Quality of western Canadian flaxseed 2012
Fatty acid composition
The average α-linolenic acid content of 2012 harvest survey Flaxseed, No. 1 CW samples is 56.8%, lower than 2011 at 57.6% and similar to the 10-year mean (Figure 5). Compared to 2011, the average α-linolenic acid content decreased by 1.4%, 0.5 and 1.8 %for Manitoba, Saskatchewan and Alberta respectively. Flaxseed, No. 1 CW samples from producers across western Canada had a range of linolenic acid content from 50.0% to 65.8%.
The average iodine value of the oil from Flaxseed, No. 1 CW samples is 190.7 units. Iodine value is a measure of the total degree of unsaturation of the oil and in flaxseed is heavily influenced by the linolenic acid content of the oil. The 2012 iodine value is 1.8 units lower than in 2011 and .60 units lower than the 10-year mean of 191.3 units (Figure 6). The average iodine value decreased by 3 units, 1 unit, and 3.3 units for Manitoba Saskatchewan and Alberta samples, when compared to 2011. Flaxseed, No. 1 CW samples from producers across western Canada varied in iodine value from 179.6 to 205.2 units.
Usually oils with iodine values greater than 188 units are desired by the coatings industry for products such as paints, varnishes and inks, while oils with iodine values around 183 units are preferred by the linoleum industry. Iodine value, like oil content, is influenced by growing temperatures and length of photoperiod.
The 2011–2012 mean export values in Table 6 shows the α-linolenic acid content at 57.6% and the iodine value at 192.8 units. Flaxseed, No. 1 CW exports will likely produce oils with iodine values around 190 units. Flaxseed exports that are not commercially clean may have lower iodine values than those exports that are cleaned to contain less than 2.5% dockage.
Figure 5. Flaxseed, No. 1 Canada Western, Percent α-linolenic acid content of harvest survey samples, 2002–2012
The table below displays the percentage α-linolenic acid content from 2002 to 2012 which is illustrated in the graph.
|Crop year||α-linolenic acid content, %|
Figure 6. Flaxseed, No. 1 Canada Western, Iodine value of harvest survey samples, 2002–2012
The table below displays the percentage iodine value from 2002 to 2012 which is illustrated in the graph.
|Crop year||Iodine value, Units|