Home/Supercritical fluid technology/Study On The Technology Of Extracting Linolenic Acid Oil From Pine Nuts By Supercritical CO2

Study On The Technology Of Extracting Linolenic Acid Oil From Pine Nuts By Supercritical CO2

Pine nut oil

Pine nut oil is taken from the natural red pine seed.

It is a natural and environmentally-friendly green woody vegetable oil. It is a natural bulk product in nature and is inexhaustible for people to develop and utilize.

It not only can increase the variety of edible oils, regulate the nutritional structure of people’s food, but also improve economic benefits. Therefore, the development of pine nut oil has broad prospects.

Features of pine nut oil

Pine nut kernel is rich in unsaturated fatty acids, especially linolenic acid. Lnolenic acid (LNA) has a molecular formula of C18H30O2, which is an essential unsaturated fatty acid with important health care effects.

The traditional scouring process extracts linolenic acid oil from pine nuts, which destroys more biologically active components due to high temperature.

Method for supercritical CO2 extraction of pine nut oil

The supercritical CO2 extraction process utilizes the relationship between the solubility of the supercritical CO2 fluid and its density, that is, the effect of pressure and temperature on the solubility of the supercritical fluid.

Supercritical CO2 extraction of pine nut linolenic acid oil
Supercritical CO2 extraction of pine nut linolenic acid oil

In the supercritical state, the solubility of CO2 to different solutes varies greatly, so it can be effectively extracted and separated.

Supercritical extraction has the characteristics of low operating temperature, good selectivity, complete extraction from extraction to separation, and no residual residue, so it can preserve bioactive components well.

Experimental methods and steps

Experimental methods

Based on several supercritical CO2 experiments, preliminary data of extraction tank pressure and temperature, rectification column temperature and extraction time of linolenic acid extracted from pine nuts were obtained. On this basis, extraction pressure, extraction temperature, extraction time, Four factors of column temperature were determined, and three levels of each factor were determined.

The orthogonal experimental design was carried out by using L9 (34), and the experiment was carried out by using 2L extraction kettle. The extraction and separation process was: extraction kettle – rectification column – separation I – Separation II.

SFE condition optimization

Effect of temperature

When the temperature is increased, on the one hand, the mass transfer rate of the fluid increases, and the solute cohesive energy is lowered to facilitate the desorption of the extract from the substrate; however, the density of the fluid increases correspondingly. Causes a decrease in solvency. Experiments have shown that the optimum extraction temperature is 40 °C.

Influence of pressure

With the increase of pressure, the yield of linolenic acid in pine nuts increases, because the density of fluid increases with the increase of pressure, and the solvency of linolenic acid in pine nuts increases. . The optimum pressure is 35 MPa.

Effect of extraction time

With the increase of extraction time, the yield of linolenic acid in pine nuts increased, but the increase over 1.5h was not very significant.

Effect of column temperature

Experiments showed that the increase of linolenic acid in pine nuts increased with the increase of column temperature, but the extraction rate of linolenic acid in pine nuts decreased after the column temperature increased to 34 °C.

Best supercritical CO2 extraction solution.

The optimal extraction conditions for extracting linolenic acid from pine nuts by supercritical CO2 were: extraction temperature 40 °C, extraction pressure 35 MPa, extraction time 90 min, column temperature 34 °C.

Comparison supercritical CO2 extraction with the refined method

Refined method

The fine pressing method means that the oil material is first ground and crushed, and then the oil is squeezed out, and finally a series of refining and purification are carried out. At present, linolenic acid oil is prepared from pine nuts in China, and this production process is generally adopted. The yield of the extractive extraction method is generally around 21.4%.

Extract analysis

The results showed that the content of unsaturated fatty acids in the extract was as high as 84.8%, and the content of linolenic acid was particularly rich, reaching 34.6%.

Coclusion

The experimental results show that the supercritical CO2 extract has no solvent residue and good color, and the yield of the extract is 34.6%, which is 13.2% higher than the yield of the refined extraction method of 21.4%.

Discussion

  • Supercritical CO2 extraction method was used to extract the linolenic acid oil from pine nuts of Changbai Mountain, Jilin Province, and the extraction yield was higher than that of the refined method.
  • Moreover, the supercritical CO2 fluid extraction operation temperature was low, and the natural active ingredients of heat instability and easy oxide were saved in large amount; The supercritical CO2 fluid extraction method uses CO2 as the extraction medium.
  • The system is closed, safe, non-toxic, and there is no solvent residue problem.
  • The extraction and separation are completed once and the quality of the extracted linolenic acid oil can be guaranteed. It is a good new extraction process. .

Conclusion

  • Extraction of linolenic acid oil from pine nuts by supercritical CO2 The extraction conditions are: extraction temperature 40 ° C, extraction pressure 35 MPa, extraction time 90 min, column temperature 34 ° C.
  • Supercritical CO2 extract has no solvent residue and good color, and its extract yield is 34.6%, which is 13.2% higher than the yield of the refined extraction method.
  • The analysis results of HP6890/HP5973 GC/MS showed that the content of unsaturated fatty acids in the extract was as high as 84.8%, and the content of linolenic acid was especially rich, reaching 34.6%. Pine nut oil can be used as a health care oil with extremely high nutritional value.

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