In the mid-1980’s the US regulations allowed for the declaration of saturates as a per cent of total fatty acids and only those saturates from fatty acids with carbon chain lengths of 18 or less were included. At that time the claim made on most brands of canola oil was 6% saturates. Since the percentage was rounded to the nearest whole per cent, this required the saturates in any sample of canola oil to be no more than 6.49%.

As a result of changes culminating in the "Nutrition Labeling and Education Act" of 1990, requirements for the declaration of fat and saturated fat in foods sold in the US changed significantly. This is particularly important since nutrition labeling is now mandatory. One important change is that saturated fat is now required to include all saturated fatty acids regardless of chain length. This has resulted in the per cent saturates in canola oil going from about 6% if fatty acids with chain lengths of C18 and less are included to about 7.5%. Another change is that saturates or other fatty acids are no longer declared as a per cent of total fat or as grams per 100 grams of a food item, but rather are declared in grams per reference serving size. In the case of salad oil, the reference serving size is 14 grams. If the level of saturated fat in a serving is less than 5 grams then it must be declared to the nearest 0.5 grams. For a serving of salad oil, 1 gram of saturates would be about 7.1% and 1.5 grams would be 10.7%. Canola salad oil is declared as 1 gram of saturates per serving. In order to make that declaration, it can never exceed 8.9% (1.25 grams) in a packaged oil product.

The saturates standard for approving a new canola variety is based on the level that is found in seed grown in the "co-op trials". Since it is known that environmental factors will affect this level in a given growing season or a given geographical area and since it is also known that the variability will increase once it gets to commercial production, it was decided that a 7% maximum should be set on new canola varieties being presented for registration. This provides some margin of safety to ensure that packaged canola oil will always meet the US requirements for declaring one gram of saturates per serving.

Currently the Canadian varietal recommending group considers only even chain saturated fatty acids from C16:0 to C22:0 inclusive. This report will consider total saturated fatty acids as the sum of even chain fatty acids from C14:0 to C24:0 inclusive, measured as percentage of the total fatty acids found in the sample.

Canadian canola is made up of seed and oil from two species, Brassica napus L. and Brassica rapa L. Although B. rapa varieties are somewhat lower in yield than B. napus varieties they have a

Figure 1. Proportion of B. napus Varieties in Western Canadian Production. Source: 1976-1988, Prairie Grains Variety Survey (Praire Pools Inc.), 1989-1997, Canadian Grain Commission.

shorter growing period and are more suited to the northern growing area in Western Canada. No effort is made to segregate the two species in either the bulk handling system or on entry to processing facilities so that commercial samples of Canadian canola seed, meal or oil is may contain various proportions of either species. Between 1976 and 1992, the proportion of B. napus in the crop ranged from 45% to 60%. In recent years, agronomic advantages of B. napus varieties (disease resistance, herbicide tolerance, yield advantage) have led to an increase in the proportion of B. napus grown in Western Canada (Figure 1).

The fatty acid composition of the oil from these two species differs considerably (Table 1) with B. rapa having lower levels of saturated fatty acids and monoenes and higher levels of dienes and trienes than B. napus.

Figure 2. Level of saturated fatty acids and proportion of B. napus in Canadian canola. Data from Canadian Grain Commission.

Harvest surveys of Canadian canola 4 have shown increased levels of saturated fatty acids in recent years (Figure 2). No significant increase was noted in the saturated fatty acids from either B. napus or B. rapa varieties derived from these surveys. The saturated fatty acid level of B. rapa varieties actually appeared to decrease, possibly due to a greater proportion of these being grown in northern areas. These findings suggest that the the increase in proportion of B. napus grown is a major influence in the increase in saturated fatty acids.

