After preparation, the CD-GO microcapsules appear pale-yellow granules (Figure 1) with a slight garlic flavor, which is enhanced when dissolved by rehydration. The results of measuring the moisture content (%), bulk density (g/cm3), hygroscopicity (g H2O/100 g), and resting angle θ (°) of CD-GO are shown in Table 1, where the low moisture content prevents lipid oxidation, microbial growth and caking in food products (33). The water content of the CD-GO obtained was low, at 5.86 ± 0.47%. Moisture absorption refers to water adsorption on a solid’s surface. A sample with high moisture absorption is susceptible to decreased mobility, solidification, wetting, and liquefaction and may even promote chemical reactions that reduce the stability of the sample. The hygroscopicity of the prepared CD-GO averaged 5.77 ± 0.53. Refer to a study by Bueno et al. (34) on β-CD encapsulated norfloxacin which classified it as moderately hygroscopic (2–15%). The bulk density and angle of repose of a powder reflect the particle-to-particle space size and the powder-type product’s flowability, respectively, both of which are key parameters affecting storage, transport, handling, packaging, and industrialization (32). The bulk density of the prepared CD-GO was 0.58 ± 0.09 g/mL, and the resting angle θ was 32 ± 4.5°.

GC–MS analyzed the garlic oil, and the total ion chromatography (TIC) results are shown in Figure 2, with characteristic peaks appearing after 4, 8, 12 and 15 min, labeled as fractions 1–4. The mass spectra of the components are shown in Figure 2, which were compared with the Smart SIM database and the specific components with more than 90% similarity are shown in Table 2, Mass chromatograph in Figure 3, diallyl monosulfide, diallyl disulfide, diallyl trisulfide and diallyl tetrasulfide. The standard external method, the standard curve calculated by GC–MS, the equation y = 847,527x-186365. the correlation coefficient R^2 = 0.9995, which correlates well.

The results of the particle size distribution of β-CD, the physical mixture, recrystallized β-CD, and CD-GO are shown in Figure 4. The volume distribution in Figure 4A shows that the particle size distribution of β-CD is more extensive, which may be due to their interactions. The larger particle size interval of the physical mixture is due to the addition of GO, which adheres to the cyclodextrin surface, further increasing the viscosity and the aggregation between cyclodextrins. Comparing the volume distribution in Figure 4A with the quantity distribution in Figure 4B, the number of small and medium-sized particles is predominant in each group of powders. At the same time, the recrystallized β-CD and CD-GO have a narrower particle size distribution and will have smaller relative particle sizes than the β-CD powders, a result also reflected in a previous result on the particle size of anisaldehyde inclusion compounds (35). The reduction in particle size can be attributed to the process of inclusion preparation, including dissolution, embedding, co-precipitation and filter drying.

SEM can observe the surface morphology of the material, and the results are shown in Figure 5, Figures 5A–C for the raw β-CD powder, the recrystallized β-CD, and the physical mixture, respectively. However, the CD-GO in Figure 5D shows a significant re-duction in particle size compared to the former, and again the diamond-like lamellar structure is entirely different in shape from the previous three, suggesting the formation of an inclusion complex (36).

Infrared spectroscopy is widely used as an analytical tool to identify compounds and the presence or absence of chemical functions and interactions between mixtures. The structure of the infrared absorption profiles detected for GO, physical mixture, CD and CD-GO is shown in Figure 6.

GO spectra, 3,080, 2,920, 2,851 cm-1 for-CH2 stretching vibrations (37) and 1,464, 721 cm-1 for-CH2 bending vibrations, 1,423–1,398 cm-1 and 1,217 cm-1 for-CH2-CH2 = CH-group stretching vibrations, 1,636 cm-1 for C=C stretching vibrations in the propylene group, and 918 cm-1 for strong and narrow peaks for C-S-C stretching vibrations (38).

The CD spectrum shows a characteristic peak for β-CD, with a broad and robust vibration appearing at 3288 cm-1 as a bending of-OH, 2922 cm-1 as a-CH stretching vibration (35), 1,660 cm-1 as a bending of H-O-H, 1024 cm-1 as a symmetric stretching of C-O-C (39) and 1,155 as a bending vibration of-OH (40).

