Seed oil of
Therefore, we optimized the factors of extraction technology to increase the yield of oil and the concentration of linoleic acid by single-factor test and orthogonal test.
The seeds of
The method of HPLC (high-performance liquid chromatography) was performed by using the Shimadzu LC-20AT HPLC system with an LC-20AT infusion pump, CTO-10AS column oven, SPD-20A UV detector, LC-Solution chromatographic data analysis system, and Athena C30 chromatographic column.
According to references [
Flow chart of
The oil yield can be calculated by using the following formula:
In addition, two steps were conducted for refining the oil extract technology. In the first step, three comparatively ideal levels of the four factors were obtained by a series of single-factor tests. And then, an orthogonal test with four factors and three levels was employed to determine the optimal technology.
The standard of linoleic acid was weighed preciously, dissolved in the methanol as mother liquor. After that, the mother liquor was diluted into a series of standard solutions with 3.80, 2.28, 1.52, 0.76, and 0.38 mg/mL, respectively. The standard solutions and samples of extracted oil were all chromatographically analyzed on a PLATINUM C30 column (4.6 mm × 250 mm, 5
According to the previous research [
HPLC chromatograms of standard substance and
In order to test the suitability of the method, repeatability, stability, precision, and recovery tests were examined based on the previous HPLC condition: Six oil samples extracted from the One reference solution was tested 6 times in order to test the precision and a desired result (RSD = 0.81%) was achieved In order to test the stability of the method over time, one oil sample was detected at 0, 4, 8, 12, 16, 20, and 24 h, respectively, and the result showed that the examine result (RSD = 2.68%) would remain stable at least 24 h Six oil samples with 80% more standard linoleic acid were tested, and the average rate of recovery and RSD were 98.70% and 1.13%, respectively
According to the evaluation of the method, the results indicated that the HPLC condition was qualified for the analysis of linoleic acid in the oil.
The standard curve for analysis of linoleic acid was obtained in the equation,
As shown in Figure
Effect of liquid-seed ratio on the yield of
The extraction temperatures were investigated and the results are shown in Figure
Effect of extraction temperature on the yield of
The relationship between oil yield and extraction time is shown in Figure
Effect of extraction duration on the yield of
In Figure
Effect of the grinding degree on oil yield of
Based on the result of the single-factor analysis, three levels of the liquid-seed ratio (
The factors and levels of orthogonality experiment for the
Levels |
|
|
|
|
---|---|---|---|---|
1 | 7 : 1 | 40 | 1 | 40 |
2 | 8 : 1 | 35 | 1.5 | 50 |
3 | 9 : 1 | 30 | 2 | 60 |
In order to compare the different effect of the two extraction technologies on the total yield, statistical analysis of oil production was conducted and the results are shown in Table
Significant analysis of the oil yield in the second extraction process.
Average extraction rate of the 1st extraction step | The 2nd extraction step | ||||
---|---|---|---|---|---|
Average extraction rate | Standard deviation |
|
d |
|
|
33.51% | 7.86% | 1.06% | 38.53 | 26 | 2.479 |
The test result showed that the second extraction process could increase the extraction rate by 7.86% significantly through the
The K
In Table
Analytical results of orthogonality experiment.
序号 |
|
|
|
|
Yield1 (%) | Yield2 (%) | Linoleic acid (mg/g) |
---|---|---|---|---|---|---|---|
1 | 1 | 1 | 1 | 1 | 31.62 | 39.49 | 33.44 |
2 | 1 | 2 | 2 | 2 | 33.19 | 41.86 | 47.92 |
3 | 1 | 3 | 3 | 3 | 34.73 | 42.83 | 58.09 |
4 | 2 | 1 | 2 | 3 | 35.33 | 43.78 | 56.24 |
5 | 2 | 2 | 3 | 1 | 31.65 | 38.42 | 43.02 |
6 | 2 | 3 | 1 | 2 | 32.69 | 42.03 | 39.97 |
7 | 3 | 1 | 3 | 2 | 35.21 | 42.55 | 38.44 |
8 | 3 | 2 | 1 | 3 | 36.47 | 43.47 | 54.00 |
9 | 3 | 3 | 2 | 1 | 30.67 | 37.89 | 41.71 |
|
|||||||
K11 | 33.18 | 34.05 | 33.59 | 31.31 | |||
K21 | 33.22 | 33.77 | 33.06 | 33.70 | |||
K31 | 34.12 | 32.70 | 33.87 | 35.51 | |||
K12 | 41.39 | 41.94 | 41.67 | 38.60 | |||
K22 | 41.41 | 41.25 | 41.18 | 42.14 | |||
K32 | 41.30 | 40.92 | 41.27 | 43.36 | |||
K1linoleic | 46.49 | 42.71 | 42.47 | 39.39 | |||
K2linoleic | 46.41 | 48.31 | 48.62 | 42.11 | |||
K3linoleic | 44.72 | 46.59 | 46.52 | 56.11 | |||
|
0.94 | 1.35 | 0.81 | 4.20 | |||
|
0.11 | 1.02 | 0.49 | 4.76 | |||
Rlinoleic | 1.77 | 5.61 | 6.15 | 16.72 |
Through the range analysis of the orthogonality experiment, the corresponding production strategies are listed in Table
The production strategies of the extraction technology based on the orthogonality experiment.
|
|
|
| |
---|---|---|---|---|
Yield of once extraction technology | 9 : 1 | 35 | 1 | 60 |
Yield of twice extraction technology | 8 : 1 | 40 | 1.5 | 60 |
Concentration of linoleic acid | 7 : 1 | 30 | 2 | 60 |
In order to confirm the importance of these factors, variance analysis was conducted after the orthogonal test and the results are listed in Table
Variance analysis of the orthogonality experiment.
SSE1 | SSETotal |
|
|
|
|
|
|
---|---|---|---|---|---|---|---|
Total deviation | 106.69 | 130.28 | 26 | 7.75 |
6.45 |
2.13 | 2.97 |
Mean deviation | 97.16 | 116.30 | 8 | 22.93 |
18.71 |
2.51 | 3.71 |
Error deviation | 9.53 | 13.98 | 18 | — | — | — | — |
|
5.02 | 0.06 | 2 | 4.74 |
0.04 | 3.55 | 6.01 |
|
9.23 | 4.89 | 2 | 8.72 |
3.15 | 3.55 | 6.01 |
|
2.99 | 1.22 | 2 | 2.82 | 0.79 | 3.55 | 6.01 |
|
79.92 | 110.12 | 2 | 75.44 |
70.87 |
3.55 | 6.01 |
The extreme significance of the total deviation and mean deviation revealed that the four factors considered in this paper could actually affect the oil yield of
In this paper, the single-factor test and the orthogonal test were used to optimize the oil extraction technology from the seed of
All original data used to support the findings of this study are included within the supplementary information file.
All authors declare that there are no conflicts of interest regarding this study.
This work was supported by the Scientific and Technological Project of Henan Province (192102110214), International Cooperation Project of Kaifeng Science & Technology Bureau (1806004), and Undergraduate Training Program for Innovation and Entrepreneurship in Henan University Minsheng College (MSCXCY2017065).
The data used to support the findings of this study are provided. The first part: the data for the single-factor test. The second part: the data for the orthogonal test.