Effect of shortening type on the rheological characteristics of cookie dough

The effect of four types of shortening including a commercially vegetable oil (as control), palm olein (PO), palm stearin (PS), and a blend of the latter two oils with rapeseed oil (BF) on the rheological properties of cookie dough was determined by using dynamic oscillatory measurement testing. All of the obtained dough treatments showed weak liquid viscoelastic behavior. Their storage (G ) and loss (G ) moduli were almost the same with a loss tangent (tan ?) value of about 1. G was greater than G in most of the measured frequency range. Both G and G were frequency dependent and decreased with increasing of frequency. Differing oil compositions were found to differently affect on the overall strength of the doughs. The control dough showed the lowest frequency dependence. At lower frequencies, PO dough had the same consistency as the control, but at higher frequencies, its interaction was reduced leading to a weaker system. PS and BF doughs had stronger systems with higher values of G and G at low frequencies; both showed a dramatic drop in the values of G and G at about 1 Hz. After this frequency, they showed similar rheological profile to the control. Baking test showed that the final quality of the baked products was significantly different in both appearance and internal texture.