## 3 Results and Discussion
### Granule Morphology  
The morphology of 16 BRS sample particles was observed to have ring patterns with different particle shapes, recorded as flat, irregular oval, slender rod, and cone shaped (Figure 2), consistent with the findings from a previous study ([PERSON] et al., 2016). All the particles had birefringence without distinct differences under the polarized light, appearing as Maltese crosses (Figure 3). The Maltese crosses were attributed to the existence of the radial alignment of the crystalline structures in the BRS particles, suggesting that intact crystalline structures were retained during the starch extraction. Through SEM analysis, more details of the starch granules, including size and shape, the presence of other compounds, structural integrity, and surface morphology, were analyzed (Figure 4). The BRS granules of the 16 banana cultivars from the three genome groups displayed a wide range of particle sizes (10 \(\upmu\)m-60 \(\upmu\)m) and a tight arrangement. Parts of the BRS granules had smooth and unbroken surfaces, while there were also some having cracks and wrinkles on the surface with sheet fragments attached. This phenomenon may be explained by the fact that during the early postharvest ripening, cell walls consisting of pectin, cellulose, and a small amount of protein were left over the surface after starch degradation ([PERSON] et al., 2016).  
\begin{table}
\begin{tabular}{c c c} \hline
**Cluster** & **Cultivar** & **Genotype** \\ \hline C1 & Meishi 2, Jinfen 1 & AAB, ABB \\  & A-Maiden, Yuejiao 2 & AAB, AAA \\  & B-Guangfen 1 & ABB \\  & A-Meishi 1, Poingo & AAB, AAB \\ C3 & B-Hongjiao 1, Tigua, Yuejiao 1 & AAA, AAB, AAB \\  & C-Kazirakwe, Mpotosoma, Ingagara, \\  & Saba, GN 60A, Zhongjiao 8 & \\ \hline \end{tabular}
\end{table}
Table 3: Results of hierarchical cluster analysis of BRS from 16 banana cultivars at D1 and D7.  
Four groups were created from the 16 BRS samples according to their microstructure at D1. Maiden (AAB), Poingo (AAB), Tigua (AAB), and Hongjiao 1 (AAA) made up the first group with numerous elongated granules. Tigua and Poingo exhibited identical genotypes (AAB), but the presence of a greater number of small particles in Tigua made it more susceptible to enzymatic digestion [32], resulting in wider BRS degradation for Tigua than for Poingo. The particles in Maiden were of a small size and densely arranged with a low degradation. This suggests that the particle sizes and arrangement have an impact on the rate of starch digestion. The second group was distinguished by an oval shape, including [PERSON] 1 (AAB), Meishil (AAB), [PERSON] 2 (AAB), [PERSON] 2 (AAA), Nagagara (AAA), Saba (ABB), and Mpotogoma (AAA) cultivars. The large round starch granules of the AAB genome BRS (except Yuejiao 1) tended to have a low starch degradation. The cultivars with a high percentage of irregular shapes were sorted out and classified into the third group, including Jinfen 1 (ABB), Guangfen 1 (ABB), Kazirakwe (AAA), Zhongjiao 8 (AAA), and GN 60A (AAA) cultivars. The AAA genome BRS (Kazirakwe, Zhongjiao 8, and GN 60A) tended to contain a greater number of small granules, which aligned with the result of high degradation from the BRS analysis (Table 2). These results indicate that the variations in granular morphology might be accredited to the genotypes of the cultivars. Furthermore, the differences in the BRS microstructures among the 16 banana cultivars were likely to affect the physicochemical properties.  
Figure 2: Optical microscopy images (\(\times\)200) of BRS from 16 banana cultivars.  
Figure 4: Scanning electron microscopy images (\(\times\)500) of BRS from 16 banana cultivars.  
Figure 3: Polarized light microscopy images (\(\times\)200) of BRS from 16 banana cultivars.