Ahmad Shakerardekani - Pistachio Research Center, Horticultural Sciences Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Rafsanjan, Iran
Roselina Karim - Faculty of Food Science & Technology, Universiti Putra Malaysia

Background: Pistachios is one of the popular tree nuts in Iran and other countries. The effect of pistachio kernel roastingand milling parameters on the quality of pistachio paste was investigated in this study.Material and Methods: Roasting variables were roasting temperature (۹۰-۱۹۰°C) and roasting time (۵-۶۵ min). Fourgrinding gap sizes (۲۰, ۴۰, ۶۰, and ۸۰ µm) were used to prepare pistachio pastes.Results: Increasing roasting time and temperature had inverse associations with colour attributes of both kernels andpistachio powders, except for 'a' value of pistachio powder. The hardness (N) and colour parameters (yellowness index, Lvalue and b value) of pistachio kernels and the 'a' value of pistachio powder can be used to control the roasting quality ofpistachio kernels. The colloidal stability (CS) of pistachio pastes was found to be affected by particle size.Conclusion: The recommended roasting condition ranges of the kernels for the pistachio paste production were ۱۳۰-۱۴۰°C(۳۰-۴۰ min). The most stable pistachio paste was obtained when the gap size of the mill was ۲۰ µm.

Color, nut paste, pistachios, Response Surface Methodology