Immunoassays (the ELISA method)

Source obtained from: http://afic.org/Detecting%20Genetically%20Modified%20Foods%20-%20Easier%20said%20than%20done.htm

Rather than measuring the rDNA in a sample, immunoassays measure the levels of proteins expressed by DNA sequences inserted by genetic modification. The test works by using anti-bodies specific for proteins encoded by rDNA sequences. One example of a commonly used immunoassay is the Enzyme-Linked Immunosorbent Assay (or the ELISA).

The ELISA relies on a reaction between antibodies (soluble proteins that are produced by the immune system in response to a foreign substance) and a "foreign substance" (typically the inserted protein), called the "antigen". The reaction is detected by a colour change or a flourometric reaction that can be measured quantitatively.

Immunoassays are less sensitive than PCR methods, which means they are less susceptible to false positives caused by minor levels of contamination. However, careful validation of each food type is needed before the test can be performed because of the large diversity of foods. This means that new assays need to be continually developed as new products of biotechnology are developed. Many hundreds of different assays will eventually be required to enable accurate detection methods.

One of the key advantages of this method of analysis is that the results are generally available within minutes. The costs of immunoassays are also much lower than that for PCR techniques (about US$2-10 per sample) however the costs for the assay development and the generation of antibodies and protein standards mean that the up-front costs can be significant.

One problem with immunoassays is that the technique does not distinguish between different sources of biotechnology-derived rDNA that may express similar protein characteristics. For example, the technique won't detect if a specific protein, such as the Bt protein, is derived from corn or soy. In addition, proteins are denatured by many food processing methods so this technique is more useful for raw foods or food ingredients that have undergone minimal processing.

Sampling methods

The choice of technique largely depends on the type of product being analysed and the availability of equipment and funds for the analysis. Both techniques also share some common problems such as a lack of internationally recognised sampling methods or agreement on the number or size of samples required.

Enzyme immunoassay

What is Enzyme immunoassay?
Source obtained from: http://en.wikipedia.org/wiki/Enzyme_immunoassay

The Enzyme-Linked ImmunoSorbent Assay, or ELISA, is a biochemical technique used mainly in immunology to detect the presence of an antibody or an antigen in a sample. The ELISA has been used as a diagnostic tool in medicine and plant pathology, as well as a quality control check in various industries.
Performing an ELISA involves at least one antibody with specificity for a particular antigen. The sample with an unknown amount of antigen is immobilized on a solid support (usually a polystyrene microtiter plate) either non-specifically (via adsorption to the surface) or specifically (via capture by another antibody specific to the same antigen, in a "sandwich" ELISA). After the antigen is immobilized the detection antibody is added, forming a complex with the antigen. The detection antibody can be covalently linked to an enzyme, or can itself be detected by a secondary antibody which is linked to an enzyme through bioconjugation. Between each step the plate is typically washed with a mild detergent solution to remove any proteins or antibodies that are not specifically bound. After the final wash step the plate is developed by adding an enzymatic substrate to produce a visible signal, which indicates the quantity of antigen in the sample. Older ELISAs utilize chromogenic substrates, though newer assays employ fluorogenic substrates with much higher sensitivity. In simple terms, an unknown amount of antigen in a sample is immobilized on a surface. One then washes a particular antibody over the surface. This antibody is linked to an enzyme that visibly reacts when activated, say by light hitting it in the case of a fluorescent enzyme; the brightness of the fluorescence would then tell you how much antigen is in your sample.

Identification of Foodborne Bacterial Pathogens

Identification of Foodborne Bacterial Pathogens by Gene Probes
Source obtained from: http://www.cfsan.fda.gov/~ebam/bam-24.html

The above website contains information on:

• Some gene probes used to detect pathogenic bacteria in foods
• Description of individual probes to identify targets.

Example of Probes and their targets:

Campylobacter jejuni: Ribosomal RNA
A probe that is specific for C. jejuni ribosomal RNA genes has been developed (86,87) and is available commercially. A pool of randomly selected and tested chromosomal fragments is also specific for C. jejuni, but the target has not been reported (83).

