## 3 Results and Discussion
### X-Ray Diffraction Analysis  
Figure 2a suggests that the sharp peak diffraction feature and the diffuse diffraction feature correspond to the crystalline region and the amorphous region of the starch granules, respectively. The C exhibited relatively strong diffraction characteristic peaks at diffraction angles of 15.0\({}^{\circ}\), 17.0\({}^{\circ}\), 17.9\({}^{\circ}\), and 23\({}^{\circ}\), which belonged to the typical A-type crystalline structure and possessed relatively high stability [35]. No new crystallization peaks emerged after the ultrasonic treatment, and the difference between the C and the US was not  
Figure 1: Microstructures of broken rice starch (**a**), ultrasound-modified starch (**b**), and modified starch composites (**c**). After ultrasound treatment, depressions, pores, and channels can be observed on the starch granules (blue arrow).  
significant. Given that the fillers in the crystalline and amorphous parts of starch granules are different, their sensitivity levels to ultrasound vary. Consequently, it can be inferred that the ultrasonic treatment mainly takes place in the amorphous region of the starch, representing a physical modification process [37]. [PERSON] et al. also found that the amorphous region of starch was destroyed by ultrasound instead of the crystalline region based on the XRD analysis [38]. These data indicate that ultrasonic disruption tends to occur preferentially in the amorphous regions of the starch granule structure [39].  
As shown in Figure 2b, the diffraction peaks of quercetin in the US-Q are present at 10.7\({}^{\circ}\), 12.4\({}^{\circ}\), and 27.1\({}^{\circ}\), and distinct diffraction peaks appear at 7.0\({}^{\circ}\), 13.4\({}^{\circ}\), and 20.1\({}^{\circ}\). This indicates that the combined modification with ultrasound and quercetin has an impact on both the crystalline and amorphous regions of starch granules. Diffraction peaks of the V-type crystalline structure emerge, further suggesting that there is an interaction between quercetin and starch; that is, V-type starch is formed, indicating the formation of an inclusion complex. In another study, the amylose-proanthocyanidin complex showed a prominent peak at 19.8\({}^{\circ}\), indicating that this complex was a V-type crystal inclusion complex [40]. Based on a similar principle, this demonstrates that there may be an interaction between quercetin and starch molecules, resulting in the formation of a V-type crystal inclusion complex. The relative crystallinity rates of C, US, and US-Q are 20.83%, 20.00%, and 19.28%, respectively. The crystallinity of the US-Q is lower than that of the C, indicating that the combined modification with ultrasound and quercetin disrupts the long-range ordered structure of the starch, and a short-range ordered structure is formed from amylose. This may be because the addition of quercetin introduces hydroxyl groups that are prone to binding with starch molecules through hydrogen bonds, thereby affecting the aggregation among the starch molecules. Similarly, [PERSON] et al. showed that a combination of moist heat treatment and ultrasonic treatment could destroy amylopectin crystals, resulting in an unstable lamellar arrangement of starch granules, which is manifested by a decrease in short-range ordering and long-range ordering [41].