Further evidence of this effect can be seen by the relationship between saturated fatty acids and the amount of B. rapa found in composite samples representing individual crop districts from harvest

Figure 3. Relationship between saturated fatty acids and proportion of B.  rapa in crop district composites for harvest surveys from 1985 to 1997.

surveys (Figure 3). Other factors which may cause changes in the saturated fatty acid content ofcanola include environment and variety. Environmental effects include growing location where cooler areas (north and west) might be expected to result in decreased saturation. Regression analysis including other factors such as year and location (latitude and longitude of the center of the crop district) resulted in an increase in R2 from -0.66 to -0.78. While this increase is significant and may represent real effects, it should be remembered that the amount of B. napus grown also varies significantly with these parameters.

The level in saturated fatty acids in Canadian canola varies across the prairies (Table 2). Lower levels of saturated fatty acids are found in more western (Alberta) and northern (higher numbered crop districts) areas. It is also these areas where the greatest proportion of B. rapa is grown.

Studies on frost damaged canola showed that severely damaged samples had higher levels of saturated fatty acids ⁵. This suggests that lower grade canola might have higher levels of saturated fatty acids. Inspection of data from harvest surveys from 1985 to 1997 showed that, when data was corrected for the proportion of each species present, there was no statistical difference between No. 1 Canada canola and No. 2 Canada canola.

Decreases in the level of saturated fatty acids in canola may be achieved through development of varieties low in saturated fatty acids. The canola varietal recommending group has made that a priority and has set goals for action. Examination of the saturated fatty acids in varieties in harvest surveys from 1995 to 1997 shows only a limited range of saturated fatty acids (Table 3). The hybrid variety Hyola 401 was the highest while the variety 46A65 was lowest. These two lines appear to differ by about 0.5% saturated fatty acids.

The data from Table 3 also indicates that there is a large environmental component to be dealt with when selecting for saturated fatty acids. A further complication is analytical variation. Analysis of saturated fatty acids by gas chromatography requires summation of up to 5 different fatty acids, ranging in amount from less than 0.1% to about 6%. This results in a considerable degree of error in the method. The Grain Research Laboratory reports a long term standard deviation of less than 0.1% for total saturated fatty acids in their analytical quality control program. Results between laboratories may be more variable. While most laboratories participating in a check sample program for canola had within laboratory standard deviations in the order of 0.1%, between laboratory standard deviations were between 0.2 and 0.3%.

In conclusion, increases in saturated fatty acids in Western Canadian canola, especially over the past three years, seem to be mainly due to the increase in the proportion of B. napus varieties grown. Saturated fatty acids were found to be lower in the more northern and western parts of the canola growing area. In B. napus varieties currently grown, there seems to be a range of about 0.5% saturated fatty acid, suggesting that it should be possible to achieve a significant reduction in this parameter through conventional breeding techniques.

Acknowledgements:

Mr. Jim Dyck, CanAmera Foods Ltd., Saskatoon, SK provided information on the labelling requirements for saturated fatty acids. Mr. Barry Misener of the Canadian Grain Commission carried out analysis of fatty acid composition.

Reference List

1. McDonald B.E. Canola Oil Nutritional Properties . Winnipeg: Canola Council of Canada; 1990.

2. Dupont J., White P.J., Johnstonk K.M., Heggtveit H.A., McDonald B.E., Grundy S.M., Bonanome A. Food safety and health effects of canola oil. J. Am. Coll. Nutr. 1989;8:360-75.

3. Daun J.K. Modified Fatty Acid Profiles in Canadian Oilseeds. J. Japan. Oil Chem Soc. 1998;17(3).

4. DeClercq D.R., Daun J.K., Tipples K.H. Quality of Western Canadian Canola 1997 . Winnipeg: Canadian Grain Commission; 1997.*

5. Daun J.K., Clear K.M., Mills J.T. Effect of Frost Damage on the Quality of Canola B. napus. J. Amer. Oil Chem. Soc. 1985;62(4):715-9.

*Note: Quality of Western Canadian Canola 1997 and 1998 are available on this Website.