Genetically Engineered Fruits and Vegetables

 
North Central Regional
Extension Publication
NCR #551

Note to the reader: Most genetically engineered fruits and vegetables have not received final approval for marketing from the Food and Drug Administration (FDA) at this time. This publication is designed to explain the science of genetically engineered fruits and vegetables, not to give the perception of pre-approval endorsement by the United States Department of Agriculture (USDA) or by the publishing state.

The Vegetable Revolution

"Eat your vegetables!" has been ringing in children's ears for generations. Today, genetic engineering may enhance the vegetables and fruits they see on their plates.

Genetic (recombinant DNA) engineering is the manipulation of DNA molecules to produce modified plants, animals, or other organisms. DNA (deoxyribonucleic acid) is a double-stranded molecule that is present in every cell of an organism and contains the hereditary information that passes from parents to offspring. This hereditary information is contained in individual units or sections of DNA called genes. The genes that are passed from parent to offspring determine the traits that the offspring will have.

Through the work of the last 20 years, scientists can now isolate the gene or genes for the traits they want in one animal or plant and move them into another. It is not really that simple, since some traits involve more than one gene and some genes are hard to find. Nevertheless, each year scientists are learning better ways to locate and transfer genes.

The Fruit and Vegetable Race

There is stiff competition among companies to bring genetically engineered fruits and vegetables to market. One government official estimates that there are almost 300 projects under way to develop genetically engineered plants (Sugarman). These include the following and many others:

Consumers soon may find firm, "summer-time" tasting
tomatoes year-round in the produce sections of grocery
stores, thanks to the tools of biotechnology.

Tomatoes

Several companies are working on tomatoes that can be vine-ripened and shipped without bruising. (See Leaders of the Race -Two Case Studies.) Others are trying to improve tomatoes that are processed for catsup, soups, pastes, or sauces by genetically engineering them to contain more solids, be thicker, and to contain more lycopene, which provides the red color. One company believes that producing improved or "value added" tomatoes will require a long-term program involving multiple changes. Its research priorities for processing tomatoes are improved viscosity (thickness and texture, meaning fewer tomatoes for the same amount of catsup), higher soluble solids, better taste, improved color, and higher vitamin content. Its objectives for fresh market tomatoes include enhancing overall flavor, sweetness, color, and health attributes.

Potatoes

Genetic engineering is being used to develop potatoes with more starch and less water to prevent damage when they are mechanically harvested. A potato with less water content may absorb less oil when it is fried, producing healthier french fries or potato chips.

Other researchers are using genes from chicken embryos and insect immune systems to try to make potatoes more disease resistant.

Corn

Some companies are trying to transfer a gene into sweet corn to prevent sugars from turning to starch. The new corn would stay sweet longer after it is picked.

Squash and Cantaloupe

One seed company is developing squash and cantaloupe varieties that resist viruses. A piece of a gene from the virus is transferred into the plant where it acts like a vaccine to protect the plants. (See Leaders of the Race - Two Case Studies.)

Another company is working to improve the flavor and sweetness in melons produced for the winter markets. Its researchers believe the same technology can be applied to peaches produced during the main crop season (Eckles).

Strawberries

Bioengineers at one company learned that the Arctic flounder produces an antifreeze to protect itself in freezing waters. They plan to find the gene that regulates production of the antifreeze and introduce it into strawberry plants. Their success would result in strawberry plants that can withstand frosts and berries that don't turn to mush after spending time in the home freezer.

Leaders of the Race Two Case Studies

Tomatoes and squash look like they will finish first and second in the race to put genetically engineered garden produce on the dining table. The development of these new vegetables will be examined in detail to provide a better understanding of how genetically engineered foods move from the laboratory to the grocery store.

The Flavr SavrTM Tomato

The Problem with Winter Tomatoes

Many home gardeners enjoy the taste of vine-ripened tomatoes during the summer. However, consumers in the northern regions of the U.S. must rely on tomatoes shipped in from the South if they want fresh tomatoes during the rest of the year.

To withstand the rigors of shipping, tomatoes must be picked at a stage the growers call "mature-green." Mature-green tomatoes have already absorbed all the vitamins and nutrients from the plant that they can, but have not started to produce the natural ethylene gas that triggers ripening.

