Tra Catfish Oil Production: Phospholipid Removal Using Citric Acid and Bleaching Using Activated Carbon

Tra catfish (Pangasianodon hypophthalmus) is widely cultivated in the Mekong Delta Region, Vietnam, with mainly production of frozen fillets. Crude oil was extracted from tra catfish fat, a by-product, by hot water. Crude oil has phosphorus content of 18.1 mg/kg, Abs $_{\mathbf {228nm}}$of 1.07, melting and solidification points of 33.8$^{\mathbf {o}}\textbf{C}$ and 24$^{\mathbf {o}}\textbf{C}$, respectively. After treatment stages (degumming using citric acid, neutralization, winterization, dewaxing, bleaching using activated carbon and deodorization), chemical and physical properties of refined oil have many advantaged changes. Respectively, phosphorus content, Abs$_{\mathbf {228nm}}$, melting and solidification points were reduced to 3.84 mg/kg, 0.52, $10.2 ^{\circ}\mathrm {C}$ and $- 2.0 ^{\circ}\mathrm {C}$. Besides, quality parameters such as peroxide value (2.66 m.eq/kg), iodine value (66.85 g/100g), and saponification value (152 mg KOH/g) were analytical measurements. Moreover, total content of unsaturated fatty acid was 59.7% including palmioleic, oleic, linoleic, $\gamma $-linolenic, paullinic, eicosadienoic, dihomo-$\gamma $-linolenic, erucic acids. Refined tra catfish oil is pale yellow, liquid state at ambient temperature without strange odor. Obviously, our treatments elevated quality of tra catfish oil to reach the Codex 2017 standard.