Wax composition of sunflower seed oils

Abstract

Waxes are natural components of sunflower oils, consisting mainly of esters of FA with fatty alcohols, that are partially removed in the winterization process during oil refining. The wax composition of sunflower seed as well as the influence of processing on the oil wax concentration was studied using capillary GLC. Sunflower oils obtained by solvent extraction from whole seed, dehulled seed, and seed hulls were analyzed and compared with commercial crude and refined oils. The main components of crude sunflower oil waxes were esters having carbon atom numbers between 36 and 48, with a high concentration in the C 40 -C 42 fraction. Extracted oils showed higher concentrations of waxes than those obtained by pressing, especially in the higher M.W. fraction, but the wax content was not affected significantly by water degumming. The hull contribution to the sunflower oil wax content was higher than 40 wt%, resulting in 75 wt % in the crystallized fraction. The oil wax content could be reduced appreciably by hexane washing or partial dehulling of the seed. Waxes in dewaxed and refined sunflower oils were mainly constituted by esters containing fewer than 42 carbon atoms, indicating that these were mostly soluble and remained in the oil after processing.

Chemical characterization of oils and meals from wild sunflower (helianthus petiolaris nutt)

“…Wax composition was determined by separation with a silica gel chromatographic column and analysis by GC. A Varian 3700 GLC with FID detector and on-column injection (Varian Associates Inc.), an HP5, 11 m × 0.32 mm (0.52 µm) capillary column (Hewlett-Packard, Palo Alto, CA), and a Millenium 2010 data processor (Millipore Corporation, Milford, MA) were used (10). Separation of polar compounds was carried out by column chromatography with silica gel and verified by TLC according to AOCS method Cd 20-91 (8).…”

Effects of refining process on sunflower oil minor components: a review

“…Sunflower seeds contain around 0.9% of waxes (Carelli et al, 2002) that are present in the hulls. Only a part of the total wax content is eliminated during the winterization step of the refining process, only the small wax chains with less than D207, page 3 of 10 42 carbons are found in the final product (Carelli et al, 2002).…”

“…Only a part of the total wax content is eliminated during the winterization step of the refining process, only the small wax chains with less than D207, page 3 of 10 42 carbons are found in the final product (Carelli et al, 2002). Sunflower has mainly C40 and C41 waxes in cold pressed oil (26.8 and 30.2 mg/kg) for a total of 205 mg/kg, whereas in pressed oil C44 was the most abundant (20.3 mg/kg) followed by C41, C46 and C40 for a total of 409 mg/kg (Brevedan et al, 2000), in both cases oil has a wax diversity from C36 to C48.…”

“…In addition, the degumming step could be done using enzymatic treatment (Carelli et al, 2002;Lamas et al, 2014). Phospholipid content is reduced up to 97.8% while phosphorus content is decreased up 99.4% (Lamas et al, 2014).…”

Green waxes, adhesives and lubricants

“…For example, castor wax is produced by the hydrogenation of pure castor oil with nickel catalyst (Zajcew 1958); partially hydrogenated soybean oil gives soy wax (Frankel et al 1967); alcoholysized palm oil gives palm wax (Hassan et al 2004); and jojoba wax is prepared by the hydrogenation or interesterification of jojoba oil (Miwa 1972). Some vegetable oils, such as sunflower oil (Carelli et al 2002), canola oil (Hu et al 1993) and rice bran oil (Mezouari et al 2006), contain waxes that are undesirable in the edible oil and are therefore removed during the purification process.…”