Extraction and Functional Properties of Proteins from Pre-roasted and Enzyme Treated Poppyseed (Papaver somniferum L.) Press Cakes

Abstract

In this study, proteins of the defatted meals obtained from cold-pressed poppyseed previously treated (pre-roasting and enzyme against control) were extracted and their compositional and functional properties were determined. Saline-alkaline extraction (pH 11-12, and 0.2-0.6 M NaCI) and isoelectric point (pH 4.0-5.5) precipitation technique showed that seed pre-roasting enhances protein yield while enzyme treatment reduces it. There were 7 bands on SDS-PAGE, and enzyme treated samples were weaker than control. While enzyme treatment decreased denaturation temperatures (T_d), roasting enhanced the enthalpy change (ΔH) values. Pre-treatments caused a decrease in protein least gelling concentration (LGC) values. Water and oil holding capacities (WHC and OHC) were found lower in enzyme treated and higher in preroasted samples. Similar effects were also determined for emulsifying activity (EA) and emulsion stability (ES) values. While foaming capacity (FC) in treated samples decreased, foam stability (FS) increased oppositely. In conclusion, poppyseed meals can be nutritionally good source for diet protein, and a limited pre-roasting can be very beneficial for enhanced protein extraction yield and desirable functional properties.