Quality of Canadian Soybean, oilseed-type 2018

5. Fatty acid composition

Table 4 shows fatty acid composition for the combined No. 1 and 2 grade composites from the various provinces. Linolenic acid (C18:2), the main fatty acid found in soybean oil, averaged 53.6% and ranged from 50.1 to 58.4%, whereas last years average was 54.4% with a range from 52.5% to 55.7%. Oleic acid, the second most important soybean fatty acid, averaged 21.8% in 2018, much higher than the 2017 value of 20.0%. The other important unsaturated fatty acid, ɑ-linolenic acid (C18:3), averaged 8.3% (9.6% in 2017) and ranged from 8.7% to 10.4%. Total saturates averaged 15.6% in Canada varying from 14.8% (Maritimes) to 15.7% (Manitoba).

Iodine value estimates the level of fatty acid unsaturation in oil; the higher the number of double bonds in the oil the higher the iodine value and the level of unsaturation. For 2018, both ɑ-linolenic acid and linoleic acid averages were lower than last year; this is reflected by the 2018 iodine value average being much lower than last year average, 133.5 units in 2018 versus 137.0 units in 2017. Figure 7 presents the iodine value trend since 2006 for eastern Canada and western Canada and the overall Canadian averages. The yearly variations are a reflection of the environmental differences that includes geography (temperature and precipitation being different between eastern and western Canada).

There is no requirement to control the fatty acid composition of the Canadian oilseed-type soybeans, therefore variety can show large variation in the fatty acid composition. These variations are amplified as weather also plays a part in year-to-year fatty composition changes, in hot and dry weather conditions, seeds tend to produce an oil with more saturation, e.g. less polyunsaturated fatty acids such as linolenic and linoleic acids and more total saturates and oleic acid. The opposite will be observed if seeds are grown in cool conditions.

Figure 7. Iodine value averages of Canadian oilseed type soybean, 2006 to 2018

Iodine value averages of Canadian oilseed type soybean,2006-18.
  • Details
    Iodine value averages of Canadian oilseed type soybean, 2006 to 2018
    Region 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
    Western Canada 132.9 137.6 138.1 137.8 139.2 132.4 131.2 134.0 140.0 134.5 136.4 134.7 134.6
    Eastern Canada 138.6 132.8 135.0 137.0 133.6 136.1 132.4 134.2 136.5 133.3 132.0 138.0 -
    Canada 137.7 133.6 135.7 137.2 135.4 134.6 132.1 134.1 137.5 133.7 133.2 137.0 134.6
Main fatty acid contents and iodine value of the oil of the 2018 soybean survey by province and grade
Province Number of samples %, in oil SATSFootnote 1 Iodine Value, UnitsFootnote 2
C16:0 C18:0 C18:1 C18:2 C18:3
Soybean, No. 1 Canada and Soybean No. 2 Canada
Manitoba 110 10.8 4.6 23.2 52.2 8.1 15.7 131.9
Saskatchewan 28 10.6 4.2 20.8 54.2 9.0 15.2 135.6
Alberta 1 10.1 4.7 21.2 53.8 8.6 15.7 134.1
Western Canada 139 10.7 4.6 22.9 52.5 8.2 15.7 132.4
Ontario 153 11.8 3.9 21.5 53.8 8.3 15.6 133.6
Québec 30 10.7 3.8 21.2 54.4 8.2 15.4 134.3
Central Canada 183 10.9 3.9 21.5 53.9 8.3 15.6 133.7
Prince Edward Island 4 14.2 3.7 19.6 55.4 9.5 14.8 137.9
New Brunswick 3 12.2 3.9 23.5 52.6 8.3 14.7 133.4
Nova Scotia NAFootnote 4 - - - - - - -
Maritimes 7 10.1 3.8 19.6 55.4 9.5 14.8 137.9
Canada 329 10.7 4.0 21.8 53.6 8.3 15.6 133.5
Soybean, No. 3
Western Canada 26 9.8 5.0 24.4 51.4 7.5 15.9 129.9
Eastern CanadaFootnote 3 6 10.6 3.7 21.2 54.7 8.2 15.0 134.7
Canada 32 10.0 4.7 23.8 52.0 7.6 15.8 130.8
Soybean, No. 4
Western Canada 13 10.0 4.5 21.5 53.7 8.6 15.4 134.3
Eastern Canada NA - - - - - - -
Canada 13 10.0 4.5 21.5 53.7 8.6 15.4 134.3
Soybean, No. 5
Western Canada 16 9.9 4.8 23.5 51.9 8.0 15.8 131.4
Eastern Canada NA - - - - - - -
Canada 16 9.9 4.8 23.5 51.9 8.0 15.8 131.4
Soybean, Sample
Western Canada 12 9.8 4.5 21.5 53.5 8.9 15.3 134.6
Eastern Canada NA - - - - - - -
Canada 12 9.8 4.5 21.5 53.5 8.9 15.3 134.6