Links:
http://www.health.vic.gov.au/foodsafety/downloads/histamines_biogenicamines1995.pdf
Histamines in fish
In three studies on histamines in fish conducted on behalf of the Department of Human Services (DHS), as many as 51 percent of seafood products tested exceeded the permitted level for histamines. Histamines in fish can cause allergic reactions in people ranging from mild skin discomfort to nausea, vomiting and diarrhoea.
The level of histamine in fish, canned, frozen or fresh is affected by the presence of certain proteins which are converted to allergenic products by bacteria present. Correct temperature control can limit the production of histamines.
The number of products over the limit, in canned fish products in particular, prompted the DHS to conduct further research during 2000 into the affect of storage time and temperature on histamine production to determine whether existing food handling practices were adequate. The 2000 study concluded that if appropriate temperature control practices were followed, production of histamine was limited.
The standard states that“the level of histamine in acomposite sample of fish or fish products, other than crustaceans or molluscs, whenexamined according to the method in Section 977.13 of A.O.A.C, l5th Edition (1990), must not exceed 100mg/kg. Levels above 100mg/kg indicate that fish have been mishandled during storage or processing.
Links:
http://www.medscape.com/medline/abstract/15620882
http://www.potatocongress.org/sub.cfm?source=108
Glycoalkaloids in potato
Glycoalkaloids are natural toxins, occuring in all parts of plants of the Solanum species. Glycoalkaloids are toxic to humans; the lethal dose is considered to be 3-6 mg per kg body mass. Commercial and especially new potato varieties are routinely screened at the Netherlands Institute for Carbohydrate Research TNO for their solanidine glycoalkaloid content, with a HPLC method
Comparison of rapid liquid chromatography-electrospray ionization-tandem mass spectrometry methods for determination of glycoalkaloids in transgenic field-grown potatoes.
Two rapid methods for highly selective detection and quantification of the two major glycoalkaloids in potatoes, alpha-chaconine and alpha-solanine, were compared for robustness in high-throughput operations for over 1000 analytical runs using potato tuber samples from field trials. Glycoalkaloids were analyzed using liquid chromatography coupled to tandem mass spectrometry in multiple reaction monitoring mode.
An electrospray interface was used in the detection of glycoalkaloids in positive ion mode. Classical reversed phase (RP) and hydrophilic interaction (HILIC) columns were investigated for chromatographic separation, ruggedness, recovery, precision, and accuracy.
During the validation procedure both methods proved to be precise and accurate enough in relation to the high degree of endogenous biological variability found for field-grown potato tubers. However, the RP method was found to be more precise, more accurate, and, more importantly, more rugged than the HILIC method for maintaining the analytes' peak shape symmetry in high-throughput operation.
Saturday, June 30, 2007
Thursday, June 28, 2007
What are Genetically Modified (GM) Foods
Links:
http://www.ars.usda.gov/is/AR/archive/jan05/food0105.htm
Genetically modified food are changing the genetic makeup of living organisms such as animals, plants or bacteria by combining the genes from different organisms using a set of technologies known as DNA technology.
Combining genes from different organisms is known as recombinant DNA technology, and the resulting organism is said to be "genetically modified," or "genetically engineered," or "transgenic." GM products include medicines and vaccines, foods and food ingredients, feeds, and fibers
Locating genes for important traits—such as those conferring insect resistance or desired nutrients—is one of the most limiting steps in the process. However, genome sequencing and discovery programs for hundreds of different organisms are generating detailed maps along with data-analyzing technologies to understand and use them.
There were some planted transgenic crops, the principal ones being herbicide- and insecticide-resistant soybeans, corn, cotton, and canola.
Example;
Bananas that produce human vaccines against infectious diseases such as hepatitis B; fish that mature more quickly; fruit and nut trees that yield years earlier, and plants that produce new plastics with unique properties.
http://www.ars.usda.gov/is/AR/archive/jan05/food0105.htm
Genetically modified food are changing the genetic makeup of living organisms such as animals, plants or bacteria by combining the genes from different organisms using a set of technologies known as DNA technology.
Combining genes from different organisms is known as recombinant DNA technology, and the resulting organism is said to be "genetically modified," or "genetically engineered," or "transgenic." GM products include medicines and vaccines, foods and food ingredients, feeds, and fibers
Locating genes for important traits—such as those conferring insect resistance or desired nutrients—is one of the most limiting steps in the process. However, genome sequencing and discovery programs for hundreds of different organisms are generating detailed maps along with data-analyzing technologies to understand and use them.
There were some planted transgenic crops, the principal ones being herbicide- and insecticide-resistant soybeans, corn, cotton, and canola.
Example;
Bananas that produce human vaccines against infectious diseases such as hepatitis B; fish that mature more quickly; fruit and nut trees that yield years earlier, and plants that produce new plastics with unique properties.
