Effect of tragacanth gum on texture and staling of commercial sponge cake

Tragacanth is a natural gum obtained from the dried sap of several species of Middle Eastern egumes of the genus Astragalus, that is a viscous, odorless, tasteless, water-soluble mixture of polysaccharides. Tragacanth is used in pharmaceutical and foods industries as an emulsifier, thickener, stabilizer, and texturant additive. Sponge cake is one of the most popular bakery products due to its nutritional value, ready-to-eat nature, long-shelf life and specifically its fine structure. Tragacanth gum can improve textural properties of bakery products duo to its nature as a hydrocolloid. In this study, texture profile analysis (TPA) and also cutting tests (for crumb and crust) were applied to find out the effects of tragacanth gum on the textural properties of commercial sponge cakes during 30 days. The concentrations of tragacanth gum were 0.1, 0.2, 0.3, 0.4, 0.6, and 0.8% (w/w) in the cakes’ batter. Results revealed that tragacanth gum up to 0.4% led to softening the texture of the cake and reducing the signs of aging. Application of tragacanth gum (up to indicated level) in bakery products, particularly the sponge cake, can improve textural properties and increase shelf life of these products.