Supercritical Carbon Dioxide Extraction of PUFA Rich Oil from Freeze Dried Tuna Red Meat

Abstract

Supercritical fluid extraction (SFE) is an emerging
technology for extraction and isolation of valuable
compounds from natural products. Supercritical
carbon dioxide (SCO2) is one of the most commonly
used solvents in SFE and has gained importance
as a “green†or environment friendly solvent. In
this study, polyunsaturated fatty acid (PUFA) rich
oil from freeze dried yellowfin tuna (Thunnus
albacares) red meat was extracted using supercritical
carbon dioxide. Red meat, a by-product obtained
from tuna processing forms about 9-11% of the total
body weight of tuna. Lipid extraction from freeze
dried tuna meat was performed at a temperature
of 60oC and pressure of 35 MPa for 3 h. The flow
rate of CO2 was kept constant at 175 l h-1. The
extracted oil was collected in two separators both
held at 5 MPa pressure and temperature of 50oC
and 40oC respectively. The antioxidant tocopherol
(0.5%) was added to the extracted oil and stored
at 2-4oC for further analysis. The yield of oil
obtained was 5% and it was found to be rich in
polyunsaturated fatty acids like docosahexaenoic,
eicosapentaenoic and arachidonic acid constituting
31, 5 and 4% of the total fatty acids respectively.
Palmitic and stearic acid were the most abundant
saturated fatty acids present constituting 23 and
15% of total fatty acids respectively. Oleic acid
contributed 18% of the total fatty acids. SFE was effective in extraction of fatty acids from tuna red meat with minimal losses