## 3 Results and Discussions
### Pasting Properties of Naturally fermented cassava Root flour Using Different Fermentation Times  
All the parameters of the pasting properties underwent a uniform decline with the increase in fermentation time for cassava root flour from 0 h (control) to 48 h, as depicted in Table 3. As pointed out previously, peak viscosity, which is the lowest value of rapid Visco units (RVU) recorded for 48 h of fermentation, decreased significantly from 420.3 \(\pm\) 4.2 RVU (control) to 329.5 \(\pm\) 3.7 RVU. The increase in viscosity peak significantly diminished commensurate with time, culminating in a 21.6% decrease when compared to the control sample, which is suggestive of starch granule or sequential amylose chain degradation, likely due to enzymatic, i.e., amylolytic activity, during fermentation. This has been extensively documented in the literature as a characteristic of fermentation, particularly in the case of cereals or tuber starches [39; 40].  
The trough, which is the lowest point of viscosity reflecting the minimum viscosity after peak value during constant heating [41], showed a similar declining trend (from 281.5 \(\pm\) 3.7 RVU at 0 h to 239.3 \(\pm\) 3.1 RVU at 48 h). Breakdown, calculated as the difference between peak viscosity and trough, reflects the stability of swollen granules when exposed to shear and heat.  
Breakdown reduced from 138.8 \(\pm\) 2.8 RVU (control) to 90.2 \(\pm\) 1.9 RVU (48 h), a 35% decrease. This indicates greater resistance to disintegration induced by shear, most likely due to partial hydrolysis of starch molecules resulting in smaller, more stable granules.  
Final viscosity, which is the viscosity after cooling and indicates the extent of gel formation, was also reduced from 372.2 \(\pm\) 3.1 RVU (control) to 318.4 \(\pm\) 3.2 RVU (48 h). The setback, the difference between the final viscosity and trough, indicates retrogradation and amylose re-association of the sample. Setback decreased from 90.7 \(\pm\) 2.2 RVU to 79.1 \(\pm\) 2.1 RVU, indicating that retrogradation was lower in the fermented samples. This is likely due to the reduction in amylose chains during fermentation, where they were converted to shorter disassociating dextrin, which limits molecular re-association upon cooling [42].  
The change in pasting temperature (the temperature at which viscosity begins to increase) ranges from 72.1 \(\pm\) 0.3 \({}^{\circ}\)C (control) to 69.8 \(\pm\) 0.3 \({}^{\circ}\)C (48 h). This change indicates that the energy necessary for starch gelatinization is likely lower during fermentation due to a partial hydrolysis of starches, which facilitates water absorption. Peak time, or time to reach peak viscosity, also reduced slightly from 4.3 \(\pm\) 0.1 min to 4.0 \(\pm\) 0.1 min, indicating faster gelatinization in fermented samples.  
These changes are likely due to the hydrolytic impact of fermentation with microbial or auto-fermentative enzymes, like \(\alpha\)-amylases and glucoamyloglucosidases that polymerize old starch polysaccharides into smaller pieces and oligosaccharides [42]. Fermentation increases the starch gelatinization temperature and enthalpy and reduces the setback viscosity of food samples. This is due to an increase in the relative crystallinity of starch and a decrease in the amorphous region of starch granules by microorganisms. On the other hand, improvement in retrogradation means better suitability for porridge or baked goods, especially when those foods need to have smooth textures and long shelf life. However, lower viscosity might be a problem for some applications requiring high gel strength, i.e., some noodle or dumpling recipes.