Escherichia coli: Heat-labile enterotoxin genes
The heat-labile enterotoxins (LT) of E. coli are a closely related group of proteins; they are distinguished from heat-stable enterotoxins (ST) by being immunogenic and are inactivated by heating at 60°C for 10 Min (31). The toxins stimulate adenylate cyclase (30) and can be detected by tissue culture assays of Chinese hamster ovary cells (30) or mouse Y-l adrenal cells (13). Using these tests, So et al. (102) localized and cloned the structural gene for LT; Dallas et al. (8) recloned a smaller fragment into plasmid pEWD299. Although there are several different genes for LT, as evidenced by their nucleotide sequences (56,73,103,110,111), they all share a significant amount of genetic similarity. The region of the LT genes chosen as a gene probe target is identical in each of these genes, so that all strains with the genetic potential to produce LTs should be detected.
The LT probe, eltA11, is a 20 base synthetic oligonucleotide that encodes amino acids 45-51 of the A subunit of the E. coli LT (111).

Methods

Four different techniques can be used for colony hybridization tests:

1. Direct plating of samples for enumeration.
2. Direct plating of cultures after enrichment to determine presence/absence.
3. Spotting of individual colonies or pure cultures for an additional hybridization assay to confirm a positive result from colony hybridization with a mixed culture.
4. Returning to a "master" replica plate to make pure cultures of positive colonies for further study and analysis.

The first three techniques differ as to when solid media are inoculated. In the first, aliquots of the homogenized sample are plated immediately after blending. In the second, plates are inoculated after aliquots of the homogenized sample have been incubated under selective conditions. Samples from the first and second techniques are plated onto selective agar media whenever such appropriate media are available. For the third technique, individual positive colonies are re-streaked and an additional colony hybridization test is conducted to ensure that the initial positive or negative results can be repeated. With the last technique, a pure culture can be obtained without selective enrichment, and additional microbiological tests requiring a pure culture can then be performed.

Control cultures
Strains that are positive or negative for the various probe tests must be properly stored and periodically tested for the appropriate phenotypic characteristics. A test methodology other than a gene probe must be used to independently verify the genotype of the control microorganisms. Control cultures must also be stored appropriately to minimize the possibility of genetic change. Usually, freezing liquid cultures at -70°C in 10-25% glycerol will suffice, except for Vibrio species, which are particularly sensitive to cold. Appropriate control strains have been listed, but other strains can be used if they have been properly characterized.

DNA PROBES

What are DNA Probes?
Source obtained from: http://en.wikipedia.org/wiki/DNA_probe

In molecular biology, a hybridization probe is a fragment of DNA of variable length (usually 100-1000 bases long), which is used to detect in DNA or RNA samples the presence of nucleotide sequences that are complementary to the sequence in the probe. The hybridization probe is labeled radioactively (commonly with 32P) or with immunological markers, such digoxigenin. The labeled probe is then denatured (by heating) into single DNA strands and hybridized to target DNA (Southern blotting) or RNA (northern blotting) immobilized on a membrane or in situ. DNA sequences or RNA transcripts that have moderate to high (depending on the stringency in the hybridization) sequence similarity to the probe, are detected by visualizing the hybridized probe via autoradiography or other imaging techniques. Hybridization probes used in DNA microarrays refer to DNA covalently attached to an inert surface, such as coated glass slides or gene chips, and to which a mobile DNA target is hybridized.

Bacillus thuringiensis (Bt)

What is Bt?

