A comparison of the effects of various purification treatments on the oxidative stability of squid visceral oil

Abstract

Factors influencing the oxidative stability of refined squid visceral oil after various purification treatments were evaluated. Squid visceral oil was treated by refining, steam deodorizing, molecular distillation, Sep‐Pak cartridge extraction, alumina adsorption, EDTA solution washing, and column chromatography, and the treated oils were compared for oxidative stability. Sep‐Pak cartridge extraction and alumina adsorption were designed to eliminate phenolic compounds, α‐tocopherol, phospholipids, and metal ions from the oil. The oxidative stability was measured using PV and increase in weight. The refined oil and the deodorized oil were the most stable, and the highly purified oil was the least stable. However, alumina‐adsorbed oil that had been washed with EDTA was more resistant to oxidation than highly purified oil. When refined oil was passed through an activated carbon‐Celite chromatography column, it could be separated into hexane, ether, and ethanol fractions. The ethanol eluate contained more α‐tocopherol and phospholipids than the ether eluate. The addition of the ethanol eluate extracted from squid visceral oil to the highly purified oil resulted in excellent stability.

Squid Oil and Fat Production from Squid Wastes Using Subcritical Water Hydrolysis: Free Fatty Acids and Transesterification

“…The fatty acid methyl esters of the fat phase under methylation reaction show similar types of peaks to the oil phase (Figure b). These products matched those obtained in crude squid oil and, also, the results of some studies on the fatty acids content in squid tissue oil. −

2 GC−MS chromatograph of the typical free fatty acids in the oil phase and methyl ester fatty acids in the fat phase at 493 K and 10 min.

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“…These products matched those obtained in crude squid oil and, also, the results of some studies on the fatty acids content in squid tissue oil. [35][36] Figure 3 shows the reaction temperature effect on the amount of the oil and fat phases and the yield of glycerol in the aqueous phase after sub-CW reaction. The pressure changes under reaction conditions were shown in the range of 0.792 (443 K) to 30 MPa (653 K).…”

Optimization of α-tocopherol and ascorbyl palmitate addition for the stabilization of sardine oil

“…However, the peroxide value was maintained practically constant at around 2.7 meq O 2 ·Kg −1 oil. Although it was reported that adsorption on silica-alumina reduces hydroperoxides in the oil, this high-purity oil also showed rapid oxidation (Lin and Hwang, 2002). Thus, it is suggested that a reduction in PV could have happened but the oil matrix may have suffered oxidation after the purification process.…”

“…The fish oil matrix was obtained from crude sardine oil by chromatographic purification on an alumina-silica column according to the method described by Lin and Hwang (2002) with some modifications. A glass chromatographic column (5×50 cm) was packed with 100 g of silica gel (70-230 mesh, Merck) and 100 g of basic alumina (70-230 mesh, Merck) suspended in hexane (400 mL).…”