Critical Assessment of Various Techniques for the Extraction of Carotenoids and Co-enzyme Q₁₀ from the Thraustochytrid Strain ONC-T18

A variety of techniques for extracting carotenoids from the marine Thraustochytrium sp. ONC-T18 was compared. Specifically, the organic solvents acetone, ethyl acetate, and petroleum ether were tested, along with direct and indirect ultrasonic assisted extraction (probe vs bath) methods. Techniques that used petroleum ether/acetone/water (15:75:10, v/v/v) with 3 h of agitation, or 5 min in an ultrasonic bath, produced the highest extraction yields of total carotenoids (29−30.5 μg g^-1). Concentrations up to 11.5 μg g^-1 of canthaxanthin and 17.5 μg g^-1 of β-carotene were detected in extracts stored for 6 weeks. Astaxanthin and echinenone were also detected as minor compounds. Extracts with and without antioxidants showed similar carotenoid concentration profiles. However, total carotenoid concentrations were approximately 8% higher when antioxidants were used. Finally, an easy-to-perform and inexpensive method to detect co-enzymes in ONC-T18 was also developed using silica gel TLC plates. Five percent methanol in toluene as a mobile phase consistently eluted co-enzyme Q₁₀ standards and could separate the co-enzyme fractions present in ONC-T18.

Keywords: Carotenoids; Thraustochytrium sp. ONC-T18; antioxidants; astaxanthin; canthaxanthin; echinenone; β-carotene; ultrasonic; co-enzyme Q₁₀