## 3 Results and Discussions
### Phenolic Profile of Cassava Root Flour Naturally Fermented Using Different Times (mg/g)
Yeasts and lactic acid bacteria (LAB), involved in fermentation, are known to hydrolyze phenolic compounds through the action of feruloyl esterases, \(\beta\)-glucosidase, decarboxylases, and other glycosidic enzymes, yielding free forms [34]. For instance, the release of ferulic acid is generally associated with LAB-mediated cleavage of arabinylan-phenolic complexes, together with hydrolysis of the arabinoxylan backbone [44]. Furthermore, it is possible that some phenolic derivatives are synthesized via microbial metabolism, such as gallic acid resulting from the hydrolysis of decarboxylated hydroxycinamic acids like caffeic acid to dihydrocaffeic acid [45]. The increased bioavailability of phenolics and the resulting antioxidant activities of the functional compounds present in fermented products are significant from a nutritional perspective. The presence of phenolic compounds, which are known as strong antioxidants, can increase the health benefits of the product, acting as an anti-inflammatory and anti-carcinogenic agent. For example, gallic and caffeic acids are noted to exhibit high radical-scavenging activity [46], and ferulic acid enhances gut health by promoting microbial balance in the gut [47]. These phenolic compounds with \"chain-breaking antioxidant\" properties work by giving a hydrogen atom from their hydroxyl group to a free radical, particularly peroxyl radicals [48]. Higher phenolic content can also be beneficial from a food processing standpoint because it may decrease the oxidative reactivity and improve the shelf life of a product [49]. These results indicate that a 48 h fermentation period seems to increase the release of phenolic content, which can be used to optimize industrial fermentation protocols. However, further extending fermentation time may impact other measures of quality, such as texture or flavor, as noted in a study regarding the fermentation and the pasting properties of starch, where viscosity was inversely proportional to fermentation time [17]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Phenolic Compound** & **0 h (Control)** & **12 h** & **24 h** & **48 h** \\ \hline Gallic acid & 1.32 \({}^{\text{a}}\)\(\pm\) 0.1 & 1.68 \({}^{\text{b}}\)\(\pm\) 0.1 & 2.15 \({}^{\text{c}}\)\(\pm\) 0.2 & 2.74 \({}^{\text{d}}\)\(\pm\) 0.1 \\ Caffeic acid & 0.84 \({}^{\text{a}}\)\(\pm\) 0.1 & 1.21 \({}^{\text{b}}\)\(\pm\) 0.2 & 1.64 \({}^{\text{c}}\)\(\pm\) 0.1 & 2.01 \({}^{\text{d}}\)\(\pm\) 0.1 \\ p-Coumaric acid & 0.52 \({}^{\text{a}}\)\(\pm\) 0.1 & 0.73 \({}^{\text{b}}\)\(\pm\) 0.1 & 0.98 \({}^{\text{c}}\)\(\pm\) 0.1 & 1.35 \({}^{\text{d}}\)\(\pm\) 0.2 \\ Ferulic acid & 0.68 \({}^{\text{a}}\)\(\pm\) 0.1 & 0.89 \({}^{\text{b}}\)\(\pm\) 0.1 & 1.14 \({}^{\text{c}}\)\(\pm\) 0.1 & 1.41 \({}^{\text{d}}\)\(\pm\) 0.1 \\ Vanillic acid & 0.47 \({}^{\text{a}}\)\(\pm\) 0.1 & 0.63 \({}^{\text{b}}\)\(\pm\) 0.1 & 0.78 \({}^{\text{c}}\)\(\pm\) 0.1 & 0.93 \({}^{\text{d}}\)\(\pm\) 0.1 \\ Syringic acid & 0.34 \({}^{\text{a}}\)\(\pm\) 0.1 & 0.42 \({}^{\text{b}}\)\(\pm\) 0.2 & 0.54 \({}^{\text{c}}\)\(\pm\) 0.1 & 0.67 \({}^{\text{d}}\)\(\pm\) 0.1 \\ Total phenolics & 4.17 \({}^{\text{a}}\)\(\pm\) 0.3 & 5.56 \({}^{\text{b}}\)\(\pm\) 0.2 & 7.23 \({}^{\text{c}}\)\(\pm\) 0.2 & 9.11 \({}^{\text{d}}\)\(\pm\) 0.1 \\ \hline \hline \end{tabular} Values are mean \(\pm\) standard deviation (n = 3). Different superscript letters in the same row indicate significant differences (\(p<\) 0.05).  
\end{table} 
Table 4: Phenolic profile of cassava root flour naturally fermented using different times. Scanning Electron Microscopy Images of Naturally Fermented Cassava Root Flour Using Different Fermentation Times  
Figure 1A-D presents a series of scanning electron microscopy (SEM) images illustrating the morphological changes in fermented cassava root flour over a 48 h period. These observations provide insights into the structural stability and degradation of starch granules as affected by microorganisms during fermentation.