The results of the Physical mixture hybrid spectrograms are like the superimposed GO and CD spectra, where the characteristic peaks of GO are very distinct in the hybrid spectra, indicating a weak or almost non-existent interaction between GO and CD in the physical mixture. However, some of the GO signals are missing or shifted and weakened in the CD-GO spectrum (7, 8), 918 cm-1\u00B0C-S-C stretching vibrations, 1,217 cm-1-and 3,082-CH2 cm-1 stretching vibrations are missing in the CD-GO spectrum, which may be due to GO being encapsulated in β-CD, resulting in a restricted group vibration that weakens its signal This may be because the GO is wrapped inside the β-CD, resulting in a restricted vibration of the group that weakens its signal (41).

X-ray diffraction is an effective means of detecting β-CD complexation in the powder or micro-crystalline state (42). The crystal structures of β-CD and its inclusions are di-vided into three main categories: channels, cages, and layers. The results of XRD examinations of β-CD, physical mixtures, recrystallized CD and CD-GO are shown in Figure 7. The spectra of β-CD powders show some intense and sharp peaks at diffraction angles of 8.94°, 10.66°, 12.52°, 17.04°, 18.92°, 22.68° and 27.04° at 2θ, and several small peaks at 6.32°, 14.66°, 15.32°, 20.76°, 24.24° and 25.64° at 2θ, confirming that the β-CD has a typical cage-like structure. The diffraction pattern should change significantly if the crystalline shape is affected or altered (43). The diffraction pattern of β-CD recrystallized empty microcapsules showed changes in the intensity of some peaks compared to Physical mixture. No new peaks appeared, indicating that the simple addition of GO Physical mixture did not induce the formation of new compounds or affect the crystal shape of β-CD recrystallized empty microcapsules, like the reported results (35). However, compared to the physically mixed diffraction pattern, some of the peaks present in the physically mixed pattern disappear, maybe because the GO is embedded in the cavity of the β-CD, and the interaction between the subject and the object material leads to different degrees of structural alteration of the β-CD.

TG measures the mass change of a sample during heating or cooling to determine its thermal decomposition or reaction characteristics. Figure 8A shows TG plots for four different materials, recrystallized CD, β-cyclodextrin powder and physically mixed powder before the first stage at 110°C losing 13.1, 13.4 and 12.9% by weight, respectively, due to evaporation of water from inside the β-cyclodextrin cavity (44). The weight loss of CD-GO in the first stage was around 8.3%. The reason for the slow weight loss of the inclusion complex compared to the other three before the first stage was that since the GO replaced the water molecules inside the cavity of the cyclodextrin and was encapsulated inside the cavity, the temperature in the first stage could evaporate the water on the surface of the cyclodextrin material and the water inside, but not enough to eliminate the GO that replaced the water inside the inclusion complex. The variability of the weight loss graphs in the first stage shows that the GO was successfully encapsulated in-side the cyclodextrin. Taking the first-order derivative of the TG data gives a plot of the variation of DTG in Figure 8B. The DTG plot allows a closer look at the thermal effects of the four different materials. The rate of weight loss is most remarkable in the first phase of the physical blend due to the increased rate of weight loss caused by the rapid evaporation of the volatile components of the garlic oil at elevated temperatures. However, the interaction between the garlic oil components and the inner cavity structure of the β-CD in the inclusion complexes mutually enhances the stability of each (45).

DSC allows the thermal analysis of materials to investigate their thermal effects and thermodynamic properties. DSC results are shown in Figure 9. Thus, by combining both techniques, TG and DSC, a more comprehensive understanding of the changes in the properties of the material can be obtained, allowing a more accurate assessment of the outcome of CD-GO inclusion formation. DSC can be used for the identification of inclusion compounds. When guest molecules are embedded in a Raw β-CD cavity, their melting, boiling or sublimation points typically shift to different temperatures or disappear (46). DSC results are shown in Figure 9. CD-GO thermal peak is advanced. This may be due to GO inclusion and CD-GO inside.

Retention is one of the most important indicators of the performance of a slow-release material and Figure 10A shows the results of the retention of pure GO and CD-GO over time at 37°Ch145% humidity for 30 days. Under the test conditions, a sudden release of GO occurred during the first 4 days and evaporated during the subsequent period, where the mass loss exceeded 50%. After 30 days, only 42.19% of the initial weight remained. In contrast, GO encapsulated in the inclusion complex retained a relatively high percentage during the 30 days of storage, remaining at 76.17% at the end. The release capacity of CD-GO was assayed in PBS, at 37°C and 50°C, and the release pattern is shown in Figure 10B.