Bt is the abbreviated name given to the common bacterium Bacillus thuringiensis. Different strains of this bacterium produce a range of different crystal proteins that are toxic to different types of insects. Most are only toxic to Lepidopterans (butterflies and moths), Coleopterans (beetles) or Dipterans (flies) but some are toxic to more than one of these insect groups.
These crystal proteins are not toxic to any other insects or living organisms, including humans.
Bt has a long history of safe use as a natural insecticide that is used widely by the organic
food industry and in many developing countries to protect agricultural and forestry crops from insect pests. It has probably always been present (in trace amounts) in the human diet due to its common presence in soil and water and on the surfaces of plants.
Genes coding for Bt crystal proteins have recently been introduced into GM plants to protect them from insect attack.
The toxic effect of the Bt crystal proteins requires a particular gut environment and special gut receptors that are only present in some insects.The crystal proteins must be eaten by the insect larvae and converted into a toxic form by enzymes in the insect gut.The toxic protein then binds to specific receptors on the insect gut wall, leading to death of the cells lining the gut wall and paralysis of the gut. The insect stops feeding and dies.
A large number of scientific studies have shown that Bt is not toxic to humans or other
vertebrate animals. Rats, mice, rhesus monkeys and humans do not contain receptors for the toxin proteins.
There are several environmental concerns associated with the use of Bt in agriculture—
such as the possibility of toxic effects on beneficial insect populations and the possibility
that insects will become resistant to the action of Bt.These concerns are addressed by other government agencies before GM crops are allowed to be grown.

Toxins in GM Foods

Source obtained from: http://www.foodstandards.gov.au/_srcfiles/GM%20Foods_text_pp_final.pdf

What about toxins in GM foods?
All substances — both natural and human-made — are toxic at some dose. However, substances classed as toxins are those that can be harmful to health at typical levels of exposure. A number of different toxins are found naturally in various foods, but the vast majority of these are present at concentrations well below the level that would harm the consumer.

Examples of toxic substances found in foods include:

• glycoalkaloids found in green potatoes
• fungal toxins that sometimes contaminate food
• glucosinolates in cabbage, cauliflower, broccoli, brussels sprouts and canola
• erucic acid in canola
• psoralens in celery
• cyanogenic glycosides in bitter almonds
• substances in poisonous species of fish and mushrooms.

Thus, toxic substances are naturally present in many conventional foods that are subsequently genetically modified. For example, both GM and conventional varieties of canola naturally contain erucic acid, and there is a limit on the amount of erucic acid that is allowed in foods derived from canola, such as canola oil. These limits apply whether the food is derived from conventional or GM
canola.
Unless any toxins present in a conventional food are specifically removed, they will remain in the GM version of the food. FSANZ compares the levels of naturally occurring toxins in the conventional food with those in the GM food. If a safety assessment found that levels of naturally occurring toxins were
higher in a GM food, FSANZ would need to assess how much of the food is normally eaten (that is, the dietary intake), to ensure that the levels of toxins consumed would not be harmful to health.

Genetic Modification

Source obtained from: http://www.gurupedia.com/g/gm/gmo.htm#Genetic_modification_of_bacteria

Genetic Modification of Bacteria

Three processes are known by which the genetic composition of bacteria can be altered: transformation, conjugation and transduction.

• Transformation is a process by which some bacteria are naturally capable of taking up DNA to acquire new genetic traits. This phenomenon was discovered by Fred Griffith in 1928, although the fact that it was specifically DNA molecules that carried the genetic information was not proven until 1944. Bacteria that are competent to undergo transformation are frequently used in molecular biology.
• In conjugation, DNA is transferred from one bacteria to another via a temporary connecting strand of DNA called a pilus (a process analogous to but biologically distinct from mating). Conjugation is not widely used for the artificial genetic modification of bacteria.
• Transduction refers to the introduction of new DNA into a bacterial cell by a bacteriophage (a virus that infects bacteria).

Genetic Modification of plants

The principle technique for the genetic modification of plants is based on a natural ability of the bacteria Agrobacterium tumefaciens. This bacteria infects plants and causes a tumor-like growth termed a crown gall. Agrobacterium causing crown galls contains a plasmid (a circular piece of DNA) that transfers from the bacteria into the infected plant and integrates into the plant's genome. The transferred genes cause the plant to form the gall, which houses the bacteria and produces nutrients that support the bacteria's growth. A number of scientists contributed to this discovery throughout the late 1960s and the 1970s, with key discoveries by Jeff Schell, Marc Van Montagu, Georges Morel and Jacques Tempé. By 1983 biotechnology had reached the point where it was possible to insert additional genes of interest into Agrobacterium and thus transfer those genes into plants.

