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Background and Objectives: The quality of cakes made of wheat flour depends on the quantity and quality of its gluten proteins however, these proteins may have side effects for some people, including the patients with celiac, and the only way to cure this disease is to take a lifelong gluten-free diet. Materials and Methods: This research aims to produce gluten- free cake by using rice flour and xanthan and tragacanth gums, including two treatments of xanthan gum (0.5 &1 %), two treatments of tragacanth gum (0.5 & 1%), four combination treatments of xanthan gum and tragacanth, and one control treatment (without gum). The effects of tragacanth and xanthan gums on the texture characteristics, moisture content, water activity (aw), color, volume, apparent density, and porosity of the resulting cake were investigated. The data obtained were analyzed by the use of factorial experiments with three replications (3*3) and a Completely Randomized Design (CRD). Results: The results showed that the treatments containing gum have less texture stiffness compared to the control. Among the treatments, those having the combination of 0.5% tragacanth and 1% xanthan gum hold the maximum content of moisture. The L component amount of gluten-free cake samples was increased compared to the control while the rate of a and b components was decreased. The maximum amount of aw is related to the 0.5% treatment tragacanth and 1% xanthan, and the lowest aw belongs to the control. Apparent and bulk density has a difference with the control, and the minimum amount and the maximum amount belong to the treatment containing 1% tragacanth and the control, respectively. Conclusions: Samples containing 1% xanthan and 0.5% tragacanth could be desirable due to less texture stiffness, maximum content of moisture and aw, high color score, minimum density, and better keeping quality during the storage period. Keywords: Gluten-free cake, Tragacanth, Xanthan, Cake texture, Celiac

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Background and Objectives: Increased frozen food consumptions have led to increased demands for gums with unique properties. Gums are used for the stabilization of food products that undergo various processing. Due to increases in gum use in food industries and high prices of commercial gums, use of native gums has been considered important recently. Therefore, the aim of this study was to assess effects of freezing treatments on textural characteristics of Lepidium perfoliatum seed and xanthan gums at various concentrations.
Materials and Methods: Effects of freezing process at -18 ºC for 24 h were investigated on textural characteristics of Lepidium perfoliatum seed gum at various concentrations of 0.50, 1.00, 1.50 and 2.00% )w/w) and results were compared with those a commercial xanthan gum.
Results: Results showed that hardness, stickiness, consistency and adhesiveness increased significantly by increasing the concentration of gums from 0.50 to 2% (p > 0.05). Values of the textural parameters were higher in xanthan gum than Lepidium perfoliatum seed gum. Freezing process at low concentrations of gums led to significant increases in textural parameters (p < 0.05). However, textural parameters of gums at higher concentrations decreased after freezing treatments. Xanthan gum included a greater L* value than that Lepidium perfoliatum seed gum did. Therefore, appearance of xanthan gum was brighter than appearance of Lepidium perfoliatum seed gum. Furthermore, freezing process did not include significant effects on a* and b* values of gums.
Conclusions: Due to the high similarity of Lepidium perfoliatum seed gum with xanthan gum in terms of stability (high stability), the former gum can be considered as an appropriate stabilizing agent under freezing conditions. These findings suggest that Lepidium perfoliatum seed gum, as a stabilizer, can be used in formulation of frozen foods to provide specific functionality, minimize negative effects of freezing and decrease production costs.