Gum tragacanth oil/gels as an alternative to shortening in cookies: Rheological, chemical and textural properties

In recent years the replacement of fat content in food products by vegetable oils in gel form, has been an emerging technology. In this study, gum tragacanth, as oil structuring agent with a concentration of 1.5, 1.7, 1.9 and 2.1 g/100 g, together with sesame oil as the oil phase, were utilized to prepare oil/gels as a fat replacer in cookie dough. The oil/gels demonstrated shear-thinning behavior. Based on the results, the oil/gels containing 1.5 and 2.1 g/100 g of gum were selected as shortening replacers at levels of 25, 50, 75 and 100 g/100 g in the dough formulation. Lower replacement levels (25 and 50 g/100 g) of oil/gels, led to higher elastic and loss moduli in comparison to shortening; whereas higher oil/gels content resulted in lower values. Replacement of shortening by oil/gels reduced the fat content by 27 and 30%. Cookies containing oil/gels produced sensory scores close to those of the shortening sample. Cookie samples with oil/gels containing 1.5 g/100 g of the gum retained a softer texture during storage. Overall results revealed that replacement of up to 50 g/100 g of shortening with oil/gels containing 1.5 g/100 g of the gum tragacanth could be a possible alternative for the development of healthier products.