overall palatability of the product than classical convective dryer. In this experiment for roasting have been used the tombul variety hazelnut of Giresun kind, harvested in Oedu in year of 2003. The samples as shelled have been dryed naturaly undar sunshine. Hazelnut samples have been left in the same basket for a month for arriving same moisture content. The goal of this study is to determine the drying charecteristics of the hazelnut during roasting and comparing with the other roasting systems due to data taken from experiments. It has been given the necessary fundamental information about the roasting mechanism and the drying too. In this study a new method for roasting of hazelnut has been tested. The roasting time in classical bant dryer is relative high. And after roasting in classical conveyor dryer, the samples of hazelnut have to be blanched. The blanching process takes a lot time and energy and mancraft. In fluidized bed dryer, the blanching occurs itself. A fluid bed dryer of small size have been built in the laboratory. The roasting and finally the drying of hazelnut have eben experimentally investigated. It is known the deficiency by the calculating of drying processes. Therefore it has been made some comparison between the experimental and modeling data. The modeling mentioned above ahve been builtdue tu finite difference method with implicit approaching