Quality of Tuna Fish Oils Extracted from Processing the By-Products of Three Species of Neritic Tuna Using Supercritical Carbon Dioxide

Abstract

Fatty acid constituents of total lipids extracted from the head, the skin and the viscera of three neritic tuna species, namely Thunnus tonggol, Euthynnus affinis and Auxis thazard, using supercritical carbon dioxide (SC-CO2) and Soxhlet extraction method were determined and compared. Saturated fatty acid (39.7-48.5%) was dominant in conjunction with monounsaturated fatty acid (21.9-26.6%) and polyunsaturated fatty acid (PUFA) (24.1-27.9%) in all species, and the difference between methods were nonsignificant. Docosahexaenoic acid was the major PUFA, accounting for 17.0-19.9% in the head, 15.7-17.3% in the skin and 14.3-16.1% in the viscera of total fatty acids. Total oil extracted by SC-CO2 had lower free fatty acid (FFA) and peroxide value (PV) content than that by Soxhlet method. The ranges of FFA and PV were 1.8-5.0 and 1.2-2.4%, respectively. It was concluded that SC-CO2 is an effective method to extract fish oil that is rich in omega-3 fatty acids from tuna by-products.

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“…The yield of extracted oil may vary between traditional solvent extraction methods and SE. Ferdosh et al (2015) extracted 26.4% and 24.8% oil using HE and SE, respectively, from the skins of tuna (Euthynnus affinis), which was similar to the current results. Fish oil (11.7% from wet weight) was produced commercially from anchovy (Ceyhan & Emir, 2015).…”

“…The yield using SE has been reported to depend on temperature, pressure, type of sample, size of sample and moisture content in the sample (Rubio-Rodriguez et al, 2008;2012). The higher extraction yield using HE might be due to extraction at high temperature for a longer period of time, which facilitates having some protein and other compounds in the extracted oil (Ferdosh et al, 2015). In SC-CO2 oil extraction patterns (Fig 2), oil extraction rate was higher at initial stage that was decreased gradually with the time elapse.…”

“…The tuna by-products contained considerable amount of EPA+DHA, 28.3% in scales, 27.8% in skins and 26.7% in bones. Ferdosh et al (2015) reported 17.9-19.0% EPA+DHA in skins oil of three kinds of tuna. The difference might be due to the type of tuna, location of harvesting area and differences in extraction conditions.…”

“…Oil was extracted using the method of Ferdosh et al (2015) with slight modifications. About 5 g of freeze-dried ground skins (or 15 g of bones or scales) were put into a thimble and extracted with 100 ml nhexane (97.8% purity, SK Chemicals, Gyeonggi-do, Korea) in a Soxhlet apparatus (64825 Supelco, Sigma Aldrich, St. Louis, MO, USA).…”

Effect of Microwave Pretreatment on Extraction Yield and Quality of Catfish Oil in Northern Thailand

“…Fish oil was usually obtained by various extraction techniques [4]. Several studied on methods and conditions for fish oil extraction have been conducted in the past including solvent extraction method [5,] supercritical fluid extraction [6], soxhlet method [7], wet and steam rendering methods [8] and wet pressing method [9]. Among these techniques, wet pressing method is widely used for oil extraction in the industrial scale as described by Food and Agriculture Organization [9].…”