Health Canada has notified DuPont Canada Inc. that is has no objection to the food use of high oleic soybean lines G94-1, G94-19, and G168, which have been developed to produce oil with elevated levels of oleic acid. The Department conducted a comprehensive assessment of these soybean lines according to the Guidelines for the Safety Assessment of Novel Foods. These Guidelines are based upon internationally accepted principles for establishing the safety of foods with novel traits.
The following provides a summary regarding the DuPont notification to Health Canada and contains no confidential business information.
DuPont Agricultural Products has developed a transgenic soybean line which produces an oil with levels of oleic acid exceeding 80%, versus 23 % found in a typical conventional soybean oil. This soybean line, called high oleic soybeans, is homozygous for a GmFad 2-1 cDNA in the sense orientation under the control of a seed-specific promoter. The inserted GmFad 2-1 cDNA is causing a co-ordinate silencing of itself and the endogenous GmFad 2-1 gene.
In developing soybeans, the second double bond is added to oleic acid in the d-12 (omega-6) position by a d-12 desaturase, encoded by the GmFad 2-1 gene. A second Fad 2 gene (GmFad 2-2) is expressed in all tissues of the soybean plant. Silencing of the GmFad 2-1 in developing soybeans suppresses the addition of a second double bond to oleic acid, resulting in greatly increased oleic acid levels in the seed only.
The result is a more heat stable soybean oil which may be used in food applications such as frying without the need for chemical hydrogenation which converts polyunsaturated fatty acids like linolenic and linoleic acids to either trans or saturated fatty acids.
The two trait genes that were introduced into the Asgrow Seed Company elite soybean line A2396 by particle bombardment are GmFad2-1, which affects the fatty acid composition, and dapA, which increases the lysine levels. Both the GmFad 2-1 and dapA genes are under the control of a seed storage promoter and are only active in the seeds. In addition, beta-lactamase (bla) and beta-glucuronidase (GUS) were used as selectable markers. The original R0 plant (event 260-05) contained inserts at three loci; A, B, and C. At locus A, two copies of the GmFad 2-1 gene were causing a suppression of the endogenous GmFad 2-1 gene resulting in an oleic content of greater than 80%. Sublines G94-1, G94-19, and G168 were selected which contained locus A, but had lost the active dapA gene (high lysine trait) at locus B via segregation. A truncated dapA gene at locus C was non-functional since it lacks the genetic elements necessary for protein expression and a marker gene coding for beta-lactamase was not expressed since it is under the control of a bacterial promoter. The expression of the selectable marker beta-glucuronidase used to select original transformant, line 260-05, was below the limits of detection when the high oleic soybean sublines were assayed. Thus, in all of the selected sublines of high oleic soybeans, no new proteins are present.
Growth and genetic stability of the high oleic soybean sublines were determined in multi-year field tests over eight generations in a variety of locations and growing seasons.
Compositionally, high oleic soybeans did not differ significantly from control soybeans in levels of total protein, oil, carbohydrate, crude fiber, ash, individual amino acids, minerals, vitamins, trypsin inhibitor, phytic acid, the oligosaccharides raffinose and stachyose, daidzein, genistein or glycitein. High oleic soybean oil contains oleic acid levels exceeding 80 %, which is higher than those found in olive oil and rapeseed oil, along with low levels of the polyunsaturated fatty acid linoleic acid at 2 % and significantly lower levels of linolenic acid. Levels of saturated fatty acids are considerably lower than those found in regular soybean oil, and approaching those of canola oil. Trace amounts (0.5 %) of a linoleic acid isomer were also detected, which while absent from non-hydrogenated soybean oil, is present at similar levels in butterfat, and is often found at considerably higher levels in partially hydrogenated vegetable oils (1-3%). For comparison, regular soybean oil contains, on average, approximately 23% oleic acid, 51% linoleic acid, 6.8 % linolenic acid, and 14.4 % saturated fatty acids.
The high oleic soybean lines are expected to be used in applications similar to traditional soybean varieties by the food industry. High oleic soybean oil would fit best into food applications where a highly stable oil is required, such as in frying operations.
As noted above, the compositional analyses, including proximates, amino acids, fatty acids, and anti-nutritional factors as well as vitamins, including tocopherol, minerals, and isoflavones in High Oleic Soybeans revealed no nutritionally significant differences compared to typical commercial soybeans, except for the fatty acid profile.
Oil derived from high oleic soybean lines will be listed in food ingredient lists by the common name, "high oleic soybean oil", to distinguish it from regular soybean oil. Because of the major change in fatty acid profile, the high oleic soybean oil cannot be directly substituted for regular soybean oil in products requiring a specific fatty acid composition without adjustments to the amounts and types of other fat ingredients to achieve the desired profile.
No new proteins are expressed in high oleic soybeans. In addition, high oleic soybeans were found to have no significant differences in endogenous antinutrients (phytic acid, trypsin inhibitor, raffinose, stacchyose) and isoflavones in comparison with traditional soybean varieties within ranges of natural variation.
Data demonstrates that there are no significant differences between the high oleic soybean lines and non-modified soybeans with regard to their endogenous allergen content. There are no novel protein expressed in the high oleic soybean lines. Therefore, there are no allergenicity concerns associated with the high oleic soybean lines.
Health Canada's review of the information presented in support of the food use of high oleic soybean lines G94-1, G94-19, and G168, concluded that these lines do not present human food safety concerns. Health Canada is of the opinion that products from these soybean lines are as safe as those made from currently available commercial soybean varieties. The change in fatty acid profile creates an oil with significantly different nutritional value which must be taken into account in applications where a specific fatty acid composition is desired or required.
Health Canada's opinion pertains only to the food use of high oleic soybean lines G94-1, G94-19, and G168. Issues related to growing these soybean lines in Canada and their use as an animal feed are addressed separately through existing regulatory processes in the Canadian Food Inspection Agency.
This Novel Food Information document has been prepared to summarize the opinion regarding the subject product provided by the Food Directorate, Health Products and Food Branch, Health Canada. This opinion is based upon the comprehensive review of information submitted by the petitioner according to the Guidelines for the Safety Assessment of Novel Foods.
(╔galement disponible en franšais)
For further information, please contact:
Office of Food Biotechnology
Health Products and Food Branch
Ottawa, Ontario K1A 0L2
Telephone: (613) 941-5535
Facsimile: (613) 952-6400