Genetic Modification of animals

Like bacteria and plants, animals can be genetically modified by viral infection. However, the genetic modification occurs only in those cells that become infected, and in most cases these cells are eventually eliminated by the immune system. In some cases it is possible to use the gene-transferring ability of viruses for gene therapy, i.e. to correct diseases caused by defective genes by supplying a normal copy of the genes. Permanent genetic modification of whole animals can be accomplished in mice. The process begins by first genetically modifiying a mouse embryonic stem cell. This is normally done by physically introducing into the cell a plasmid that can integrate into the genome by homologous recombination. This altered cell is implanted into a blastocyst (an early embryo), which is then implanted into the uterus of a female mouse. A pup born from this blastocyst will be a chimera containing some cells derived from the unmodified cells of the blastocyst and some derived from the modified stem cell. By selecting mice whose germ cells (sperm or egg producing cells) developed from the modified cell and interbreeding them, pups that contain the genetic modification in all of their cells will be born.

Continuation on set-backs of producing GM Foods

Source obtained from: http://www.idebate.org/event_documents/3c959b698e.doc

• Immune resistance – the more organic materials' genetic makeup are tampered with, the more likely human immunity is weakened
• Intrusion into the delicate balance of ecosystems – which may threaten biodiversity
• Toxin transfer – genetically modified organisms (GMOs) lower immune resistance in animals which may transmit toxins into groundwater that, in turn, passes disease onto humans
• Trade disputes – companies and/or countries who dominate the technology of GM foods risk conflicts and trade wars between nations
• Dependency – GM foods risk the dependence of developing nations on industrialized nations, via the companies from industrialized countries

Genetically Modification of Foods

What is genetic modification of foods

• Plants

Source obtained from: http://carroll1.cc.edu/~fys/ppp/pros.htm

Pesticides and Insecticides Reduction
The use of genetically altered crops can help reduce the pollution due to the use of harmful pesticides and insecticides. Certain crops can be genetically altered so that they have an insecticide or pesticide already built into them. These plants will deter insects and resist fungus with the minimum use of chemicals. This in turn means that less of these chemicals will make it into our drinking water, lakes, rivers and streams. By using these plants we will also lessen the chance of other animals being harmed. The insecticides and pesticides that are used can affect many populations of animals. It can sometimes act as a poison for many birds and small animals. The chemicals also can harm the fish in the surrounding rivers and lakes. The genetically altered plants allow us to use less chemicals and prevent hurting many animals.
Crops can also be genetically altered for herbicide resistance. This allows farmers to use less hazardous and more short-term herbicides. It also reduces the need for tilling the soil. This in turn reduces soil erosion.

Benefits of Genetically Modifying Plants

• Pesticide/Insecticide Reduction
• Medical Applications
• GM Plants will be Tastier and Healthier
• Disease Resistant Plants
• Help World Hunger
• Nutritional Value

Benefits and the set-backs of Producing GM foods

Benefits in GM Foods
Source pbtained from:http://www.foothilltech.org/9th-grade-action-based-project/health-care/genetically_modified_foods-1984.htm

The first and foremost issue is, what are the benefits of the use of genetically modified organisms (GMO) in food products. Humans are not the only beneficiaries of GM foods; there are benefits for crops, animals and society as a whole. Genetic engineering may enhance the taste and quality of food products. It reduces that maturation time and increases nutrients found in the food. Genetic engineering improves resistance to disease, pests and herbicides and increases yields and stress tolerance. Biotechnology companies have rushed to produce characteristics such as resistance to drought, disease and insects in food crops that previously did not have them. Many new crops require less processing in the factories and fewer additives. Because they have genes that make them last longer, there is less wastage. Another possible benefit is the reduced use of pesticides, fertilizers and energy compared to conventional farming methods. Farmers do not need to till the soil, lessening soil erosion and reducing labor and machinery. Animals reap the benefits of GM foods – they have an increased resistance, productivity, and hardiness. They give better yields of meat, eggs and milk. Their health is also improved through the consumption of this food. Moreover, genetic engineering not only produces advanced crop products, it benefits the environment as a whole. Genetic engineering produces friendly bioherbicides and bioinsecticides. It provides for better natural waste management and helps conserve soil, water and energy. Additionally, one of the most important benefits of GM foods is the increased food security for growing populations. Gm foods offer greater yields and more resistance to pests and viruses which in turn assure the growing population that there will be enough food to eat.

