Effects of carrot dietary fiber and sugarbeet fiber on the quality of tarhana

Tarhana is a widely consumed cereal-based fermented product in Turkey. Carrot is an important root vegetable and usually used for juice production. By-products (pomace, stells etc.) after juice extraction is generally discarded or used as animal feed. Carrot dietary fiber (CF) obtained from carrot pomace still contain high contents of beneficial substances. Sugarbeet fiber (SBF) is the major by-product of sugar industry. CF and SBF are both considered as attractive alternative sources of dietary fibers. The aim of this work was to evaluate how the incorporation of carrot fiber (CF) at different levels in tarhana formulation affects the quality of tarhana. During the production of tarhana, wheat flour of tarhana was first partially (4, 8, 12, 16 and 20%) substituted with CF. In the second part, CF was used to replace wheat flour at the same levels with 10% SBF, while the level of all other ingredients was maintained. Crude protein, ash and total dietary fiber (TDF) contents, pH, titratable acidity, CIE color values (L*, a*, b*),sensory properties of tarhanas were analyzed. TDF contents of CF and SBF were determined 61.7 and 69.8%, respectively. While addition of both CF and CF-SBF increased ash contents, pH and titratable acidity values of tarhanas, the protein contents decreased significantly (p<0.01). TDF contents of both CF and CF-SBF supplemented tarhanas increased significantly with increasing addition levels (p<0.01). Although the lightness (L*) of the tarhanas supplemented with fibers increased significantly (p<0.01), tarhanas with CF had the highest increase in L* values. Tarhanas supplemented with CF generally gave higher a* and b* color values as compared to CF-SBF supplemented ones at all levels. As the CF addition level increased, overall sensory scores of the tarhanas decreased significantly (p<0.01). On the contrary, overall sensory scores of tarhanas supplemented with CF-SBF generally increased significantly (p<0.01). Addition of both CF and CF-SBF into the tarhana formulations were evaluated as acceptable in terms of most of the sensory properties upto 8 and 12%, respectively.