The next step, called "degreening" or "ripening initiation," involves putting the green tomatoes in ripening rooms where ethylene gas is released. The green tomatoes spend 3 to 4 days in the ripening room before they are shipped at temperatures not lower than 50 degrees. Cooler temperatures destroy tomato flavor.

When consumers see tomatoes at the grocery store, they probably still are 3 to 4 days away from being ripe. Unfortunately, many consumers think that shipped-in winter tomatoes lack the taste and texture of vine-ripened tomatoes. In fact, according to one study, tomatoes rank #1 in produce items with which consumers are least consistently satisfied (The Packer's Study).

The Flavr Savr Solution

Calgene, Inc., a biotechnology company with headquarters in Davis, California, has developed a tomato with a gene that slows the natural softening process that accompanies ripening. The company says that their Flavr Savr tomato spends more days on the vine than other tomatoes, resulting in more flavor, yet remains firm enough to be shipped.

The Science of Flavr Savr

Pectin, used to make jelly thicken or gel, occurs naturally in many fruits, giving them their firmness. The pectin in ripening tomatoes is degraded by an enzyme called polygalacturonase (PG). As the pectin is destroyed, the cell walls of tomatoes break down and they soften, making them difficult, if not impossible, to ship successfully. Reducing the amount of PG in tomatoes slows cell wall breakdown and produces a firmer fruit for a longer time.

Calgene's scientists isolated the PG gene in tomato plants. The next step was to convert the tomato PG gene into a reverse image of itself called an antisense orientation. The scientists called this "reversed" tomato gene the Flavr Savr gene and reintroduced it into the plants.

In order to tell if the Flavr Savr gene was successfully reintroduced into the plants, Calgene scientists attached a gene that makes a naturally occurring protein that renders plants resistant to the antibiotic kanamycin. By exposing the plants to the antibiotic, Calgene scientists could tell which plants had accepted the Flavr Savr gene. The ones unaffected by kanamycin grow to have the desired traits of the Flavr Savr.

Once in a tomato plant, the Flavr Savr gene attaches itself to the PG gene. With the Flavr Savr gene adhering to it, the PG gene cannot give the necessary signals to produce the polygalacturonase enzyme that destroys pectin. One way of visualizing this is to imagine how hard it would be for people to function if we each had a mirror image of ourselves stuck to us.

If approved by the FDA, those plants with the Flavr Savr TM gene will be grown for commercial tomato production. The seeds will be planted and grown like any other fresh tomato plants, except the tomatoes can spend more days on the vine until they reach the desired flavor and texture before shipping. (Figure 1 summarizes the process.)


Figure 1

From Laboratory to Market

In 1992, Calgene, Inc., established a wholly owned subsidiary named Calgene Fresh, Inc., to produce, market, and sell highquality branded fresh produce to the retail grocery and food service markets. Calgene Fresh moved the Flavr Savr tomato from the experimental stages to commercial production step-by-step.

1. Market Demand

Before introducing any new product, including genetically engineered fresh produce, a company must be sure that the product has a market. Domestic consumption of fresh tomatoes is estimated at about 5 billion pounds a year with an estimated retail value of approximately $33.5 billion (Calgene, factsheet). Calgene Fresh, Inc., estimates that 85 percent of U.S. households purchase fresh tomatoes each year, with more than 50 million consumers purchasing three pounds of fresh tomatoes in a typical month. This level of consumption is occurring despite consumer dissatisfaction with the quality of fresh tomatoes.

2. Patenting the Technology

Patents protect a company's legal rights to a technology it invented. In February 1989, Calgene, Inc., was issued a U.S. patent on the use of the tomato polygalacturonase (PG) gene sequence, including the antisense (reverse) orientation of the gene. In April 1992, the company was issued a broad patent covering the use of the antisense technology in all plants to partially or completely inhibit specific gene expression.

After a patent is issued, other companies may challenge the patent if they believe they developed the technology first. At least two companies are challenging Calgene's patenting of the technology used to develop the Flavr Savr tomato.