At different temperatures, the release pattern of CD-GO was that there was a sudden release at first and then a slow release (37), reaching 54.46% in 4 h at 37°C and 74.82% in 2 h at 50°C. This may be due to the absorption of water by CD-GO, which leads to the change of molecular structure of CD, resulting in the dissolution of part of the inclusion compound, and the release of garlic oil (47). A similar release pattern was seen in the β-CD encapsulation study on anisaldehyde (35).

The results of DPPH radical scavenging by CD-GO are shown in Figure 11. Figure 11A shows the DPPH scavenging rate after 30 min of treatment for different concentrations of samples, with increasing antioxidant activity as the concentration of samples increased. At a 75 mg/g concentration, the DPPH scavenging rate of GO reached 73.62%, while that of CD-GO was at 43.96%. Figure 11B shows the results of the change in DPPH clearance over 120 min for the 42.19 mg/g sample, with the cumulative DPPH clearance increasing for both samples as time increased. For the first 75 min, GO was higher than CD-GO regarding DPPH clearance and clearance rate. However, as the time exceeded 75 min, the DPPH clearance in the GO group stopped increasing while CD-GO continued to increase until it reached 70.22% DPPH clearance at 120 min, which was 17.57% higher than GO at 1.32 times the DPPH clearance rate of GO. Existing studies have shown that β-CD alone is not reductive (48), so the reason why CD-GO is more reductive than GO may be that the reducing sulfide component of GO is encapsulated by CD, increasing its solubility and stability, and preventing its volatilization or deactivation. CD-GO, there-fore, exhibits a sustained antioxidant capacity compared to GO. A similar phenomenon was found in encapsulated pairs of anisaldehyde cyclodextrins (35).

Firmness is the most direct indicator of mouthfeel, and in texture profiling, it directly affects chewiness, chewiness, Springiness, and Gumminess (49). The results of the effect of CD-GO on the firmness of plant-based flesh are shown in Figure 12A. The results showed that the firmness of plant-based meat increased with CD-GO addition. Due to the strong adhesive force of dextrin, the plant-based tissue proteins were made to form a dense fibrous mesh structure with each other leading to an increase in the firmness of plant-based meat patties. Chewiness is defined as adhesion multiplied by elasticity. It can be interpreted as the energy required to chew solid food (50). Figure 12B shows the effect of CD-GO on plant meat Chewiness. The results showed that CD-GO increased the chewiness of meatloaf.

Figure 13 shows a plant-based meatloaf under a scanning electron microscope magnified 300 times. Figure 13A shows the meat without added CD-GO, where more gaps are visible and unevenly distributed. Figure 13B is meat with 10% CD-GO added, with a lower number of crevices and a uniform distribution of holes in the cut surface, visible as the formation of a reticulated structure, consistent with the TPA’s speculation that the addition of CD-GO increases the hardness and chewiness of the meat as a result of the formation of a reticulated structure by the dextrin. Adding CD-GO contributes to a more stable and delicate structure of plant-based meat.

Essential oils robust and pungent odor and taste can affect people’s interest in food and its organoleptic qualities (51). The sensory evaluation results are shown in Figure 14 and demonstrate that with or without the addition of CD-GO, it had little effect on the overall appearance and fiber feel of the plant-based meat, scoring within 7–8 like moderately and like a lot (p > 0.05). In terms of odor, the CD-GO group scored the highest at 7.6, followed by the control group with 4.3, and the worst was the blank group with 1. because the garlic oil in the control group was mixed directly into the plant-based meat. The encapsulation of the microcapsules did not mask the odor, and the overpowering odor led to a decrease in the score. The same is reflected in the results of the flavor score item. Finally, the chewiness score showed that both the CD-GO and control groups were close to each other with scores between 7 and 8, indicating that garlic oil at this concentration does not affect the chewiness of the patties; it is the cyclodextrin that affects the chewiness. Adding 10%, CD-GO can effectively improve the flavor and texture of plant-based meat and enhance the value of plant-based meat patties.