Methods used for oleoresin oil extraction and why SCFE is a better technique

Two methods are mainly used for oleoresin extraction or oleoresin oil extraction:

• Supercritical Fluid Extraction (SCFE)
• Solvent Extraction 

A blend of spice and oil that is naturally available in plants, oleoresins counter multiple health conditions such as:

• Cancer Risk
• Muscle and Joint Ache
• Rheumatism
• Diarrhea Risk
• Flatulence
• Digestive Problems
• Infections in the Urinary Tract

Oleoresins can deliver these health benefits only if extracted in their pure form. This is important because they are vulnerable to:

• Heat
• Light
• Oxidation

Solvent extraction uses a solvent to dissolve the oleoresin from the raw material. Evaporation or purging separate the solvent from the oleoresin. The separation is not 100% complete. Therefore, traces of the solvent remain associated with the oleoresin, something which negatively affects its purity. 

Besides, the method sometimes uses heat for better dissolution of the oleoresin in the solvent. This can change the chemical composition of the oleoresin being extracted - oleoresins being vulnerable to heat as we have noted earlier. The use of heat is also the main challenge with the hydrodistillation method that may occasionally be used to extract oleoresins. 

On the contrary, the dissolution and separation action of the supercritical fluid extraction (SCFE) process is based on pressure difference. It uses a supercritical fluid (SCF) that:

• Dissolves the oleoresin from the raw material at high pressure; and

Releases the same oleoresin from solution at low pressure. 

An SCF is a fluid that is at a:

• Pressure above its critical pressure; and

Temperature more than its critical temperature. 

When carbon dioxide (CO2) is used as the SCF for oleoresin extraction and oleoresin oil extraction via SCFE, an additional advantage is harnessed - low temperature. This is because the critical temperature of CO2 is as low as 31.1 deg-Celsius. As a result, the process temperature remains low and avoids thermal distortion i.e. the change in chemical composition of the oleoresin under the action of heat. 

At a particular pressure, the SCF can extract one particular product (oleoresin in this case) from the raw material. Little or no quantities of other products get dissolved in it. As a result, precision is built into the very action of SCFE. This is why SCFE delivers pure oleoresin extraction and oleoresin oil extraction. 

Oleoresins are used in the following industries:

• Food and Beverage
• Personal Care
• Pharmaceutical
• Nutraceutical

Following are among the most common sources of oleoresins:

• Paprika
• Turmeric
• Herbs
• Ginger
• Capsicum
• Cinnamon and Cassia
• Seed Spices