Table 2.
Effect of the length of fatty acid chain on the biocatalytic synthesis of xylityl monoacyl (XME) and xylityl diacyl (XDE) esters after 90 min of reaction in solvent-free systems under ultrasound assistance (70% ultrasound amplitude) at 40 °C.
| Entry | FFA | Xylitol: FFA molar ratio | XME (%) | XDE (%) | Conv. (%) |
|---|---|---|---|---|---|
| 1 | Caprylic cida | 1:1 | 45.1 | 2.0 | 47.2 |
| 2 | Caprylic acida | 1:2 | 56.1 | 5.4 | 61.5 |
| 3 | Capric acidb | 1:1 | 77.0 | 7.0 | 83.9 |
| 4 | Capric acidb | 1:2 | 68.7 | 9.7 | 78.4 |
| 5 | Lauric acidc | 1:1 | 72.8 | 24.0 | 96.8 |
| 6 | Lauric acidc | 1:2 | 63.8 | 23.3 | 87.1 |
| 7 | Myristic acidd | 1:1 | 39.00 | 9.22 | 48.20 |
| 7 | Myristic acidd | 1:2 | 31.63 | 9.65 | 41.28 |
Melting points: a, 16.7 °C; b, 31.6 °C; c, 43.8 °C; d, 54.4 °C.