Transcript P3 7 Food irradiation - e

FOOD IRRADIATION
OBJECTIVES
1. Alternative method for food treatment;
2. What is food irradiation?
3. Benefits and changes of foodstuffs.
FOOD IRRADIATION
1. Waves and energy
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FOOD IRRADIATION
1. Energy - >10keV
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FOOD IRRADIATION
2. Types of irradiation used in the food technology
2.1. Non-ionizing
- thermal
- microwaves
- UV light – stimulation of resveratrol production in grapes;
microorganisms killing
UV treatment – might not remove all the microorganisms, especially those
in the inner part of larger particles
UV treatment is applicable for disinfection of water, air, fruit juices etc.
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What is Food Irradiation?
• New commercial technology to eliminate
disease-causing germs
• Comparable to heat pasteurization
• Used for decades in NASA space
missions
• already used for sterilization of:
– medical devices, supplies and implants
– wine corks and other food packaging
materials
– cosmetic ingredients
How Does Food Irradiation
Help?
• food is exposed to carefully controlled
amounts of radiation
• radiation damages DNA of microbes and
parasites
– disease-causing germs are reduced
– bacteria which cause spoiling are reduced
– sprouting is slowed or stopped
What are the Results of
Food Irradiation?
• When used in conjunction with proper food
handling procedures:
– food-borne diseases are reduced or
eliminated
– shelf-life is increased
– the nutritional value of the food is preserved
– the food does not become radioactive
– dangerous substances do not appear in the
foods
FOOD IRRADIATION
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2. Types of irradiation used in the food technology
2.2. Ionizing – allowed in more than 50 countries
1958, Stuttgart, Germany (the first commercially used irradiation – treatment of
spices)
Approval
Food
Purpose
1963
Wheat flour
Control of mold
1964
White potatoes
Inhibit sprouting
1986
Pork
Kill Trichina parasites
1986
Fruit and vegetables
Insect control
Increase shelf life
1986
Herbs and spices
Sterilization
1990 - FDA
1992 - USDA
Poultry
Bacterial pathogen reduction
1997 - FDA
1999 - USDA
Meat
Bacterial pathogen reduction
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2. Types of irradiation used in the food technology
2.2. Ionizing – concerns and regulations
1). safety
2). price – 3-5 millions $ (UHT equipment – 1.5-2 millions $;
equipment for chemical treatment of fruits – 1 million $)
3). consumers’ perception
4). in Europe – the most treated product are frogs' legs, chiken
meat and dried herbs and spices
Radura – symbol of irradiated food
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Facility Accidents and Waste
• Severe accidents are not possible
– electron beam and x-ray sources can be easily
turned off
– gamma ray sources cannot blow up
• The facility itself cannot become radioactive
• no radioactive waste
– used Co-60 gamma sources can be
recycled/regenerated
FOOD IRRADIATION
2. Types of irradiation used in the food technology
2.2. Ionizing – effect of irradiation
Type of food
Effect of Irradiation
Meat, poultry
Destroys pathogenic fish organisms, such as
Salmonella, Campylobacter and Trichinae
Perishable foods
Delays spoilage; retards mold growth; reduces
number of microorganisms
Grain, fruit
Controls insect vegetables, infestation dehydrated
fruit, spices and seasonings
Onions, carrots, potatoes, garlic,
ginger
Inhibits sprouting
Bananas, mangos,papayas,
guavas, other non-citrus fruits
Delays ripening avocados, natural juices.
Grain, fruit
Reduces rehydration time
Some foods – undesirable: milk (flavor)
Peaches and nectarines – softening.
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FOOD IRRADIATION
2. Types of irradiation used in the food technology
2.2. Ionizing – sources
γ – rays: cobalt-60, cesium-137
Х – rays: obtained when electrons beam hits surface of tantalum or tungsten metals.
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FOOD IRRADIATION
2. Types of irradiation used in the food technology
2.2. Ionizing – devices
γ–rays – cobalt-60, cesium-137
Х–rays – obtained when electrons beam hits surface of tantalum or tungsten metals.
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!
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2. Types of irradiation used in the food technology
2.2. Ionizing – dosage and applications
Irradiation
Bellow 1 kGy (weak)
- Inhibition of germination;
- Decontamination;
- Retardation of physiological
processes;
Between 1 to10 kGy (intermediate)
- Prolonging the storage time;
- Elimination of pathogenic
microorganisms;
- Improve of overall technological
process;
Between 10 to 50 kGy (strong)
- Industrial sterilization;
- Disposal of some unwanted
substances.
Dosage, kGy
Products
0.05-0.15
0.15-0.50
0.50-1.00
Potatoes, onion, garlic;
Cereals, vegetables, fish;
Fresh vegetables and fruits
1.00-3.00
1.00-7.00
Fish, strawberries;
Fresh and frozen sea
products and meat (chicken);
Increase of grape juice,
dehydration of vegetables
2.00-7.00
30-50
10-50
Meat (birds, sea products),
ready-to-cook food;
Spices and herbs
1 Gy (Gray) – 1 Joule radiation energy absorbed by 1 kg of matter
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FOOD IRRADIATION
3. Changes of food components – carbohydrates
are generally stable
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3. Changes of food components
Ionizing radiation – lead to
destruction of anthocyanins
(and some pigments)
Ionizing radiation – lead to
formation of new type of components
2-alkylcyclobutanones (2-ACBs).NUTRITION AND CANCER, 44(2),
188–191
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3. Changes of food components
Amounts are for 2.2 pounds (1 kilogram) cooked chicken*
Vitamin
Non-irradiated sample
Irradiated sample
Vitamin A (IU)
2200
2450
Vitamin E (mg)
3.3
2.15
Thiamin (mg)
0.58
0.42
Riboflavin (mg)
2.10
2.25
Niacin (mg)
58.0
55.5
Vitamin B6 (mg)
1.22
1.35
Vitamin B12 (mg)
21
28
Pantothenic acid (mg)
13
17
0.23
0.18
Folic acid (mg)
*E. S. JOSEPHSON, M. H. THOMAS, W. K. CALHOUN. Nutritional Aspects of Food Irradiation: An Overview. Journal of
Food Processing and Preservation. Volume 2, Issue 4, Date: September 1978, Pages: 299-313.
FOOD IRRADIATION
More information:
https://www.youtube.com/watch?v=3NoIwXZFofg;
https://www.youtube.com/watch?v=_9vwS3_s1b4
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