Set-backs of producing GM foods
Consumers are often not aware that they are consuming GMOs, as the Federal Drug Administration (FDA) has not yet made labeling of GMOs in food a requirement. There is continued research and more products are found to contain GMOs. GM foods are unlabelled and are everywhere. The possibilities of human allergies to these organisms or chemicals is a risk that some members of society do not wish to take yet they have no choice as they are not aware which foods contain the GMO. GM food could be a serious risk to human health. Proteins made from the foreign genes might be directly toxic to humans. The genes could alter the functioning of a plant in ways that make its food component less nutritious or more prone to carrying elevated levels of the natural poisons that many plants contain in small amounts that could be toxic to humans.

The following is another of my research for the benefits and the set-backs of producing GM Foods in point form.

Source obtained from: http://www.ornl.gov/sci/techresources/Human_Genome/elsi/gmfood.shtml

Benefits

Crops

• Enhanced taste and quality
• Reduced maturation time
• Increased nutrients, yields, and stress tolerance
• Improved resistance to disease, pests, and herbicides
• New products and growing techniques

Animals

• Increased resistance, productivity, hardiness, and feed efficiency
• Better yields of meat, eggs, and milk
• Improved animal health and diagnostic methods
  

Environment

• "Friendly" bioherbicides and bioinsecticides
• Conservation of soil, water, and energy
• Bioprocessing for forestry products
• Better natural waste management
• More efficient processing
  

Society

• Increased food security for growing populations

Controversies

Safety

• Potential human health impact: allergens, transfer of antibiotic resistance markers, unknown effects Potential environmental impact: unintended transfer of transgenes through cross-pollination, unknown effects on other organisms (e.g., soil microbes), and loss of flora and fauna biodiversity

Access and Intellectual Property

• Domination of world food production by a few companies
• Increasing dependence on Industralized nations by developing countries
• Biopiracy—foreign exploitation of natural resources

Ethics

• Violation of natural organisms' intrinsic values
• Tampering with nature by mixing genes among species
• Objections to consuming animal genes in plants and vice versa
• Stress for animal

Labeling

• Not mandatory in some countries (e.g., United States)
• Mixing GM crops with non-GM confounds labeling attempts

Society

• New advances may be skewed to interests of rich countries

Genetically Modified Foods

What is Genetically Modified Foods (GM Foods)?
Source Obtained from: http://www.gm.org/
A genetically modified food is a food product derived in whole or part from a genetically modified organism (GMO) such as a crop plant, animal or microbe such as yeast.

Source Obtained from:http://en.wikipedia.org/wiki/GM_food
Genetically Modified (GM) foods are produced from genetically modified organisms (GMO) which have had their genome altered through genetic engineering techniques. The general principle of producing a GMO is to insert DNA that has been taken from another organism and modified in the laboratory into an organism's genome to produce both new and useful traits or phenotypes. Typically this is done using DNA from certain types of bacteria. GM Foods have been available since the 1990s, with the principal ones being derived from plants; soybean, corn, canola and cotton seed oil.

Modified Atmosphere Packaging

Source obtained from:

http://en.wikipedia.org/wiki/Modified_atmosphere

Modified atmosphere is a common technical definition that describes the practice of modifying the composition of the internal atmosphere of a package (commonly food packages, but this technique is also used for drugs) in order to improve the shelf life.
The modification process often tries to lower the amount of oxygen (O2), moving it from 20% to 0%, in order to slow down the growth of aerobic lifeforms and the speed of oxidation reactions. The removed oxygen can be replaced with nitrogen (N2), commonly acknowledged as an inert gas, or carbon dioxide (CO2), which can lower the pH or inhibit the growth of bacteria.

