## 3 Main Findings
### Ingredients and Their Effects on Gluten-Free Dough Rheology and Bread Quality
#### 3.3.4 Improvers for Gluten-Free Doughs and Baked Products  
Hydrocolloids have been widely investigated as additives and improvers [14]. The most noteworthy applications are: to improve food texture and viscoelasticity [13; 14; 15; 17]; act as water binders [13; 14; 15; 17]; extend the overall quality of products during storage [14]; slow down starch retrogradation [14]; and act as a gluten substitute [13; 14]. Usually, they are added to dough as a structuring agent, with the aim of imitating gluten network properties [13; 14; 17]. Their high water retention capacity, among other characteristics, means that they are able to give stability to productsthat undergo successive freeze-thaw cycles. Moreover, they are a good fat substitute in many products, especially as, at concentrations below 1%, they have been found to have a significant influence on dough rheology and bread characteristics [14; 15]. The review highlighted that carboxymethyl cellulose (CMC), guar gum, sodium alginate, \(\kappa\)-carrageenan, xanthan gum, and hydroxypropyl methylcellulose (HPMC) are effective improvers [13; 14; 15; 3; 17]. These agents are extensively used to modify starch gelatinization, and improve pasting properties and gelling. Moreover, they have been found to improve dough development and gas retention capacity, through an increase in viscosity, with a subsequent increase in loaf volume [13; 14; 15; 17]. In particular, [PERSON] et al. (2008) [14] highlighted that hydrocolloid addition can increase elasticity and deformation resistance. The literature reports a high degree of variation in functionality. The type and extent of the improvement depends on the origin and chemical structure of the hydrocolloid, and its concentration. Cellulose derivatives are obtained by chemical modification, which ensures uniformity. These agents have high water holding capacity (due to their hydrophilic groups), and other desirable properties, such as interfacial activity within the system during proofing, and the formation of gel networks during breadmaking [14]. They have been found to increase viscosity and gas retention capacity, with a consequent increase in loaf volume [14; 15]. Moreover, the hydrophobic-hydrophilic balance in HPMC has been reported to strengthen crumb grain and increase moisture content [14]. CMC interacts preferentially with protein, and HPMC with starch [14]. The latter study reported that CMC and pectin significantly increased loaf volume, porosity, and elasticity. Xanthan and pectin increased cooking stability, while \(\kappa\)-carrageenan mainly affected the formation of the amylase-lipid complex. In conclusion, the effects of the most widely used hydrocolloids depends on their source, chemical structure, extraction process, chemical modification, and dosage. Moreover, the most suitable hydrocolloid, and the optimal dosage, are a function of the selected base flour, and the desired characteristics of the final product. Similarly, emulsifiers appear to be a promising way to stabilize and structure gluten-free dough. In particular, [PERSON] and [PERSON] (2015) [13] highlighted that they are able to stabilize gas bubbles during proofing and, consequently, improve crumb texture. With respect to dough rheology, the latter study highlighted that the addition of xanthan gum resulted in the highest increase in viscoelastic moduli, and lowest hardness in bread. Diacetyl tartaric acid ester of mono- and diglycerides (DATEM), is another emulsifier that has been found to increase viscoelastic moduli and loaf specific volume, and decrease crumb firmness [13; 14; 15; 17]. This is due to the ability of emulsifiers to improve dough consistency and pasting properties. On the other hand, [PERSON] and [PERSON] (2015) [13] highlighted that the addition of inulin decreased dough viscoelasticity. This decrease was higher for inulin with shorter chains, due to inulin-inulin interactions. Last but not least, enzymes have been found to improve both doughs and products.