3. Pre-market Testing

The FDA and the USDA require a company to conduct rigorous pre-market testing of genetically engineered food products before they become commercially available. The Flavr Savr tomato is probably the most studied tomato in history. It has undergone more than four years of comprehensive pre-market tests that examined the nutritional value, potential toxins, processing and horticultural traits, fungal resistance, softening rate, and other characteristics. In addition, Calgene Fresh, Inc., voluntarily submitted its safety data for rigorous review by an external panel of nationally recognized food safety experts. Their studies demonstrate that the Flavr Savr tomato is as safe and nutritious as any other fresh tomatoes.

Test results were submitted to both the FDA and the USDA, opened for public comment by both agencies, and published in a technical report that is available to the public (Redenbaugh et al.).

4. Regulatory Status

The FDA regulates food and food additives, including new genetically engineered foods. The USDA regulates whether genetically engineered plants can be grown and under what conditions.

In November 1990, Calgene requested an Advisory Opinion from the FDA on the use of the kanamycin resistance marker gene in tomatoes. In October 1991, it requested the FDA to issue a separate Advisory Opinion on the status of the Flavr Savr tomato as a food (under regulatory definition). To assure a thorough review of the safety of the new product, the company subsequently asked the FDA to review the marker gene used in the Flavr Savr as a food additive.

In May 1992, the company filed a Petition for Determination with the USDA requesting that the agency determine that the Flavr Savr tomato is a non-regulated article under federal law. In October 1992, the USDA determined the Flavr Savr tomato does not present a plant pest risk and therefore need not be regulated.

5. First on the Market

In April of 1994, outside experts of the FDA's Food Advisory Committee discussed the agency's evaluation of the Flavr Savr tomato in a public meeting. Members of the committee agreed with the FDA's preliminary assessment that all relevant safety questions about the new tomato had beer) resolved.

On May 18,1994, the FDA announced its findings that the Flavr Savr tomato is as safe as tomatoes bred by conventional means, in effect giving Calgene Fresh approval to market its new product. Calgene Fresh immediately began offering limited quantities of the new tomatoes grown from Flavr Savr seeds under the MacGregor'sR brand in selected midwestern and California markets.

Virus Resistant Squash

In July 1992, Asgrow Seed Company, the agricultural division of The Upjohn Company of Kalamazoo, Michigan, became the second company to ask the USDA to rule on the status of a genetically engineered crop, the ZW-20 virusresistant squash. This yellow crookneck squash has been modified to resist watermelon mosaic virus-2 (WMV-2) and zucchini yellow mosaic virus (ZYMV).

The Problem of Squash Viruses

Commercial production fields of squash suffer from several viruses, including WMV-2 and ZYMV. The viruses are transmitted by aphids when they feed on the plants. Infected plants develop fruits that are distorted and discolored, cutting the yield of marketable squash.

Current methods of controlling the viruses focus on controlling aphids through repeated spraying of insecticides or oils. These preventive measures have failed to effectively control aphids that spread the viruses.

The ZW-20 Solution

Asgrow has developed a yellow crookneck squash that can resist both WNW-2 and ZYMV viruses.

This approach bypasses aphid control methods to focus on the viruses themselves. The number of aphids in a squash field is less important if the squash cannot be infected by the disease they transmit.

The Science Behind ZW-20

Asgrow scientists used a method of gene transfer called Agrobacterium tumefaciens-mediated transformation to produce the new squash. (See the left side of Figure 2.) Agrobacterium tumefaciens is a bacteria that can be used to transfer genes into the chromosomes of plant cells.

The genes that produce the coat protein of the two viruses WMV-2 and ZYMV were introduced into the bacteria. Two DNA molecules called plasmids that were located within the bacteria transferred the two virus genes into squash plant cells.

Once inside the squash plant cells, scientists hoped the virus genes would become part of the squash plant's DNA, "vaccinating" it against the viruses. To be sure, Asgrow scientists attached marker genes for the antibiotic neomycin phosphotransferase to the virus genes before they were introduced into the bacteria. Plant cells containing the marker gene with the attached virus genes could grow more rapidly in the presence of the antibiotic than those that did not.

Scientists selected the plant cells that they knew had the virus genes and grew them into plants. With subsequent selections, researchers were able to separate the marker genes from the resistance genes, so the ZW-20 line contains no marker genes for antibiotic resistance.

From Laboratory to Market

Like Calgene, Asgrow is following a step-by-step process to move the ZW-20 squash to commercial status.