Saturday, June 23, 2007
Benefits and Controversies surrounding GM foods
Links:
http://www.ornl.gov/sci/techresources/Human_Genome/elsi/gmfood.shtml
Benefits
Crops
It enhances the taste and quality, more importantly improved resistance to disease, pests and herbicide. The time needed to grow the GM crops also minimizes as the maturation time reduces. New products can be developed and GM crops could have the increased nutrients with the developed of GM technology. Furthermore, the farmers get higher yields using GM seeds to grow their crops. Consumers can also have more choices such as herbicide-tolerant soybeans and the Flavr Savr tomato which is more resistance to rotting.
Animals
There will be better yields of animal’s meats and its’ secondary products such as eggs and milks. Furthermore, it helps to improve animal health and increase resistance, productivity, hardiness and feed efficiency.
Society
It gain increased food security for the growing populations, because of the extra yields that the GM food provides.
Environment
Environment is protected because herbicide and insecticide does not need to be used. It helps to conserve soil, water, energy and has better natural waste management. Furthermore, it helps to prevent global warming.
Controversies
Safety
It has potential human health impact such as allergens. It has potential environment impact such as unintended transfer of trans-genes through cross-pollination, loss of flora and fauna biodiversity
Product labeling
There will be problem during labeling when the GM crops mixes with non-GM crops as it confounds labeling attempts.
Ethics
There are concerns over the abuse of natural organisms’ intrinsic values and tampering with nature by mixing genes among species. As such, vegetarians and some religious people who do not consume meat may be offended because of the objections to consume animal genes in plants and vice-versa.
Intellectual property
It may not be too good if the developing countries are over dependence on industrialized nations and the domination of world food production by few companies. There is also a problem due to foreign exploitation of natural resources.
Society
New technology may be skewed towards the rich because GM seeds are more expensive than the non-GM seeds. As a result, the rich will become richer while the poor become poorer.
Conclusion
GM foods brings about advantages to farmers, as well as consumers. This is because with the developed of GM foods, there will be higher yielding of crops, resulting in more money earned by the farmers. With the developed of GM techniques, the foods can have more nutrients and better quality. Thus, benefits the consumers.
http://www.ornl.gov/sci/techresources/Human_Genome/elsi/gmfood.shtml
Benefits
Crops
It enhances the taste and quality, more importantly improved resistance to disease, pests and herbicide. The time needed to grow the GM crops also minimizes as the maturation time reduces. New products can be developed and GM crops could have the increased nutrients with the developed of GM technology. Furthermore, the farmers get higher yields using GM seeds to grow their crops. Consumers can also have more choices such as herbicide-tolerant soybeans and the Flavr Savr tomato which is more resistance to rotting.
Animals
There will be better yields of animal’s meats and its’ secondary products such as eggs and milks. Furthermore, it helps to improve animal health and increase resistance, productivity, hardiness and feed efficiency.
Society
It gain increased food security for the growing populations, because of the extra yields that the GM food provides.
Environment
Environment is protected because herbicide and insecticide does not need to be used. It helps to conserve soil, water, energy and has better natural waste management. Furthermore, it helps to prevent global warming.
Controversies
Safety
It has potential human health impact such as allergens. It has potential environment impact such as unintended transfer of trans-genes through cross-pollination, loss of flora and fauna biodiversity
Product labeling
There will be problem during labeling when the GM crops mixes with non-GM crops as it confounds labeling attempts.
Ethics
There are concerns over the abuse of natural organisms’ intrinsic values and tampering with nature by mixing genes among species. As such, vegetarians and some religious people who do not consume meat may be offended because of the objections to consume animal genes in plants and vice-versa.
Intellectual property
It may not be too good if the developing countries are over dependence on industrialized nations and the domination of world food production by few companies. There is also a problem due to foreign exploitation of natural resources.
Society
New technology may be skewed towards the rich because GM seeds are more expensive than the non-GM seeds. As a result, the rich will become richer while the poor become poorer.
Conclusion
GM foods brings about advantages to farmers, as well as consumers. This is because with the developed of GM foods, there will be higher yielding of crops, resulting in more money earned by the farmers. With the developed of GM techniques, the foods can have more nutrients and better quality. Thus, benefits the consumers.
Tuesday, June 19, 2007
Methods to Detect pathogen and toxin in Food
Methods Detect Pathogens and Toxins in Food
Antibodies are protein molecules that bind to antigens—such as bacteria—and remove them from the body. Researchers can use antibodies to isolate pathogens or chemicals in food products as well.
There is a procedure that combines immunomagnetic capture with TRF to simultaneously detect Escherichia coli and Salmonella in ground beef, ground turkey, alfalfa sprouts, and seeds. The procedure uses magnetic beads that are coated with pathogen-specific antibodies. The antibodies bind to the bacteria, and the magnetism pulls them out of complex mixtures of food. Once extracted, the bacteria can be more easily detected.