Gases used in MAP
•CO2 – bacteriostatic and fungistatic properties; inhibits growth of spoilage bacteria
•O2 – normally excluded or set at low concentration because it promotes for eg, fat oxidation
•N2 – counteract package collapse caused by CO2 dissolving in food
- retards growth of aerobic spoilage by microbes
MAP is associated with chilled temperature. Eg, mooncake pastry is chilled to
prevent water loss
• MAP maintains high relative humidity and reduction in water loss

Foodborne Illnesses

What are foodborne illnesses?

Foodborne illnesses are caused by the consumption of contaminated foods or beverages. Such contamination usually arises from improper handling, preparation, or food storage. Therefore, good hygiene practices should be practiced before, during, and after food preparation can reduce the chances of contracting an illness.
There are many kinds of foodborne illnesses which are usually caused by different bacteria or other pathogens on food. They can affect a person by displaying many flu-like symptoms such as nausea, vomiting, diarrhoea or fever. Pathogens refers to bacteria that cause disease or an illness. When certain pathogens enter food, they can cause serious foodborne illnesses, which may be fatal.

What are some common foodborne illnesses found in Meat and Poultry
Source obtained from: http://www.fsis.usda.gov/OA/haccp/higuide.PDF

Campylobacter

Disease and symptoms:

• Causes diarrhea 2-7 days after eating contaminated food
• May cause nerve damage 1-6 weeks after infection.

Source:

• Fecal contamination of raw poultry and meat.

Transmission:

• Cross contamination from raw meat
• Poultry drippings
• Consumption of undercooked food.

Characteristics of Campylobacter:

• Sensitive to heat and drying.
• Grows in reduced oxygen environments.
• Grows at human body temperature.
• Does not grow in acid food.
• Survives but does not grow during refrigeration and freezing.

Clostridium botulinum

Disease and symptoms:

• Blurred or double vision,
• Dry mouth, difficulty swallowing,
• Paralysis of respiratory muscles.
• Vomiting and diarrhea may be present.

Source:

• Soil and the intestinal tract of animals.

Transmission:

• Consumption of toxin that has been formed in food by Clostridium botulinum.

Characteristics of Clostridium botulinum:

• Toxin is destroyed by high heat
• Bacteria can grow in most low-acid foods under low oxygen conditions.
• Bacteria grow best without oxygen.
• High acid (pH 4.6) prevents the occurrence of toxin production.

Clostridium perfringens

Disease and symptoms:

• Diarrhoea 6-24 hours after eating contaminated food.
• Abdominal pain 6-24 hours after eating contaminated food.

Source:

• Intestinal tract of healthy persons and animals.

Transmission:

• Usually exists in inadequately heated or reheated meats.

Characteristics of Clostridium perfringens:

• Has a heat resistant form known as a spore.
• Spores survive normal cooking procedures, including boiling.
• Grows well without oxygen.
• Bacteria grow best at 110-120°F.
• Slow cooling and non-refrigerated storage of cooked meat and poultry permit growth of bacteria to high numbers.

Escherichia coli

Disease and symptoms:

• Causes diarrhoea, which may be bloody
• Occasional fever.
• May result in kidney failure and death, especially in children.

Source:

• Fecal contamination of beef.

Transmission:

• Consumption of raw or undercooked hamburger, contaminated produce, such as sprouts, unpasteurized milk, and juices.

Characteristics:

• Killed by mild heat.
• Grows with or without air. Optimum temperature for growth is human body temperature.
• Grows in moist, low-acid foods.

Salmonella

Disease and symptoms:

• Causes acute diarrhoea
• Vomiting and abdominal pain
• Fever.
• Occasionally, may cause blood stream infections
• Death.

Source:

• Fecal contamination of meat and poultry.

Transmission:

• Primarily from consumption of raw or undercooked eggs, milk, meat and poultry.

