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EMB Workshop for
GM Food, Food Labeling &
Food Additives
The Chinese University of
Hong Kong
Lai K. Leung, PhD
Food & Nutritional Sciences Programme
( Biochemistry Department)
MSc Programme in Nutrition, Food
Science and Technology
Diploma/Certificate in Food & Nutritional
Sciences
19/11/05
GM Food
• Definition:
– A food product
containing some
quantity of any
genetically modified
organism (GMO) as an
ingredient.
19/11/05
GM Food
• Common GM Food in the
market:
–
–
–
–
Rice
Soybean
Corn
Tomato
• Purpose:
– Securing food supply (fastgrowing; resistant to
temp/virus/insecticide)
– Economic factor
– Nutrient enrichment
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GM Food
• Technique:
VECTOR
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GM Food
• History:
– 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 (selfdestruction of offspring);
withdrawal due to public
opposition.
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GM Food
• Hong 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 system:
Polymerase Chain Reaction
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GM Food
• Issues:
– 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 2500kcalorie 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.
19/11/05
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
19/11/05
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.
2.
3.
4.
5.
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Aspartame
Saccharin
Sugar alcohols
Acesulfame-K
sucralose
Acesulfame-K
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“... 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."
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.
19/11/05