Original scientific paper
QUALITATIVE AND ENERGETIC CHANGES OF HAZELNUTS AFTER THE PROCESS OF CONVECTIVE DRYING
Ana Matin
; Agronomski fakultet Sveučilišta u Zagrebu, Svetošimunska cesta 25, Zagreb, Hrvatska
Tajana Krička
; Agronomski fakultet Sveučilišta u Zagrebu, Svetošimunska cesta 25, Zagreb, Hrvatska
Vanja Jurišić
; Agronomski fakultet Sveučilišta u Zagrebu, Svetošimunska cesta 25, Zagreb, Hrvatska
Nikola Bilandžija
; Agronomski fakultet Sveučilišta u Zagrebu, Svetošimunska cesta 25, Zagreb, Hrvatska
Ivan Kuže
; Agronomski fakultet Sveučilišta u Zagrebu, Svetošimunska cesta 25, Zagreb, Hrvatska
Neven Voća
; Agronomski fakultet Sveučilišta u Zagrebu, Svetošimunska cesta 25, Zagreb, Hrvatska
Abstract
Due to increased moisture level after harvesting, hazelnut has to be thermally treated in order to reach the equilibrium moisture, a form in which hazelnut is marketed throughout the year. Convection drying is used as one of the thermal finishing procedures. The aim of this study was to determine how the convection drying process influences the qualitative properties of nut, as well as the fuel properties of
nutshell. In this investigation, two hazelnut cultivars, Istria Long-shaped and Tonda Romana were used. Hazelnut fruits were convection dried at the temperature of 50°C and air velocity of 1.0 m s-1. Based on the results obtained, water release rate from hazelnut fruits was determined, as well as changes of physical (dimensions, sphericity, density and volume), chemical (water, ash, protein, fat and carbohidrates content) and fuel (water, ash, coke, fixed carbon, nitrogen (N), carbon (C), sulphur (S), hydrogen (H), oxygen (O), volatile compounds and combustible content, higher Hg and lower Hd heating values) properties of hazelnuts. The majority of nutritive
properties were preserved in the fruit, whereas it was found that hazelnut shell had good fuel properties after thermal finishing.
Keywords
hazelnut; convection drying; energy
Hrčak ID:
109806
URI
Publication date:
14.10.2013.
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