Method for extracting functional oil from microalgae and emulsions containing said functional oil

Production of Lutein/Zeaxanthin Oil and Emulsions via Ultrasonic Extraction of ZEP/AGP Mutant Chlamydomonas

This technology involves a method for extracting functional oil from the supernatant of centrifuged Chlamydomonas reinhardtii—a mutant strain with specific base insertions/deletions in the ZEP and AGP genes—by adding it to an organic solvent at a ratio of 80–120 mL/g and applying 20–60 kHz ultrasonic treatment. It also covers oil compositions, emulsions, and food compositions made from this oil.

It is difficult to meet the 10mg daily recommended intake of lutein and zeaxanthin for eye health through a standard diet, and marigold flowers, the primary source, are expensive due to low yield per cultivation area and long growth cycles. While research has explored producing lutein from microalgae like Chlorella, these methods often suffer from excessively low zeaxanthin content, making it difficult to obtain sufficient amounts of both pigments.

This technology uses a mutant strain with a deactivated zeaxanthin epoxidase (ZEP) to ensure zeaxanthin accumulates without converting into other pigments. Extraction time is reduced by applying ultrasound at 33–40°C for 140–160 minutes and inducing phase separation with polar solvents like potassium chloride or sodium chloride. The extracted oil is mixed with corn, soybean, sesame, or sunflower oil and emulsified with a pH 3–5 acetic or citric acid buffer and an emulsifier to ensure storage stability. Applicable to eye health supplements for macular degeneration, lutein-fortified dressings and beverages, and microalgae-based carotenoid production, this method allows for the mass production of oil rich in both lutein and zeaxanthin from cultured microalgae, eliminating the need for marigold cultivation.

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Key Features:

• A step of adding a Chlamydomonas reinhardtii mutant strain, containing an insertion mutation between the 816th and 817th bases of the ZEP gene and an AGP gene mutation, to an organic solvent at a ratio of 80 to 120 mL/g
• A step of ultrasonically treating the microalgae-added solution at 20 to 60 kHz and 33 to 40°C for 140 to 160 minutes
• A step of separating functional oil by inducing phase separation with the addition of polar solvents such as potassium chloride or sodium chloride to the supernatant after centrifugation
• An emulsion comprising functional oil containing lutein and zeaxanthin, vegetable oil, an emulsifier, and a buffer solution with a pH of 3 to 5

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This invention was developed with support from the Ministry of Science and ICT for the development of high-efficiency CO2-fixing microalgae through molecular biological improvement.

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