1. Market Demand

Commercially acceptable squash varieties currently do not exist that can resist even one of the four most common viruses that affect squash. Asgrow believes that genetic engineering offers a means of developing squash hybrids that are protected from virus infection without altering the plants' desirable commercial or horticultural characteristics.

2. Patenting the Technology

Asgrow has applied for patents to protect the technology and the plants made resistant to the viruses by this approach. No decision has been made by the Patent Office regarding these applications, as this is written.

3. Pre-market Testing

Pre-market tests of the ZW20 squash compared its disease and pest resistance, pollination characteristics, weediness, possibility of genetic transfer to related species, mixing of the viral coat proteins with other virus proteins, and safety for human consumption to that of traditional squash plants. According to Asgrow, nutritional comparisons were not done because all squash is low in food value and does not contribute significantly to consumers' nutrient intake. Except for its resistance to the targeted viruses, the data indicated that the ZW-20 squash has the same horticultural characteristics as traditional varieties.

Asgrow says that the new squash carries no more risk of developing undesirable characteristics, and sometimes less, than traditional squash plants. For example, the company examined squash from supermarket shelves and found higher protein levels of WMV-2 and ZYMV viruses within fruit from plants that had been naturally infected with viruses in the fields than in the ZW-20 squash.

Pre-market testing results submitted to the USDA's Animal and Plant Health Inspection Service are available to the public from that agency.

4. Regulatory Status

In July 1992, Asgrow asked the USDA to deregulate the ZW_20 modified squash plant because the company does not believe that the plant presents a plant pest risk or is otherwise harmful to the environment. After reviewing the data provided by Asgrow and opening the data for public comment, the USDA requested additional data, which Asgrow has provided, and asked for more public input. In May of 1994, the USDA determined in a preliminary finding that the ZW-20 squash would not have a negative impact on the environment and opened a third period for public comment. According to a company spokesman, Asgrow is planning commercial introduction of the squash, after regulatory approval (Ag Biotechnology News).


Figure 2 - This diagram illustrates how two of the techniques of biotechnology, Agrobacterium (top left) and a particle gun (top right), are used to transfer DNA from one orginism to another.  Note that after gene transfer is accomplished, the remaining steps for producing transgenic plants are the same for either method.

Federal Regulation of Genetically Engineered Foods

The FDA has the primary responsibility for regulating food additives and new foods, except meat and poultry products, which are regulated by the USDA. The FDA works closely with the USDA on food safety matters and with the U.S. Environmental Protection Agency, which regulates pesticides and sets tolerances for pesticide residues in food.

In May 1992, the FDA determined that foods derived from new plant varieties essentially will be regulated no differently than foods created by conventional means, unless special circumstances apply (Federal Register). The FDA released guidelines to help companies decide whether they need FDA approval of a genetically engineered food product. The FDA determined that a special review of a genetically engineered food product would be needed only when specific safety issues were raised, such as if the gene for peanut protein, to which some people are allergic, was inserted into a different food like a tomato. Specifically, companies were told that an evaluation to assure food safety may be required if one or more of the following subheadings apply to their product (Federal Register):

1. Unexpected Effects (produces unexpected genetic effects)

2. Known Toxicants (has significantly higher levels of toxicants than present in other edible varieties of the same species)

3. Nutrients (significantly alters levels of important nutrients)

4. New Substances (differs significantly in composition from such substances currently found in food)

5. Allergenicity (contains proteins that cause an allergic response)

6. Antibiotic Resistance Selectable Markers (contains marker genes that could produce antibiotic resistance in people who consumed the food)

7. Plants Developed to Make Specialty Nonfood Substances (plants developed to make substances like pharmaceuticals or polymers that will also be used for food)

8. Issues Specific to Animal Feeds (plants that will be used for animal feeds)

 The FDA also declined to require all genetically engineered food products to be labeled as such solely because they involved genetic engineering. However, it recognized that in certain situations consumers should be advised through labeling, such as when the genes for proteins to which some people are allergic are transferred from one species to another.

The FDA policy notice of May 1992 may be revised in the future as the agency responds to new scientific developments and the comments of the public and the scientific community.

The Consumer Debate

Consumer and industry groups are expressing their views about genetically engineered foods. Some organizations actively oppose their development, while others work equally as hard to support biotechnology research.

