Fatty acids and sterols in oils from canola screenings

Abstract

One sample of canola seed (variety Tower) and five samples of screenings were commercially processed to yield first an “expeller oil” and subsequently an “extractor oil” by the hexane extraction of the residue. The screening samples contained 25–50% intact or broken canola seed. The balance included 21–31% weed seeds (especially lambsquarter and stinkweed), hulls, fragments of the embryo, and chaff. All the oil samples were analyzed for sterol and fatty acid composition. The extractor screening samples had slightly higher sterol contents than the corresponding expeller samples, while the Tower samples gave the lowest values. The averages (in mg/g oil or extract) for the extractor screening samples were: brassicasterol, 1.0; campesterol, 4.1; and β‐sitosterol, 7.3. For expeller screening samples the average were: 0.9, 3.6 and 6.2 and for the Tower oils they were, respectively, 0.9, 3.8, 5.3 and 0.9, 3.5, 4.7. The fatty acid compositions of the screening samples for both extractor and expeller oils were similar to that of the Tower oil except for the higher proportions of docosenoic acid (22:1) and eicosenoic acid (20:1) and the more obvious presence of three C18 conjugated dienes totalling up to 0.6% of one screening oil sample. The docosenoic acid level (mainly erucic acid) ranged from 3.0 to 7.0% for the extractor oils and from 2.5 to 8.0% for the expeller samples, compared to 0.1% for the two Tower oils. The oil contents of the screenings ranged from 20 to 30%, and the fatty acids and sterols appear to be nutritionally useful and innocuous in all respects.

Canola Fatty Acids—An Ideal Mixture for Health, Nutrition, and Food Use

“…Some are artifacts of peroxide destruction during refining, and some are present naturally in seed oils, probably for similar reasons. They may be confused with 20:0 or 20: 1 in polar column GLC analyses Ackman and Sebedio 1981). The refining process itself is a source of artifact fatty acids due to isomerization of one or more of the bonds of all-Gis-linolenic acid (9, 12,15-octadecatrienoic acid) to the corresponding trans-geometry (Ackman et al 1974;Grandgirard et al 1984).…”

Canola and Rapeseed

“…Some are artifacts of peroxide destruction during refining, and some are present naturally in seed oils, probably for similar reasons. They may be confused with 20:0 or 20: 1 in polar column GLC analyses Ackman and Sebedio 1981 The refining process itself is a source of artifact fatty acids due to isomerization of one or more of the bonds of all-Gis-linolenic acid (9, 12,15-octadecatrienoic acid) to the corresponding trans-geometry (Ackman et al 1974;Grandgirard et al 1984). Figure 6-3 shows a part of the gas-liquid chromatograms of a LEAR oil before and after steam deodorization (Ackman et al 1974).…”

Determination of selenium, arsenic, iodine and bromine in fish, plant and mammalian oils by cyclic instrumental neutron activation analysis

“…The LEAR (low erucic acid) or canola oils (cv. Tower) included two commercial lots which were also solvent-extracted, and one lot of oil expelled mechanically on a small scale without solvent at the POS Pilot Plant Corporation, Saskatoon (12,13). The crude soybean oil came from commercially solvent-extracted seed.…”