3.4. SFE-US
Table 3(B) presents the results obtained for SFE-US at the conditions determined by the experimental design, for global yield,phenolic content, and antioxidant activity.
3.4.1. Global yield (X0)
The highest SFE global yield (9.87 ± 0.40%) was achieved at 25 MPa, 50◦C, and ultrasound power of 400 W. The increase of X0with pressure is explained by the increased density of CO2, which enhances its solvation power [5]. Moreover, an increased X0 is observed when ultrasound was applied during SFE. This behavior is consistent with those observed in former works [28]. According to Balachandran et al. [12], the increase of global yield can be attributed to the high extraction rates achieved in the process assisted by ultrasound. The application of ultrasound causes ruptures in the vegetal structure, promoting the release of compounds that were not formerly available, so the yield can be increased. Another possible effect of ultrasound in SFE is the release of extractable material onto the sample’s surface [13]. In this case, the desorption of solute from the substrate to the solvent is enhanced, increasing mass transfer and yield. Also in Table 3, it can be observed that the lowest yield (6.25 ± 0.16%) was obtained at 15 MPa, 60◦C, and 200 W. Such results can be explained by the reduction of CO2 density with decreased pressure, but also with the increase in temperature [29].
Comparing SFE with the low pressure extraction, it can be notedthat Soxhlet with ethanol achieved higher yields, which can be attributed to the extraction of polar compounds that are not soluble in CO2. Moreover, the longer extraction times and solvent to solid proportion also help increasing yield. The low pressure extraction methods are effective, but present disadvantages such as high required volume of solvent, long process tim
3.4. SFE-US Table 3(B) presents the results obtained for SFE-US at the conditions determined by the experimental design, for global yield,phenolic content, and antioxidant activity.3.4.1. Global yield (X0)The highest SFE global yield (9.87 ± 0.40%) was achieved at 25 MPa, 50◦C, and ultrasound power of 400 W. The increase of X0with pressure is explained by the increased density of CO2, which enhances its solvation power [5]. Moreover, an increased X0 is observed when ultrasound was applied during SFE. This behavior is consistent with those observed in former works [28]. According to Balachandran et al. [12], the increase of global yield can be attributed to the high extraction rates achieved in the process assisted by ultrasound. The application of ultrasound causes ruptures in the vegetal structure, promoting the release of compounds that were not formerly available, so the yield can be increased. Another possible effect of ultrasound in SFE is the release of extractable material onto the sample’s surface [13]. In this case, the desorption of solute from the substrate to the solvent is enhanced, increasing mass transfer and yield. Also in Table 3, it can be observed that the lowest yield (6.25 ± 0.16%) was obtained at 15 MPa, 60◦C, and 200 W. Such results can be explained by the reduction of CO2 density with decreased pressure, but also with the increase in temperature [29]. Comparing SFE with the low pressure extraction, it can be notedthat Soxhlet with ethanol achieved higher yields, which can be attributed to the extraction of polar compounds that are not soluble in CO2. Moreover, the longer extraction times and solvent to solid proportion also help increasing yield. The low pressure extraction methods are effective, but present disadvantages such as high required volume of solvent, long process tim
การแปล กรุณารอสักครู่..