For example, in June of 1992, shortly after the FDA's policy notice was released, a group of New York City chefs called for an international boycott of genetically engineered foods. About the same time, a coalition of farmers, consumers, and environmentalists known as The Pure Food Campaign petitioned the FDA for government-required testing and labeling of all genetically engineered foods.

In contrast, a USDA-supported survey of 1,200 consumers nationwide found that nearly two-thirds (64 percent) supported using biotechnology to produce food (Food Insight). In the same survey, 71 percent agreed that biotechnology could benefit people like themselves, and 66 percent expressed interest in learning more about biotechnology.

Several food industry groups, including the Grocery Manufacturers of America (GMA) and the Produce Marketing Association (PMA) have issued position papers expressing confidence in the safety of foods developed through biotechnology (GMA, PMA). The GMA paper cites findings by the American Medical Association's Council on Scientific Affairs, a Joint FAO/ WHO Consultation released by the World Health Organization, the National Research Council, and the FDA that foods developed through biotechnology are similar to other foods developed by traditional methods and are not inherently less safe.

The American Dietetic Association has written a position paper concerning biotechnology and the future of food. It is their position that the techniques of biotechnology are useful for the improvement of food quality, nutritional value, and variety and for making the production, processing, distribution, and waste management of food more efficient (Journal of American Dietetic Assoc.). The position paper advises dietetics professionals to understand the vocabulary and implications of biotechnology and to accept the role of consumer advocates in questions of labeling and regulation of foods developed through biotechnology techniques.

Not everyone views genetically engineered foods, including fruits and vegetables, as a welcome development. Consumer groups, some with international organizations, have expressed concerns in several areas. Some proponents of using biotechnology to produce food point out that opponents' objections are not always as valid as they seem.

Nutritional Value

Some people are concerned that genetically altering foods could change their nutritional value by lowering vitamin content or other nutrients.

Others point out that several companies have genetic engineering projects under way to increase, not lower, the health attributes of foods.

Gene Transfers

There is some concern that the process of inserting genes is not precise. Scientists cannot tell exactly where they go or how many reach their target, necessitating the need for marker genes, many of which are resistant to an antibiotic.

Proponents assert that genetic engineering is more precise than traditional crossbreeding methods and carries less risk of undesired traits being transferred. In traditional methods, thousands of genes are passed on with each generation, besides the gene of interest. Genetic engineers can narrow the transfer to the genes they select.

Gene Interactions

Some fear that a foreign gene may not behave in a new crop the way it did in the original species. It may interact with genes around it or with its new environment to produce undesirable traits.

The FDA does not view the problem of unexpected genetic effects as unique to genetic engineering. In its May 1992 policy statement, the agency points out that "virtually all breeding techniques have potential to create unexpected effects" (Federal Register).

About 25 years ago, a plant breeder in Canada, experimenting with a new potato variety developed by the USDA for its disease resistance, reportedly became ill after eating some. Evidently, levels of a naturally occurring toxin in the potato were elevated during the traditional breeding process.

The FDA notes that today's traditional plant breeders use well established practices to eliminate plants with adverse traits prior to commercial use. Presumably, plant breeders that help bring transgenic plants to market can do the same

Marker Genes Remaining in Foods

Critics point out that marker genes used to help scientists find plant cells that were successfully transformed may remain in the food. Opponents claim that if the marker gene produces resistance to an antibiotic, it might reduce the effectiveness of the antibiotic if taken simultaneously with the bioengineered food.

The FDA, in its May 1992 policy notice, recognized the importance of evaluating concerns about the commercial use of antibiotic resistance marker genes in food, especially those to be used widely. The FDA noted that the agency is currently evaluating these issues as they apply to the kanamycin resistance marker gene. In addition, some scientists are working to develop ways to remove marker genes from a plant after the gene transfer is made.

Allergens

The FDA requires labeling of foods containing known proteins to which people are allergic. Many people are allergic to peanuts, so genetically transformed food involving genes for peanut protein must be labeled, However, in its May 1992 policy notice, the FDA said it was unaware of practical methods to predict the potential for new food proteins to induce an allergic response and requested comments on this issue.

Biotechnology supporters argue that the FDA already has advised companies to thoroughly test and label genetically engineered foods that contain known allergens. Some say that because there currently is no practical way to predict which new proteins will produce an allergic response, testing and labeling is all that can be reasonably expected at this point.

