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19/11/05
EMB Workshop for EMB Workshop for GM Food, Food Labeling & GM Food, Food Labeling &
Food AdditivesFood Additives
Lai K. Leung, PhDLai K. Leung, PhD
Food & Nutritional Sciences Programme Food & Nutritional Sciences Programme ( Biochemistry Department)( Biochemistry Department)
MSc Programme in Nutrition, Food MSc Programme in Nutrition, Food Science and TechnologyScience and Technology
Diploma/Certificate in Food & Nutritional Diploma/Certificate in Food & Nutritional SciencesSciences
The Chinese University of The Chinese University of Hong KongHong Kong
19/11/05
GM Food
• DefinitionDefinition:
– A food product containing some quantity of any genetically modified organism (GMO) as an ingredient.
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GM Food• Common GM Food in the Common GM Food in the
marketmarket:– Rice– Soybean– Corn– Tomato
• PurposePurpose:– Securing food supply (fast-
growing; resistant to temp/virus/insecticide)
– Economic factor– Nutrient enrichment
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GM Food
• TechniqueTechnique:
VECTOR
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GM Food• HistoryHistory:
– 1st GMF in the US market – tomato produced by Calgene in 1994; flavor not desirable, pulled out in 1997.
– Monsanto & USDA in 1998 patent on a technique for genetic seed sterilization (self-destruction of offspring); withdrawal due to public opposition.
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GM Food
• Hong KongHong Kong:– No farmers using GM technique.– Research performed at the Univ. level.– No specific regulation for GM food sale.– Public consultation on GM food labeling in
2001. – An impact assessment conducted in 2002.– 2003, difficulties were identified in mandatory
GM food labeling.– The Govm’t’s initiative: only safe GM food are
sold.
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GM Food
• Testing systemTesting system:
Polymerase Chain Reaction
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GM Food
• IssuesIssues:– Benefits (↑productivity & quality; ↓cost)– Potential hazards (food allergy; jeopardized
flora & fauna biodiversity; delayed response for long term consumption)
– Consumers’ right?
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Food Labeling (FL)
• FL provides the info for calculating the nutritional values. It consists of percentages of the Daily Values.
• Assist individuals to pursue a healthy dietary pattern.
• Chronic disease prevention and gov’t budget implication.
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Food Labeling (FL)
• The Daily Values:– Developed by FDA on FL for simplifying the
calculation of intake.– The % based on a 2000-kcalorie and/or 2500-
kcalorie diet.– 2000 kcalorie diet: about right for moderately
active women, teenage girls, and inactive men.
– 2500 kcalorie diet: about right for men, teenage boys, and active women.
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Food Labeling (FL)
• Nutrient claims:– Claims must be coherent physiologically.– e.g. “cholesterol-free” claim has to satisfy <2
mg of chol and also ≤ 2 g of saturated fat per serving.
• Health Claims– Related to a disease or health condition (most
people/specific population are at risk).– Supported by scientific evidence.
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ABC News
• Recent food labeling issues in the US:
– ABC News Watchdog Group Calls Out Food Products Mislabeled 'Healthy'.htm
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Food Additives
• ‘Any substance that affects the characteristics of any food.’– Coloring agents– Sweeteners– MSG, etc.
• Food Toxicology
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Food Toxicity
• Definition:– “the capacity of a
substance to cause adverse health effects on a living organism.”
– Paracelsus commented in the 15th century, “All substances are poisons; there is none which is not a poison. The right dose differentiates a poison and a remedy.”
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Food Additives
• Purpose:– Product consistency, texture, etc. – Nutrition value – Storage– Taste, attractiveness.
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• For sweetness without the taking in that much calories as sugar.
US FDA approved sweeteners
1. Aspartame
2. Saccharin
3. Sugar alcohols
4. Acesulfame-K
5. sucralose
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Acesulfame-K
“... acetoacetamide, a breakdown product, has been shown to affect the thyroid in rats, rabbits, and dogs. Administration of 1% and 5% acetoacetamide in the diet for three months caused benign thyroid tumors in rats. The rapid appearance of tumors raises serious questions about the chemical carcinogenic potency."
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Saccharin
• It causes bladder cancer in rats, but the dosage is too high (equivalent to hundreds of cans of diet drinks per day).
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Cyclamate
• Not approved yet. It causes bladder cancer in rats.
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Issues to be addressed
Projects can be focused on:• Environmental impact. • How to implement?• What are the potential difficulties?• Identify the ‘losers’ of any of these
new policies.• Are we overly cautious?• What are the new opportunities?
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My recommendation
• Grade the project as essays with science elements.
• Not scientific papers.