## 3 Results and Discussion
### Physicochemical Properties
#### 3.2.5 Gelatinitisation  
Gelatinisation is identified as a phase transition of starch granules from an ordered to disordered state or known as changes from crystalline to the amorphous structure of starch granules [73]. Gelatinisation occurs in the range from 60 \({}^{\circ}\)C to 80 \({}^{\circ}\)C with the presence of water during thermal treatment. Figure 2 presents the gelatinisation curve for rice flour samples. The gelatinisation onset temperature (T\({}_{\rm o}\)) ranges between 71.43 \({}^{\circ}\)C and 77.41 \({}^{\circ}\)C. The highest value of T\({}_{\rm o}\) was presented by TQR rice flour, at 77.41 \({}^{\circ}\)C, and the lowest was from Bario Adan Halus (71.43 \({}^{\circ}\)C). Moreover, the T\({}_{\rm p}\) and T\({}_{\rm f}\) ranged between 77.03 \({}^{\circ}\)C and 80.49 \({}^{\circ}\)C, and between 80.77 \({}^{\circ}\)C and 84.45 \({}^{\circ}\)C, respectively. The highest T\({}_{\rm p}\) and T\({}_{\rm f}\) were shown by TQR rice flour, at 80.49 \({}^{\circ}\)C and 83.22 \({}^{\circ}\)C, respectively, whereas Bario Adan Halus showed the lowest, at 77.03 \({}^{\circ}\)C and 80.77 \({}^{\circ}\)C, for T\({}_{\rm p}\) and T\({}_{\rm f}\), respectively. Nevertheless, the \(\Delta\)H\({}_{\rm gel}\) of rice flour samples varies between 0.79 J/g and 2.59 J/g. \(\Delta\)H\({}_{\rm gel}\) denotes the thermal energy required to convert the initial crystalline state to an amorphous structure within the starch granules [74]. A high \(\Delta\)H\({}_{\rm gel}\) implies high energy required to transform the starch structure from the ordered (crystal) to disordered (amorphous) forms, whereas a low \(\Delta\)H\({}_{\rm gel}\) implies the opposite. The \(\Delta\)H\({}_{\rm gel}\) of Bario rice flour varied widely, with the highest value found in Bario _Celum_ rice flour (2.59 J/g) and the lowest value found in TQR rice flour (0.79 J/g). The variation in \(\Delta\)H\({}_{\rm gel}\) can be roughly determined by looking at the area under the DSC curve of gelatinised rice flour in Figure 2.  
According to the results, the gelatinisation of TQR rice flour generally requires a higher temperature but less energy to initiate the breakdown of hydrogen bonds in a double-helical amylopectin chain. A previous study by [PERSON] et al. [75] reported that the lower \(\Delta\)H\({}_{\rm gel}\) is due to the formation of cracks on the starch surface due to the higher gelatinisation temperature, which facilitate water penetration into the starch granules and further penetration into the starch's crystalline areas, consequently reducing the energy required for gelatinisation. On the other hand, the gelatinisation temperature of Bario Adan Halus was the lowest of all (T\({}_{\rm o}\) = 71.43 \({}^{\circ}\)C, T\({}_{\rm p}\) = 77.03 \({}^{\circ}\)C, and T\({}_{\rm f}\) = 80.77 \({}^{\circ}\)C) but considerably high in \(\Delta\)H\({}_{\rm gel}\) (2.13 J/g). A previous study by [PERSON] et al. [76] also obtained a similar gelatinisation pattern for rice flours. [PERSON] et al. [77] explained that a lower gelatinisation temperature contributes to the upsurge in \(\Delta\)H\({}_{\rm gel}\), and \(\Delta\)H\({}_{\rm gel}\) has an inverse proportional relationship with amylose content, in which \(\Delta\)H\({}_{\rm gel}\) increases when amylose concentration decreases. Similarly, the amylose contents of Bario Adan Halus (26.67%) and Bario Celum (26.68%) were the lowest possible among all, thus resulting in the highest \(\Delta\)H\({}_{\rm gel}\), 2.13 J/g and 2.59 J/g, respectively. According to [PERSON] and [PERSON] [64], choosing high \(\Delta\)H\({}_{\rm gel}\) flours with low T\({}_{\rm p}\) is preferable, especially to improve crumb cohesiveness and resilience. Moreover, a positive correlation exists between T\({}_{f}\) and the specific volume of the end product. This outcome might be linked to the rising of bread during baking [64]. Bario _Tuan_ and Bario _Merah Sederhana_ exhibited greater T\({}_{f}\) than the control sample, which might have delivered a positive impact on the final product in terms of the specific volume.