Supercritical carbon dioxide extraction of Gac oil

1. IntroductionGac (Momordica cochinchinensis Spreng) is one of traditionalfruits grown in Southeast Asia, particularly in Vietnam [1]. Gac arilcontains high amount of carotenoids (891.50 g g−1fresh weight)mainly in the form of -carotene and lycopene [2]. It is also reportedthat Gac aril has about 10 times the -carotene of a carrot [3].Carotenoids are interesting valuable minor components. Thepresence of carotenoids plays an important role in oxidative protec-tion. Many studies have also reported that carotenoids can providesupport for prevention and control of diseases caused by vitaminA deficiency [4,5]. Therefore carotenoid-rich Gac fruit has recentlybeen attracting attentions of many researches [6–10].Recovery of oil and carotenoids from Gac aril by mechani-cal pressing is the most commonly used method [3]. Recently,supercritical fluid technology has been proven to be a modern sep-aration technique applied in edible oil processing. Carbon dioxideis a suitable solvent because of its moderate critical pressure andtemperature. Moreover carbon dioxide is a non-toxic, inexpensiveand environmentally friendly solvent. Supercritical carbon dioxide(SC-CO2) can be used to extract various solutes from feed matrixbecause of its special solvent behaviour which can be changedwith pressure and temperature applied [11]. Extractions of highcarotenoid materials by SC-CO2have been conducted with palmmesocarp [12], crude palm oil [13,14], buriti [15] and tomato[16,17].

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