Special Populations

Concerns have been raised about the effect of genetically engineered foods on special populations, such as infants or people suffering from ulcers or other conditions or diseases. The assumption is that company testing is done on healthy adults, so effects that might emerge in other populations could be missed.

On the other hand, it can be argued that this situation is not unique to genetically engineered foods. Practicality prevents testing any new product on every specialized population before it is marketed.

Accidental Toxicity

The FDA requires that foods with known toxins be thoroughly studied. Some fear a synergistic reaction between two food compounds that may be harmless separately, but together could be toxic. Others have voiced concerns that harmless plants that have toxic relatives may inadvertently have the "toxic" gene turned on. For example, tomatoes are related to the poisonous nightshade family.

Genetic changes that can lead to unexpected toxins can occur not only in genetically transformed plants, but also in plants developed through traditional breeding practices or as a natural part of growth. Proponents agree with the FDA view that the likelihood that food plants with a long history of use will develop unexpected toxins is "extremely low."

Herbicide and Pesticide Resistance

Research continues on plants that can withstand herbicide and pesticide treatments designed to kill weeds and insects that cut their production. Some people fear that the genes for resistance will somehow be passed to the weeds and insects may build up a resistance to the new pesticide. Some think that a gene that is intended to be toxic only for insects will somehow mutate and become toxic to humans as well.

Others cite the fact that the potential of pests to develop resistance against the defense mechanisms of crops is well-known and is not unique to genetically engineered plants. Insects may develop resistance to a crop defense no matter how it was developed. The crop defense might be a chemical or biological agent, a gene already in the crop species and transferred to commercial plants by conventional plant breeding methods, or a gene introduced by recombinant DNA technology. Companies are working on strategies to avoid possible resistance problems.

Inadequate Approval Process

There are individuals who see a distinct conflict of interest in the practice of relying on a company's own scientific data to determine food safety. They call for more independent testing by the FDA or independent laboratories to verify company results.

Proponents maintain that every company or individual that produces food by using recombinant DNA technology is legally responsible for assuring its safety and quality before it enters the food supply.

Some companies resent the implication that test results from their own laboratories are false. After all, they argue, it's to their benefit to produce a safe, beneficial food product for consumers. There's no profit in bad products. Besides, many companies engage independent laboratories to test their products. Calgene Fresh, Inc., for example, submitted its safety data on the Flavr SavrTM TM tomato to an external panel of nationally recognized food safety experts for rigorous review. The reality is that today's FDA does not have the people or the money to conduct its own tests on every new food product.

Diversity of Species

Some critics of genetically engineered plants foresee the day when growers will all want one "perfect" variety, opening the door to disasters like the U.S. corn blight twenty years ago. Others fear that new plant species may upset the balance of nature, changing delicate relationships between crop plants, weeds, and animals that consume them.

Supporters of biotechnology foresee a different day when not one, but many improved crop varieties could flourish in areas of the world that currently cannot produce enough food crops for their populations.

Labeling

A central issue for many opponents of genetically engineered foods is labeling. Some groups want all genetically engineered foods labeled as such to provide consumers the right to choose. Current FDA policy requires labeling based on several factors, such as composition changes or allergy concerns, but not solely because the development of a food involved genetic engineering.

Others point to the need for labeling for individuals whose religions or lifestyles have dietary restrictions. For example, eating fruit that has been transformed with an animal gene may be objectionable to vegetarians or to members of a religion that forbids eating meat from that animal.

Most supporters of genetically engineered foods recognize the need for labeling if the composition of a food has changed substantially or allergens or toxins are a possibility. However, some worry that labels placed on all genetically engineered foods would be interpreted as warning labels.

Calgene Fresh says it intends to voluntarily identify its Flavr Savr tomato and will provide consumers with "point-of-purchase materials that explain the role of biotechnology in delivering a better tasting tomato" (Calgene, Questions and Answers).

The Debate Goes On

Debate about genetically engineered foods is healthy, and the concerns being raised by consumer are not falling on deaf ears. While the debate goes on, the companies developing genetically engineered products are working to address consumer concerns. These firms point out that their products undergo years of rigorous research to assure consumers that the U.S. food supply, one of the safest in the world, will remain so.

