Guide to best okra seed oil CO2 extraction process in 2022

Okra is the most edible, medicinal, and health-care function among more than 200 okra plants, and it has a high utilization value. It has broad prospects for its cultivation and development and utilization of active ingredients such as flavonoids.

Okra

Supercritical CO2 extraction okra seed oil
Supercritical CO2 extraction okra seed oil

Okra is an annual herbaceous plant of the genus Okra of the Malvaceae family.

The plant height is 1.5-2.0 meters, with many branches, dark green leaves, bright yellow flowers 16-18 cm in diameter, and round dark brown seeds.

Medicinal

Okra can be used as both food and anther, which can clear heat and cool blood. The fruit and seeds have the functions of invigorating the spleen and stomach and promoting muscle growth. It can treat indigestion, reluctance to eat, and traumatic injuries.

Total flavonoids

Its total flavonoids can significantly regulate human endocrine and immunity, increase human resistance, improve cardiovascular and cerebrovascular and microcirculation functions, and enhance the body’s antioxidant capacity; rich natural phytoestrogens are useful for prolonging female puberty and reducing or avoiding middle-aged menopause. Symptoms also have miraculous effects.

Hyperoside

Okra is also rich in hyperoside, and hyperoside has obvious anti-inflammatory effects, strong cough-reducing effect an assimilation effect.

Okra dried flower contains 37.63mg of flavonoids per gram, okra seed kernels contain 26.013mg of flavonoids per gram, okra seed kernel oil contains VE as high as 1.976mg per gram, and the content of flavonoids and VE is dozens of times that of other plants.

CO2 extraction method

Okra seed→dry at 45℃ to constant weight→crush→supercritical static extraction for 1h→supercritical circulation extraction for 3h→combine the extracts, calculate the extraction rate of okra seed oil→detect the total flavonoid content.

Okra seed oil VE determination method

The content of okraokra seed oil VE was determined by HPLC. The okra seed oil was made into the test solution, and passed through an EP-C18 chromatographic column with methanol as the mobile phase, flow rate 0.3ml/min, injection volume 5μl, column temperature 30 ℃, use UV detector to detect at 285nm, and calculate the content by external standard method.

2 Factors Affecting the Efficiency of Carbon Dioxide Extraction from Okra Seed Oil

When the CO2 flow rate is 12L/h, the extraction pressure is 30MPa, and the extraction temperature is 45°C, the extraction rate of okra seeds is 16.2%.

Temperature

In the experiment, under the conditions of 30 MPa and 12.0L/h of CO2 flow rate, the influence of different extraction temperatures (35, 45, 55 ℃) on 300g of dried okra seeds with a crushing particle size of 100 mesh was investigated.

With the increase in extraction temperature, the extraction amount of okra seeds oil showed a logarithmic trend with the increased extraction time. When the extraction temperature is 45 ℃, the extraction rate of sunflower seeds reaches the maximum.

This is because the increase in temperature will lead to a decrease in the density of the supercritical fluid on the one hand, which is not conducive to the co2 extraction process of solutes; on the other hand, the increase in temperature is conducive to the increase of the mass transfer rate and accelerates the extraction process. Therefore, the appropriate extraction temperature was selected as 45 ℃ in this experiment.

Pressure

The experiment investigated the influence of different extraction pressures (20, 25, 30 MPa) under the conditions of 45°C and a CO2 flow rate of 12.0 L/min.

With the increase of extraction pressure, the extraction volume of okra seeds oil increases logarithmically. When the extraction pressure is 30MPa, the extraction rate of okra seed oil reaches the maximum.

This is due to the increase in pressure. On the one hand, the density of the supercritical fluid increases, which is conducive to the extraction of the solute; on the other hand, the increase in pressure is conducive to the increase of mass transfer rate and accelerates the extraction process.

Therefore, this experiment chooses the appropriate extraction temperature to be 30MPa.

Time

In the experiment, under the conditions of 30MPa, 45°C, and a CO2 flow rate of 12.0L/min, the oil output of okra seeds oil in different extraction time periods were investigated. The oil yield of okraanihot seeds in the first 60 minutes of extraction is high; with the extension of the extraction time, the extraction volume of okra seeds increases logarithmically; after 150 minutes, the oil yield of okra seeds does not increase significantly, so the extraction The rate is increasing slowly. Therefore, this experiment chooses the appropriate extraction time as 150 min.

Okra co2 extraction process

  • Extraction pressure: 300 bar;
  • Extraction temperature: 45°C;
  • Separation pressure: 90 bar;
  • Separation temperature: 55 °C
  • Extraction time: 90 min.

Through this experiment, we can get:

Using SCF to extract okra oil at an extraction pressure of 30 MPa, an extraction temperature of 45 ℃, and an extraction time of 2.5 hours, the best extraction rate of sunflower oil can be obtained. ;

Under this technological condition, the effective ingredient VE in okra can be extracted, and it is detected to be 23.0mg/100g.
SCF extraction technology can be used for okra oil extraction. A slight improvement in the extraction process can increase the VE yield. If ethanol is added as an entrainer, the effective ingredient flavonoids can be extracted.

The okra seeds oil produced by this process has good solubility and dispersibility, is easily fully absorbed by the human body, has no solvent residue, and is beneficial to health. It is another important extraction technology for okra oil extraction and has application value.