Characteristics:

• Killed by mild heat.
• Grows with or without air. Grows best at human body temperature, which is around 37oC.
• Grows very poorly at refrigeration temperatures and does not grow above 130°F.
• Does not grow well or at all in acidic foods.
• Survives well in frozen or dry foods. Bacteria in dry foods are more resistant to heat.

Staphylococcus aureus

Disease and symptoms:

• Vomiting and nausea
• Abdominal cramps
• Diarrhoea

Source:

• May be present on raw meat and poultry but contamination of food is primarily from humans.

Transmission:

• Bacteria multiply in food products to high levels and produce a heat stable toxin.

Characteristics:

• Bacteria killed by mild heat, however
• Toxins are very heat stable, and will withstand thermal processing for prolonged periods.
• Bacteria grow with or without air at body temperatures.
• Toxin not usually produced in acid food.
• Bacteria resistant to high salt (up to 15%).

Listeria monocytogenes

Disease and symptoms:

• Meningitis, which is sudden fever, intense headache, nausea, vomiting and coma).
• Flu-like illness
• Diarrhoea.

Source:

• Post-heat-processing contamination from the plant environment including plant personnel, equipment, floors, walls, drains, condensation from coolers, etc.

Transmission:

• Consumption of contaminated processed ready-to-eat meats.
• Vegetables
• Unpasteurized dairy products.

Characteristics:

• Killed by pasteurization temperatures.
• Grows with or without air (prefers reduced oxygen conditions)
• Able to grow at refrigeration temperatures and high salt concentration.
• Withstands repeated freezing and thawing.
• Survives for prolonged periods in dry conditions.

Hawaiian Pizza

Hawaiian pizza recipe
source obtained from: http://www.culinarycafe.com/Pizza/Basic_Pizza_Crust.html

Ingredients:
1 tablespoon dry yeast
1/2 teaspoon sugar
2 2/3 cups warm water
2 tablespoons olive oil
7 1/2 cups unbleached all-purpose flour
1/4 cup whole-wheat or rye flour
1 tablespoon coarse salt or 2 teaspoons fine salt

source obtanied from: http://www.fabulousfoods.com/recipes/breads/yeast/pizzadough.html

By Food Processor:

• Pour in warm water. The water should be about 85 to 115° F.
• Add the honey and salt. Mix on low for about 20 seconds.
• Add the yeast and mix on low for another 5 seconds.
• Add 1 cup of flour, mix on low for 10 seconds.
• Add the olive oil and mix until blended (about 15 or 20 seconds more).
• Add the rest of the flour (and any othr additions) and mix on high for about a minute or two. The dough should turn into a ball and roll around the processor. (If the dough does not ball up because it's too dry, add water one tablespoon at a time until it does. If your mixture is more like a batter, add flour one tablespoon at a time. Adding water or flour as needed to get the right consistency will assure you always get a perfect dough.)
• Once the dough is balled up, place the ball on a floured board and knead for about a minute. This builds the gluten which helps the dough to rise and become fluffy when cooked.
• Place the dough in a plastic grocery bag or a covered bowl and store in a warm, dry area to rise.
• After about 45 minutes the dough should have about doubled in size.
• Punch the dough down, so it deflates.
• Let it rise for another hour to an hour and a half. The dough is now ready to be rolled out.

Product Recall

What is product recall?
Source obtained from: http://en.wikipedia.org/wiki/Product_recall
http://www.recalls.gov.au/recall.pdf

• A product recall is a request to return to the maker or producer, a batch or an entire production run of a product having in mind the best interest of suppliers and consumers to make sure that unsafe consumer products are effectively removed from the marketplace.
• Recalls are costly to a company because they often entail replacing the recalled product or paying for damages caused in use, albeit possibly less costly than indirect cost following damages to brand name and reduced trust in the manufacturer.

