Fish Liver Lipid Extraction And Composition Analysis

Skate is byproduct of tuna in ocean purse seines.The number of skate byproduct islarge, the proportion of processing scraps exceeds50%, and liver accounts for more than10%of scraps; the head of Lophius litulon is big with the small body. The visceralaccounts for more than60%of scraps, and the liver accounts for11%of scraps. Both aregood raw material of fish oil. At this stage, the lipid composition is not clear and due to therestrictions of technical level. At domestic enterprises, their use is still blank. Firstly, theimpact of the different extraction methods on the rate of fish liver oil extraction, sensoryand physicochemical properties was researched. The results showed that the extraction rateof the alkaline protease was highest, and the quality of cod liver oil was best.The optimum extraction parameters of alkaline protease was studyed by orthogonalexperiment. The results showed that the optimum extraction parameters: initial pH8, liquidto solid ratio1:1, the enzymatic temperature45℃, the enzymatic time3.5h,2.0%of theamount of enzyme, and the cod liver oil extraction rate of Lophius litulonl and skate underthe conditions were86.46%and88.63%respectively, They were lighter reddish brownwith cod liver oil smell slightly, and the sensory and physical and chemical indicators werein line with the two requirements of coarse fish oil standards of SC/T3502-2000.Then, squalene and alkoxy glycerol in unsaponifiable matter of cod liver oil wereanalyzed by the thin layer chromatography, and the content of EPA, DHA in cod liver oilwere analyzed by gas chromatography. The results showed that the cod liver oil of skateand Lophius litulon both contained certain protractor squalene and alkoxy glycerol, thecontent of EPA and DHA in former were2.507%and20.851%respectively, and thecontent of EPA and DHA in latter were3.949%and12.495%respectively. Finally, through the refining process, the refining process parameters of skate codliver oil was determined:with800g/L H3PO4solution to degumming,its adding amount1%of the oi weightl; with300g/L NaOH solution to deacidification, its adding amount was2%of the oil weight; with activated clay to bleaching, its adding amount is6%of the oilweight; the deodorization was10min under85℃reduced pressure distillation. therefining process parameters of Lophius litulon cod liver oil:with800g/L H3PO4solution todegumming, its adding amount1%of the oil weight; with300g/L NaOH solution todeacidification, its adding amount was2%of the oil weight; with activated clay tobleaching, its adding amount was8%of the oil weight; the deodorization was10minunder85℃reduced pressure distillation. After refining, the former became pale yellow,the latter became pale red, and both were clear and transparent with pale fish smell, theirphysical and chemical indicators meeted the one requirement of refined fish oil standard ofSC/T3502-2000.