Optimization and evaluation of physicochemical and sensory properties of extruded alpha-linolenic butters using by RSM and PCA methods

In this paper, in order to optimize the rheological properties of extruded alpha-linolenic butters, the effect of extrusion conditions, including extruder shear rate (500, 750, 1125, 1500 and 1750 S-1), feed temperature (5, 7, 10, 13 and 15°C) and storage temperature (5, 7, 10, 13 and 15°C) on the physicochemical and sensory properties of extruded alpha-linolenic butter were examined after 15 days storage, then the relationships between physicochemical and sensory properties of extruded alphalinolenic butters were evaluated using by principal component analysis (PCA) method. About the mechanical treatment, increasing extruder shear rate resulted in extruded and refrigerated samples with lower hardness, higher adhesiveness and L٭value. Higher storage temperature increased the acid value, but reduced the hardness. Feed temperature had no significant (p > 0. 05) effect on the physicochemical and sensory properties of the extruded and refrigerated samples. The overall dispersal of variables in the principal components showed that the acid value, adhesiveness and firmness (instrumental measurement) were mainly related to the same sensory measurements. In addition, the close relationship between acid flavour and total acceptance of the samples showed that the acid flavor is more important factor for total acceptance of butter compared to the other parameters.