Some of the general steps of product recall

• Maker or dealer notifies the authorities responsible of their intention to recall a product. Consumer hotlines or other communication channels are established. The scope of the recall, that is, which serial numbers or batch numbers etc. are recalled, is often specified.
• Product recall announcements are released on the respective government agency's website (if applicable), as well as in paid notices in the metropolitan daily newspaper. In some circumstances, heightened publicity will also result in news television reports advising of the recall.
• When a consumer group learns of a recall it will also notify the public by various means.
• Typically, the consumer is advised to return the goods, regardless of condition, to the seller for a full refund or modification.
• Avenues for possible consumer compensation will vary depending on the specific laws governing consumer trade protection and the cause of recall.

Aims of product recall

• Minimise the risk of injury or death to consumers by removing an unsafe product from use
• Minimise the cost and inconvenience to consumers and the company

When to recall?

• A recall is done as soon as one becomes aware of a possible defect in a product that
  may make it unsafe.

Food Safety

What is food safety?
Source obtained from: http://www.emro.who.int/Publications/EMHJ/1006/PDF/13%20Food%20safety.pdf

• For consumers, the definaition of food safety is generally quite practical and simple. Some will have ideas as simple as, so long as the food eaten does not cause a person to fall sick, it is considered safe. While others may describe safe food as food that is within its shelf life and has been stored or distributed at the proper temperature. Some other consumers may food that is not "contaminated" as safe to consume food.
  
• However, for the food industry, it defines food safety by its specification for raw materials and finished products. For example, acceptable limits for chemical hazards, like pesticide, physical hazards such as metal fragments, and microbiological hazards such as Salmonella.
  
• The World Health Organization (WHO) and Food and Agriculture Organization (FAO), on the other hand, define food safety as food that is free from all hazards, whether chronic or acute, that may make food injurious to the health of the consumer. Also, measures and conditions that are necessary during the receiving, production, processing, storage, distribution and preparation of all kinds of food to ensure that it is safe, wholesome and fit for human consumption.
  
  Food Safety Tips

At home:

• Do not handle raw and cooked food with the same pair of utensils
• Refrigerate or freeze perishable food within 2 hours of shopping or preparing.
• Wash hands, cutting boards, dishes, utensils, and work surfaces frequently with hot,
  soapy water.
• Keep hot food above 60 degrees celcius and cold food below 5 degrees celcius.
• Never partially cook food for finishing later because you increase the risk of bacterial
  growth.
• Use a food thermometer to check the internal temperature of food such as meat, poultry. Check temperature in several places to be sure food is safely cooked.

Avian Flu Virus

What is Avian Flu Virus?
Source obtained from: http://www.who.int/mediacentre/factsheets/avian_influenza/en

• Avian influenza is an infectious disease of birds caused by type A strains of the influenza virus.

Presence and survival of the virus

Source obtained from: http://www.fmi.org/foodsafety/WHO_Food_Safety_Issues.pdf

• Avian influenza viruses survive in contaminated raw poultry meat and therefore can be spread through the marketing and distribution of contaminated food products, such as fresh or frozen meat. In general, low temperatures maintain the viability of the avian influenza virus.
  
• The virus can survive in faeces for at least 35 days at low temperature (4°C), while at 37°C, viruses could survive for 6 days.
  
• However, normal cooking (temperatures at or above 70°C in all parts of the product) will inactivate the virus.

What are some safety issues related to Avian Flu Virus?

Source obtained from: http://www.fmi.org/foodsafety/WHO_Food_Safety_Issues.pdf

• Conventional cooking (temperatures at or above 70°C in all parts of a food item) will inactivate the H5N1 virus. Properly cooked poultry meat is therefore safe to consume.

• Eggs can contain H5N1 virus both on the outside (shell) and the inside (whites and yolk). Eggs from areas with H5N1 outbreaks in poultry should not be consumed raw or partially cooked (runny yolk); uncooked eggs should not be used in foods that will not be cooked, baked or heat-treated in other ways.

• There is no epidemiological evidence to indicate that people have been infected with the H5N1 virus following consumption of properly cooked poultry or eggs.

• The greatest risk of exposure to the virus is through the handling and slaughter of live infected poultry. Good hygiene practices are essential during slaughter and post- slaughter handling to prevent exposure via raw poultry meat or cross contamination from poultry to other foods, food preparation surfaces or equipment.