Effect of Sucrose Replacement with Dietary Sweetener Stevioside and Adding Tragacanth Gum on Rheological and Micro- Structural Properties of Ghotab-Traditional Confectionary

The aim of this research was to investigate the possibility of using stevioside and tragacanth gum in replacing of sugar (sucrose) in Ghotab as an Iranian traditional candy. This research was carried out in order to find out the effect of replacing the sucrose by the ratio of 1 part of stevioside instead of 200 parts for sucrose according to the rate of sweetness of stevioside in compare with sucrose and addition of tragacanth gum at three levels (0.5, 1 and 5%) total (formula) on sensory and organoleptic qualities such as hardness, microstructure and color, using entirely random plan and average comparison by LSD. The results showed that a significant increasing and decreasing hardness by replacing of sucrose and addition of tragacanth, respectively (p≤0.05). In this respect, no significant differences was found between the reference samples and treatment containing 1% tragacanth and stevioside. No aftertaste was detected in the samples containing stevioside-tragacanth by the panelists, but more delicate samples were observed by addition of tragacanth up to 5%. structure of the texture revealed that by increasing of tragacanth content, the diameter, area of the air bubbles and prosity in Ghotab structure was significantly increased. However, the highest roundness and number of air bubbles were observed as well as, total in control samples. Color analysis of the samples showed that increasing of tragacant addition caused more color changes and browning index, in compare with the refrence. On the whole, it could be concluded that using of stevia-tragacanth in replacing of sucrose, could be a suitable was in order to produce a lower calories-Ghotabe.