Novel food information: Enhanced stearate soybean

On this page:

• Background
• Introduction
• Development of the modified plant
• Characterization of the modified plant
• Product information
• Dietary exposure
• Nutrition
• Toxicology
• Conclusion

Background

Health Canada has notified Monsanto Canada Inc. that it has no objection to the sale of food derived from Enhanced Stearate Soybean (ESS) soybean varieties conventionally bred from line HS-2. The Department conducted a comprehensive assessment of this soybean event according to its Guidelines for the Safety Assessment of Novel Foods (September 1994). These Guidelines are based upon internationally accepted principles for establishing the safety of foods with novel traits.

The following provides a summary of the notification from Monsanto Canada Inc. and the evaluation of the information performed by Heath Canada. This document contains no confidential business information.

Introduction

Monsanto has developed ESS varieties conventionally bred from soybean line HS-2 with increased levels of stearic acid, and reduced levels of linolenic acid. Stearic acid is a saturated fatty acid that is solid at room temperature. Linolenic acid is a polyunsaturated fatty acid that is subject to oxidation, which is responsible for the off-flavours associated with rancid oil. Taken together, the modified fatty acid profile of oil from ESS varieties will impart desirable physical properties that are useful in various food applications, such as the production of shortening and margarine, bakery products, and in frying applications. Thus, oil from ESS varieties can be a suitable alternative in food applications where tropical oils and/or partially hydrogenated vegetable oils are used.

The safety assessment performed by Food Directorate evaluators was conducted according to Health Canada's Guidelines for the Safety Assessment of Novel Foods. The assessment considered: how ESS varieties conventionally bred from soybean line HS-2 are developed; how the composition and nutritional quality of soybean seed derived from ESS varieties compare to regular commodity soybean; and what the potential is for food products derived from ESS varieties to be toxic or cause allergic reactions.

The Food Directorate has a legislated responsibility for pre-market assessment of novel foods and novel food ingredients as detailed in Division 28 of Part B of the Food and Drug Regulations (Novel Foods). Foods derived from ESS varieties conventionally bred from soybean line HS-2 are considered novel under the following part of the definition of novel foods: "c) a food that is derived from a plant, animal or microorganism that has been genetically modified such that

1. one or more characteristics of the plant, animal or microorganism no longer fall within the anticipated range for that plant, animal or microorganism."

Development of the modified plant

ESS varieties are conventionally bred from soybean line HS-2. The high stearic acid trait in HS-2 is derived from parental breeding line A6. The low linolenic acid phenotype in HS-2 is mainly contributed by the parental breeding line PI 123440.

The mutant line A6 was derived by sodium azide treatment. Chemical mutagenesis resulted in a deletion in the Delta9c gene encoding delta-9 stearoyl-acyl carrier protein desaturase (SACPD). The SACPD enzyme normally inserts a double bond at the delta 9 (omega 9) position of stearic acid to form oleic acid. The mutant allele for the above enzyme results in the accumulation of stearic acid levels in seed and a decrease in the desaturation of stearic acid to oleic acid.

Soybean line PI 123440 contains a single nucleotide change in the Fad3c gene encoding the FAD3C enzyme, also known as delta-15 desaturase. The FAD3C enzyme normally inserts a double bond at the delta 15 (omega 3) position of linoleic acid to form alpha-linolenic acid. The mutant allele for the above enzyme results in a decrease in the desaturation of linoleic acid to linolenic acid.

Characterization of the modified plant

No novel DNA has been introduced into the ESS varieties evaluated in this submission, including soybean line HS-2 or any other breeding lines such as A6 and PI 123440 from which HS-2 is derived.

Product information

Based on the information provided, there are no novel proteins produced and only the refined seed oil will be used as food. Refined edible soybean oil does not contain any detectable protein and consists of purified glycosides. The oil profile for ESS varieties average 16-24% stearic acid and <4% linolenic acid. In comparison, regular commodity soybean oil average 3-6% stearic acid, and 8.0% linolenic acid.

Dietary exposure

In North America, soybean is consumed mainly as purified oil utilized in margarine, shortening, and cooking and salad oil. The intended use of high stearate soybean oil from ESS varieties conventionally bred from line HS-2 is as a suitable alternative in food applications where partially hydrogenated soybean oils and/or tropical oils are used.

Nutrition

Compositional data of the ESS were generated in two separate studies in 2005 and 2006 in various locations in the US. As expected, the data demonstrated the intended changes in fatty acid profile. Lectin levels in ESS seeds were slightly above the reported International Life Sciences Institute (ILSI) range, in the 2005 study. This difference is unlikely to pose any nutritional concern, and furthermore, was not observed in the 2006 study.

Compositional data (fatty acids and vitamin E) of oil derived from ESS varieties were also generated in a single study in two locations in the US. As expected, the data demonstrated the intended changes in fatty acid profile. There were no other changes seen that would be of nutritional concern.

Finally, dietary exposure estimates were generated using the US National Health and Nutrition Examination Survey (1999-2002). While overall intakes of stearic acid would be increasing, these increases would be small and of no nutritional concern. There is some evidence suggesting that not all saturated fatty acids have the same physiological effect. Most of the research that has been done indicates that stearic acid may have a neutral effect on cholesterol levels in comparison to other individual saturated fatty acids and carbohydrates.

Based on the US National Health and Nutrition Examination Survey (1999-2002), replacement of partially hydrogenated soybean oil for oil derived from ESS varieties would result in a decrease in the intake of trans fats. Thus, stearic acid may have indirect positive health effects as a consequence of replacing trans fats in the diet.

Toxicology

The available evidence suggests that alterations to the fatty acid profile of ESS is unlikely to adversely alter the expression of endogenous toxins. Substantial equivalence in composition of toxin, anti-nutrient and protein content has been demonstrated between the ESS varieties and the soybean varieties found in the International Life Sciences Institute (ILSI) composition database.

The available evidence suggests that the alterations to the fatty acid profile of ESS varieties is unlikely to express new or unique food allergens, not present in the parental lines. Substantial equivalence in composition of protein content has been demonstrated between ESS varieties and soybean varieties found in the ILSI composition database.

The weight of evidence indicates that the potential exposure to high stearate soybean oil derived from ESS varieties would not pose a toxicological or allergenic concern.

Conclusion

Health Canada's review of the information presented in support of the food use of ESS varieties conventionally bred from line HS-2 concluded that the food use of these soybean varieties does not raise concerns related to safety. Health Canada is of the opinion that ESS varieties are similar to regular commodity soybeans in terms of being an acceptable food source.

Health Canada's opinion deals only with the human food use of ESS varieties conventionally bred from line HS-2. Issues related to the environmental safety of ESS varieties in Canada and its use as livestock feed have been 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 (September 1994).

For further information, please contact:

Novel Foods Section
Food Directorate
Health Products and Food Branch
Health Canada, PL2204A1
251 Frederick Banting Driveway
Ottawa, Ontario K1A 0K9
bmh-bdm@hc-sc.gc.ca