*3.5. Thermal Analysis*

Figure 12a–c shows the TGA analysis of the bio-composite samples. Similar trends are observed in all the samples with variable temperatures. However, the graphs indicate that weight loss is reduced, due to the higher fenugreek percentage at elevated temperatures. Initially, 5% of weight loss is observed, because of moisture evaporation as the temperature changes from 25 to 100 ◦C [47,48]. Moreover, cellulose decomposes rapidly at around 350 ◦C because of the removal of hemicelluloses. Only about 30% weight is left for the pyrolysis of the cellulose skeleton at 350 ◦C [49].

**Figure 11.** XRD analysis of the bio-composite samples at various ratio of fenugreek (**a**) 5%, (**b**) 10%, and (**c**) 15%.

**Figure 12.** TGA analysis of the bio-composite samples at various ratios of fenugreek (**a**) 5% (**b**) 10% and (**c**) 15%.

#### *3.6. Antibacterial Activity*

The antibacterial analysis of the bio-composite samples against *Staphylococcus aureus* is seen in Figure 13a–c. The samples showed some form of antibacterial activity against *Staphylococcus aureus,* due to the presence of active phytocompounds shown in FTIR analysis. The antibacterial performance was obtained due to the presence of fenugreek. Reducing and/or capping agents containing phytochemicals may be present in the samples, which kill the virus. Moreover, inherent antibacterial activities may also be present in those botanic compounds. In addition, different types of metabolites such as alkaloids, terpenoids, tannins, flavonoids, and glycosides are available in fenugreek. These metabolites have antibacterial properties which make fenugreek active against bacterial strains [50].

**Figure 13.** Antimicrobial analysis of the bio-composite samples at various ratio of fenugreek (**a**) 5%, (**b**) 10%, and (**c**) 15%.

#### **4. Conclusions**

Starch-based bio-composite films with varying percentages of fenugreek were successfully developed, using vinegar and glycerin. The properties of the bio-composite films were significantly affected by the concentration percentages of fenugreek. It was observed from the biodegradability test that a maximum of 62.5% of the bio-composite film was biodegraded in only 30 days. Lower percentages of fenugreek distributed properly in the film resulted in higher mechanical strength. Higher percentages of fenugreek led to the formation of an amorphous structure of bio-composite films, confirmed with XRD analysis. Thermal stability was assured for the synthesized bio-composites by thermal analysis. Some samples showed antimicrobial activity against *Staphylococcus aureus* bacteria, which confirmed the usability of the synthesized bio-composites in packaging applications.

**Author Contributions:** Conceptualization, N.H. and M.A.C.; methodology, T.I.N.; software, M.M.R. (Md. Masud Rana); validation, M.H.A., M.S.A. and N.H.; formal analysis, M.A.C., K.A.A. and M.M.R. (Md. Masud Rana); investigation, M.A.C., K.A.A., M.D.A. and M.M.R. (Md. Masud Rana); resources, M.A.C., K.A.A., R.S.A., M.D.A. and M.M.R. (Mohammed M. Rahman); data curation, K.A.A., M.A.C., R.S.A., M.D.A. and M.M.R. (Mohammed M. Rahman); writing—original draft preparation, N.H.; writing—review and editing, K.A.A., M.A.C., M.D.A. and M.M.R. (Mohammed M. Rahman); visualization, K.A.A., M.A.C., M.D.A. and M.M.R. (Mohammed M. Rahman); supervision, M.A.C.; project administration, M.A.C., K.A.A., M.D.A. and M.M.R. (Mohammed M. Rahman); funding acquisition, K.A.A., R.S.A., M.D.A. and M.M.R. (Mohammed M. Rahman). All authors have read and agreed to the published version of the manuscript.

**Funding:** Deanship of Scientific Research at Umm Al-Qura University for supporting this work with Grant Code: 22UQU4290372DSR06.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Data will be available upon reasonable request.

**Acknowledgments:** The authors would like to thank the Deanship of Scientific Research at Umm Al-Qura University for supporting this work with Grant Code: (22UQU4290372DSR06).

**Conflicts of Interest:** The authors declare no conflict of interest.
