## 3 Results
### Reusability and Applicability of CALB@MCM-41-C\({}_{\rm{8}}\)  
The reusability of CALB@MCM-41-C\({}_{\rm{8}}\) is an important index that is used to assess its long-term and economic benefits. The results show that the relative activity of CALB@MCM-41-C\({}_{\rm{8}}\) remained above 90% in six cycles, as the final acid values of high-acid rapeseed oil were kept below 3 mg KOH/g (Figure 6a). The findings confirm that MCM-41-C\({}_{\rm{8}}\) served as an ideal carrier to maintain the catalytic ability of lipase CALB and promote the utilization stability of immobilized lipase, thus demonstrating its potential implementation in industrial-scale applications. The broad applicability of CALB@MCM-41-C\({}_{\rm{8}}\) is studied based on its catalytic performance to deacidify various types of high-acid vegetable oils such as high-acid value tea seed oil (TSO), high-acid value rice bran oil (RBO), and high-acid value soybean oil (SO) (Figure 6b). With the use of CALB@MCM-41-C\({}_{\rm{8}}\) in optimal reaction conditions, the acid values of high-acid value tea seed oil, high-acid value rice bran oil and high-acid value soybean oil were continually decreased from 16.3 mg KOH/g, 9.3 mg KOH/g, and 6.9 mg KOH/g to 1.3 mg KOH/g, 1.9 mg KOH/g, and 2.0 mg KOH/g, respectively. Based on the results, the deacidified oils could meet the acid value demand of edible oil standard; therefore, CALB@MCM-41-C\({}_{\rm{8}}\) is applicable for enzymatic deacidification for different vegetable oils [7].  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Serial Number**} & \multirow{2}{*}{**Volatile Compounds**} & \multirow{2}{*}{**Odor**} & \multicolumn{2}{c}{**Aroma Content of Rapeseed Oil (\(\mu\)g/kg)**} \\ \cline{3-5}  & & & **Commercialized** & **Rapeseed Oil** & **High-Acid** \\ \hline \multicolumn{5}{c}{**Acids**} \\ \hline
1 & Acetic acid & & \(7.00\pm 1.00\) & \(3.39\pm 0.08\) & \(0.32\pm 0.03\) \\ \hline
2 & Propionic acid & & \(0.24\pm 0.03\) & \(0.04\pm 0.00\) & n.d. \\ \hline
3 & Hexanoic acid & & n.d. & \(2.32\pm 0.03\) & n.d. \\ \hline
4 & Pelargonic acid & & n.d. & \(1.32\pm 0.04\) & n.d. \\ \hline \multicolumn{5}{c}{**Subtotal**} \\ \hline
**Ketones** & & & & \\ \hline
1 & 5-Methylfuranone & & \(0.43\pm 0.01\) & \(0.14\pm 0.01\) & n.d. \\ \hline
2 & Furanone & & \(0.17\pm 0.17\) & \(0.14\pm 0.04\) & \(0.09\pm 0.00\) \\ \hline \multicolumn{5}{c}{**Subtotal**} \\ \hline
**Alcohols** & & & & \\ \hline
1 & Isopropanol & & \(0.53\pm 0.09\) & n.d. & n.d. \\ \hline
2 & Phenylethanol & & \(0.15\pm 0.01\) & \(0.02\pm 0.00\) & n.d. \\ \hline
3 &
\begin{tabular}{c} 5-Methyl-2- \\furanformaldehyde \\ \end{tabular} & Mellow, malty & & \(0.94\pm 0.04\) & \(0.28\pm 0.03\) & \(0.20\pm 0.04\) \\ \hline
4 & Cyclobutanol & & \(0.26\pm 0.02\) & \(0.28\pm 0.01\) & \(0.10\pm 0.00\) \\ \hline \multicolumn{5}{c}{**Subtotal**} \\ \hline
**Phenols** & & & & \\ \hline
1 & Y-butyrolactone & & \(1.76\pm 0.07\) & \(1.24\pm 0.01\) & \(0.65\pm 0.03\) \\ \hline
2 & 4-Vinyl-2-methoxyphenol & & \(0.08\pm 0.03\) & \(0.10\pm 0.04\) & n.d. \\ \hline
3 &
\begin{tabular}{c} 4-Vinyl-2,6- \\dimethoxyphenol \\ \end{tabular} & n.d. & \(1.73\pm 0.00\) & \(1.10\pm 0.01\) \\ \hline
**Subtotal** & & & \(1.84\) & \(3.07\) & \(1.75\) \\ \hline
**Total** & & & \(47.12\) & \(34.35\) & \(44.39\) \\ \hline \end{tabular} Note: n.d. represents the volatile compounds that cannot be detected in different oil samples.  
\end{table}
Table 2: _Cont._