What To Expect

As this is written, Calgene Fresh is marketing Flavr SavrTm tomatoes. After seeing how they fare, products from other companies may not be far behind.

In fact, one seed company plans to release improved tomatoes and melons in the mid to late 1990s with enhanced vitamin-content tomatoes available about 2000 (Eckles). It is also developing projects to improve the texture and taste of other high value soft fruits, such as peaches and strawberries. These products will probably hit the market in the late 1990s to 2000.

The bottom line for genetically engineered foods will be the products' own merit, consumer trust, and economics. Will consumers be afraid to eat a genetically engineered tomato, even if it does look red and juicy in January? If they are willing to eat it, will they be willing to pay for it?

No doubt, the years of research, development, and testing required to develop a new genetically engineered food will demand a higher price at the grocery store. Calgene Fresh has already declared that the "value delivered in the Flavr Savr tomato will command a premium price" (Calgene, Questions and Answers).

Whether the premium price of genetically engineered vegetables, in trust as well as dollars, is too high is something consumers will decide.

References

Ag Biotechnology News. "More Data Needed on Asgrow Squash." November 1992. p. 16.

Calgene Fresh, Inc. "Fact Sheet: Flavr Savr Tomatoes." 1033 University Place, Suite 450 , Evanston, Illinois 60201, p 1.

Calgene Fresh, Inc. "Flavr Savr Tomato: Questions & Answers." 1033 University Place, Suite 450, Evanston, Illinois 60201, p 2-3.

Canine, Craig. "A Matter of Taste ... Who Killed the Flavor in America's Supermarket Tomatoes?" Eating Well. January/ February 1991, p. 41-55.

Dyson, John. "The Amazing GreenGene Revolution." The Reader's Digest. October, 1992, p. 53-57.

Eckles, Jim. Personal and written communication. Zeneca Ag Products, a subsidiary of Imperial Chemical Industries. Wilmington, Delaware, 29 March 1993.

Federal Register. "Statement of Policy: Foods Derived from New Plant Varieties; Notice." Part IX, Department of Health and Human Services, Food and Drug Administration, Vol. 57, No. 104, Friday, May 29, 1992, p. 22984-23005.

Food Insight. "Consumers Support Use of Food Biotech." September/ October 1992. p. 6.

Grocery Manufacturers of America, Inc. "Safe Foods Developed Through Biotechnology: Nutritious, healthful, abundant and good tasting." 1010 Wisconsin Avenue, N.W., Washington, D.C. 20007. October 1992.

Journal of the American Dietetic Association. "Position of The American Dietetic Association: Biotechnology and the Future of Food." Vol. 93, No. 2, February 1993. p. 189-192.

Krimsky, Sheldon. "Tomatoes May Be Dangerous to Your Health." The New York Times. 1 June 1992, Op-Ed page.

Monsanto. "Tomatoes With Lasting Flavor." The Agricultural Group, 700 Chesterfield Parkway North, St. Louis, Missouri 63198.

Produce Marketing Association. "Produce Marketing Association Position Paper on Biotechnology." 1500 Casho Mill Road, P.O. Box 6036, Newark, Delaware 19714-6036. October 1992.

Redenbaugh, Keith; Hiatt, W.; Martineau, B.; Kramer, M.; Sheehy, R.; Sanders, R.; Houck, C.; and Emlay, D. Safety Assessment of Genetically Engineered Fruits and Vegetables: A Case Study of the Flavr SavrTM Tomato. Boca Raton, Florida: CRC Press, Inc., 1992. ISBN 0-8493-4803-X.

Sagan, Kathyrne V. "The Great Tomato Debate ... Is Bioengineered Food Safe?" Family Circle, October 13, 1992, p. 151-160.

Sugarman, Carole. "Splice and Dice -Genetic Engineers on the Cutting Edge." The Washington Post. 3 June 1992, p. El, E4.

The Packer's 1993 Fresh Trends Consumer Profile Study, p 82.
 
 

Written by Glenda D. Webber, Office of Biotechnology, Iowa State University, Ames, Iowa. Credits

Page 1 Photo courtesy of Monsanto.
Page 3 Figure courtesy of Calgene Fresh,Inc.
Page 5 Diagram, based on graphic supplied by Monsanto

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November, 1994