A luminescence-based method coupled with an ELISA (enzyme-linked immunosorbent assay) is to detect and confirm E. coli O157:H7. An ELISA is a sensitive laboratory test that uses antibodies and enzymes to detect and measure specific antigens in samples. The test can be completed in 8 hours and can detect 1-10 bacteria per gram of ground meat. USDA's Food Safety Inspection Service (FSIS) would ultimately like to be able to detect 1 bacterium in 25 grams of meat.
There is a biosensor immunoassay using surface plasmon resonance (SPR) to detect Staphylococcus aureus enterotoxin A (SEA) and B (SEB)-toxins that cause gastroenteritis—in foods such as ham, milk, and eggs. Conventional heating and processing kills the bacterium but not its toxins. Bacteria produce toxins under stressful conditions, such as when they are too crowded or denied food or when they're fighting back against antibiotics.
SPR uses light reflected off thin metal films. Toxin molecules in the sample bind to the sensor surface, and the refractive index at the surface changes. The time it takes for a response from the interaction provides a measure of how much toxin, if any, is actually present in the food sample.
Latex particle agglutination assay is developed for detection of SEA and SEB that causes the toxins to clump together. The method takes advantage of an antibody's ability to bind to a unique antigen in pathogen cells. The assay is simpler to use than other methods and can detect as little as 10 parts per billion of toxin per gram of sample.
Antibodies are protein molecules that bind to antigens—such as bacteria—and remove them from the body. Researchers can use antibodies to isolate pathogens or chemicals in food products as well.
There is a procedure that combines immunomagnetic capture with TRF to simultaneously detect Escherichia coli and Salmonella in ground beef, ground turkey, alfalfa sprouts, and seeds. The procedure uses magnetic beads that are coated with pathogen-specific antibodies. The antibodies bind to the bacteria, and the magnetism pulls them out of complex mixtures of food. Once extracted, the bacteria can be more easily detected.
A luminescence-based method coupled with an ELISA (enzyme-linked immunosorbent assay) is to detect and confirm E. coli O157:H7. An ELISA is a sensitive laboratory test that uses antibodies and enzymes to detect and measure specific antigens in samples. The test can be completed in 8 hours and can detect 1-10 bacteria per gram of ground meat. USDA's Food Safety Inspection Service (FSIS) would ultimately like to be able to detect 1 bacterium in 25 grams of meat.
There is a biosensor immunoassay using surface plasmon resonance (SPR) to detect Staphylococcus aureus enterotoxin A (SEA) and B (SEB)-toxins that cause gastroenteritis—in foods such as ham, milk, and eggs. Conventional heating and processing kills the bacterium but not its toxins. Bacteria produce toxins under stressful conditions, such as when they are too crowded or denied food or when they're fighting back against antibiotics.
SPR uses light reflected off thin metal films. Toxin molecules in the sample bind to the sensor surface, and the refractive index at the surface changes. The time it takes for a response from the interaction provides a measure of how much toxin, if any, is actually present in the food sample.
Latex particle agglutination assay is developed for detection of SEA and SEB that causes the toxins to clump together. The method takes advantage of an antibody's ability to bind to a unique antigen in pathogen cells. The assay is simpler to use than other methods and can detect as little as 10 parts per billion of toxin per gram of sample.
Tuesday, June 5, 2007
Roles of Local & Foreign authorities
Government Agencies and their Roles
Local- Agri-Food and Veterinary Authority (AVA): AVA adopts a science-based risk analysis and management approach based on international standards to evaluate and ensure food safety.
Food and Drug Administration (FDA): domestic and imported foods, eggs
U.S. Department of Agriculture Food Safety and Inspection Service (USDA FSIS): meat and poultry, pasteurized egg products (unshelled eggs).
1) Basically, AVA responsibility is to allow or disallow (give permission) for overseas countries companies products whether they are permitted to transport food to Singapore.
2) Check the level of additives/preservatives used in the foods, if it is over the permitted limits.
3) Responsible that the food imported and locally made by the food industry are safe to consume
by the public (Singaporean)
4) Lastly.... Local authority set the requirements and guide lines that are needed on the product (food labeling)
Local- Agri-Food and Veterinary Authority (AVA): AVA adopts a science-based risk analysis and management approach based on international standards to evaluate and ensure food safety.
Food and Drug Administration (FDA): domestic and imported foods, eggs
U.S. Department of Agriculture Food Safety and Inspection Service (USDA FSIS): meat and poultry, pasteurized egg products (unshelled eggs).
1) Basically, AVA responsibility is to allow or disallow (give permission) for overseas countries companies products whether they are permitted to transport food to Singapore.
2) Check the level of additives/preservatives used in the foods, if it is over the permitted limits.
3) Responsible that the food imported and locally made by the food industry are safe to consume
by the public (Singaporean)
4) Lastly.... Local authority set the requirements and guide lines that are needed on the product (food labeling)
Subscribe to:
Posts (Atom)