## 4 Conclusions  
In the application of LBI to the sedimentation process of sesame oil, two types of scattering effects were observed. The first was a typical scattering spot at the oil's surface, and the second was a Tyndall effect with an increasingly extended path as the sedimentation process continued. The scattering spot at the surface of the oil should be more suitable for monitoring the early stage of diluted sedimentation while the Tyndall effect should be better suited for monitoring the entire process. The crude sesame oil sedimentation process consists of at least two stages: diluted sedimentation and hindered sedimentation. In this study, the sedimentation speed was about \(-\)7 mm/h during the diluted sedimentation stage and then dropped to less than \(-\)2 mm/h, indicating the transition into the hindered sedimentation stage. During the sedimentation process, three factors influenced the oil properties: settling of the particles, oxidation, and hydrolysis. The low change in vitamin E content may be due to the antioxidants of the sesame oil. It is implied that when the volume of a sedimentation tank is fixed, increasing the cross-section and decreasing the height can speed up the sedimentation process and benefit the application of low-cost laser backscattering technology. For producers who make unrefined sesame oil, confirming the diluted sedimentation stage can help them control the time when the customer will see the sedimentation. The laser's power was 1 mW in the continuous LBI measurement. Further research could use a higher-power laser source to enhance both the scattering on the oil surface and the Tyndall effects inside the oil. Additionally, experiments with more plant oil varieties could be conducted to extend the applicability of the LBI technology. It is worth noting that the sedimentation tank design method was greatly improved in the field of wastewater treatment. People interested in plant oil sedimentation may benefit from the similarity between these two processes. \begin{table}
\begin{tabular}{c c c} \hline
**Parameter** & **Day 0** & **Day 30** \\ Ash content (\%, m/m) & 0.84 \({}^{\mathrm{a}}\)\(\pm\) 0.02 & 0.00 \({}^{\mathrm{b}}\)\(\pm\) 0.00 \\ Phosphorus content (mg/kg) & 921 \({}^{\mathrm{a}}\)\(\pm\) 13 & 4.8 \({}^{\mathrm{b}}\)\(\pm\) 0.0 \\ Carbon residue (\%, m/m) & 2.68 \({}^{\mathrm{a}}\)\(\pm\) 0.04 & 0.34 \({}^{\mathrm{b}}\)\(\pm\) 0.00 \\ Total contamination (mg/kg) & 48,170 \({}^{\mathrm{a}}\)\(\pm\) 1836 & 71 \({}^{\mathrm{b}}\)\(\pm\) 9 \\ Water content (\%, m/m) & 0.86 \({}^{\mathrm{a}}\)\(\pm\) 0.02 & 0.09 \({}^{\mathrm{b}}\)\(\pm\) 0.00 \\ Oxidation stability (h) & 19.8 \({}^{\mathrm{a}}\)\(\pm\) 0.2 & 9.6 \({}^{\mathrm{b}}\)\(\pm\) 0.1 \\ \(\gamma\)-Tocorphenyl (\(\mu\)g/g) & 1.106 \({}^{\mathrm{a}}\)\(\pm\) 0.108 & 0.858 \({}^{\mathrm{b}}\)\(\pm\) 0.088 \\ \(\delta\) -Tocopherol (\(\mu\)g/g) & 5.200 \({}^{\mathrm{a}}\)\(\pm\) 0.512 & 4.717 \({}^{\mathrm{a}}\)\(\pm\) 0.272 \\ \(\gamma\)-Tocopherol (\(\mu\)g/g) & 333.32 \({}^{\mathrm{a}}\)\(\pm\) 26.07 & 314.80 \({}^{\mathrm{a}}\)\(\pm\) 12.59 \\ Acid value (mg KOH/g) & 0.98 \({}^{\mathrm{a}}\)\(\pm\) 0.02 & 1.82 \({}^{\mathrm{b}}\)\(\pm\) 0.03 \\ \hline \end{tabular} Note: Values are means of replications \(\pm\) standard deviation. Values in the same row with the same letter are not significantly different at \(p<\) 0.05.  
\end{table} 
Table 2: Chemical values of sesame oil measured before (Day 0) and after sedimentation (Day 30). **Author Contributions:** Conceptualization, Z.W. and S.R. ; methodology, Z.W., S.R. and K.I. ; software, Z.W. ; validation, Z.W. ; formal analysis, Z.W. ; investigation, Z.W. ; resources, Z.W. and S.R. ; data curation, Z.W. ; writing--original draft preparation, Z.W. ; writing--review and editing, Z.W., S.R., K.I. and J.M. ; visualization, Z.W. and S.R. ; supervision, S.R. and J.M. ; project administration, S.R. ; funding acquisition, S.R. and J.M. All authors have read and agreed to the published version of the manuscript.