title: A New Strategy to Refine Crude Indian Sardine Oil.
abstract: Current work aims to develop a refining process for removing phospholipids, free fatty acids (FFA), and metal ions without affecting n-3 polyunsaturated fatty acid (n-3 PUFA) esters present in the crude Indian sardine oil. Sardine oil was subjected to degumming with various acids (orthophosphoric acid, acetic acid, and lactic acid), conventional and membrane assisted deacidification using various solvents (methanol, ethanol, propanol and butanol) and bleaching with bleaching agents (GAC, activated earth and bentonite) and all the process parameters were further optimized. Degumming with 5%(w/w) ortho phosphoric acid, two stage solvent extraction with methanol at 1:1 (w/w) in each stage and bleaching with 3% (w/w) activated charcoal loading, at 80ºC for 10 minutes resulted in the reduction of phospholipid content to 5.66 ppm from 612.66 ppm, FFA to 0.56% from 5.64% with the complete removal of iron and mercury. Under these conditions, the obtained bleached oil showed an enhancement of n-3 PUFA from 16.39 % (11.19 Eicosapentaenoic acid (EPA) + 5.20 Docosahexaenoic acid (DHA)) to 17.91 % (11.81 EPA + 6.1 DHA). Replacing conventional solvent extraction with membrane deacidification using microporous, hydrophobic polytetrafluoroethylene membrane (PTFE), resulted in a lesser solvent residue (0.25% (w/w)) in the deacidified oil. In view of lack of reports on refining of n-3 PUFA rich marine oils without concomitant loss of n-3 PUFA, this report is significant.
authors.affiliation: Department of Chemical Engineering, National Institute of Technology Karnataka.
authors.forename: S
authors.initials: S
authors.lastname: Charanyaa
authors.affiliation: Department of Chemical Engineering, National Institute of Technology Karnataka.
authors.forename: Prasanna D
authors.initials: PD
authors.lastname: Belur
authors.affiliation: Department of Chemical Engineering, National Institute of Technology Karnataka.
authors.forename: I
authors.initials: I
authors.lastname: Regupathi
mesh_terms: D057886:Bleaching Agents; D002606:Charcoal; D004952:Esters / Q000032:analysis*; D005230:Fatty Acids, Nonesterified / Q000302:isolation & purification; D015525:Fatty Acids, Omega-3 / Q000032:analysis*; D005395:Fish Oils / Q000032:analysis* / Q000737:chemistry*; D007477:Ions; D058085:Iron Compounds / Q000302:isolation & purification; D017669:Mercury Compounds / Q000302:isolation & purification; D010743:Phospholipids / Q000302:isolation & purification; D010756:Phosphoric Acids; D011138:Polytetrafluoroethylene; D012997:Solvents; D013696:Temperature
chemical_list: D057886:Bleaching Agents; D004952:Esters; D005230:Fatty Acids, Nonesterified; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D007477:Ions; D058085:Iron Compounds; D017669:Mercury Compounds; D010743:Phospholipids; D010756:Phosphoric Acids; D012997:Solvents; D002606:Charcoal; D011138:Polytetrafluoroethylene; C030242:phosphoric acid
keywords: Sardinella longiceps; bleaching; deacidification; degumming; n-3 PUFA; refining