Tuesday, July 24, 2007 genetically modified foods>1stly, what are Genetically Modified (GM) foods?
Although "biotechnology" and "genetic modification" commonly are used interchangeably, GM is a special set of technologies that alter the genetic makeup of such living organisms as animals, plants, or bacteria. Biotechnology, a more general term, refers to using living organisms or their components, such as enzymes, to make products that include wine, cheese, beer, and yogurt.
Combining genes from different organisms is known as recombinant DNA technology, and the resulting organism is said to be "genetically modified," "genetically engineered," or "transgenic." GM products (current or in the pipeline) include medicines and vaccines, foods and food ingredients, feeds, and fibers.
as technology generally improves, it also brings about many kinds of causes & effects, the same applies with GM foods, it brings about many benefits & controversies..
benefits includes those of crops, animals, environment & society..
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
on the contrary, controversies of GM foods brings about safety issues, access & intellectual property, ethics, labeling & society problems..
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
What are GMOs?
Genetically modified organisms (GMOs) are life forms that have been genetically engineered. Genetic engineering (GE) is the process of taking genes from one strain of a plant, animal, or virus and inserting them into another, with the goal of reproducing characteristics of the original species in the receiving species.
GMOs could cause quite a number of unintended health impacts on humans, these includes:
Allergens. Because the addition of new genetic material changes protein sequences, the GMO could produce known or unknown allergens—especially in children.
Nutritional deficiency. Altered DNA could decrease levels of important nutrients in the GE crop.
Increased toxins. Genetic engineering could inadvertently increase naturally occurring plant toxins—or introduce a new toxic strain created by the marriage of genes.
Antibiotic resistance. An antibiotic resistant gene inserted into most GM crops may pose the most serious health hazard, since there is the possibility that these genes might transfer to pathogenic bacteria in our bodies and create new, antibiotic-resistant super-diseases.
advantages of using GM crops:
marked reduction of pesticides & insecticides usage --> due to the plants have been genetically altered to be resistant/self-detrimental to pests such as root worms, beetles & invasive parasites, thus farmer only have to use little/no pesticides to rid the fields of the pests. --> reduction of these weed killers/pests directly reduces runoff of these chemicals into groundwater & water supplies, also reduces soil pollution.
more control & precision over the characteristics of the crops/products bred, with more speed than natural processes --> higher production rates than traditional crops --> more produce in acre, with less waste
higher nutritional content in some varieties --> reduce health problems caused by dietary deficiencies
salt resistant via the over-expression of a single gene --> helps in alleviating food shortages in regions affected
reduces allergies problems worldwide -->through genetic alterations, genes that produce allergy causing substances can be removed
common types of genetically modified foods: * Corn * Tomato * Beets * Potatoes * Alfalfa Sprouts * Soy Beans * Dairy - rBGH is GE * Oils, some * Canola Oil * Tomato Sauce * Rice * Wheat * Baking Goods * Chocolate * Drinks * Meat * Poultry * Eggs * Farm Raised Fish - including Salmon
currently in the market now, there are 2 categories of genetically modified crops : namely the "insect resistant" & "herbicide tolerant"
Herbicide Tolerant crops (which include corn, cotton, soybeans, sugar beet and canola) are crops which are genetically engineered to withstand direct application of herbicides. These herbicides would kill natural crop plants, but farmers are now able to spray weed killers directly onto genetically engineered herbicide-tolerant varieties. This could mean more chemicals onto our food and in our environment. About 70% of genetically engineered crops growing in the United States today are herbicide-tolerant varieties.
Insect Resistant crops (which include corn, cotton and potatoes) are also called 'plant pesticides', because the plant itself is a pesticide. As it grows, the plant produces an insecticide, killing insects when they feed on the crop. Industry claims that these genetically engineered crops will mean that fewer chemical insecticides are sprayed. But scientists have warned that insects will develop resistance in just a few years.
Sunday, June 24, 2007 extra bites..>Difference between immunoasays & molecular biological assays:
Immunochemical assays We are creating new antibody-based tests for detection of plant and bacterial toxins in foods. Our tests are more specific than existing tests, so that scientists and first-responders can obtain more information using fewer tests.
Molecular Biological assays Foods contaminated with crude preparations of protein toxins will also contain genetic material associated with the source. We are creating new tests for sensitive detection in foods of DNA associated with pathogenic bacteria (Clostridium botulinum) and poisonous plants (Ricinus communis).
Acceptable Daily Intake (ADI)
The ADI of a chemical has been defined as the daily intake of a chemical that, during a lifetime, appears to be without appreciable risk on the basis of all the facts known at that time. The concept of the ADI is based on the assumption that a threshold exists below which a chemical does not cause toxicity.
They are usually based on experiments on the toxicity of the chemical concerned in laboratory animals, from which a lowest observable effect level (LOAEL) or no observed adverse effect level are obtained. In general, the lowest dose value is used to determine a ‘safe’ level in humans.
Acute Reference Dose (ARfD)
is the amount of a chemical that can be consumed in a single meal without causing harm. Tests conducted on laboratory animals establish an amount of pesticide (in terms of weight of pesticide per kg body weight of the animal) which will have no observable adverse effect when consumed as a single dose (the no-observed-effect-level, or NOEL).
Good Agricultural Practice (GAP)
GAP represents the conditions of pesticide use (amount, method, time of application etc) specified on pesticide labels.
Maximum Residue Levels (MRLs)
An MRL is the maximum concentration of pesticide residue (expressed in mg/kg of produce) legally permitted in or on food commodities or animal feeds. MRLs are established for specific pesticide/crop combinations.
Friday, June 15, 2007 EIA=ELISA>If you do not know, Enzyme Immunoassay (EIA) is actually a synonym for the ELISA.
ELISA, or rather known as Enzyme-Linked Immunosorbent Assay, is a rapid immunochemical test that involves an enzyme (a protein that catalyzes a biochemical reaction), an antibody or antigen (immunologic molecules). ELISA serves as a method of quantitative determination of the amount of an antibody/antigen in a biological sample.
The principle of the experiment is based on the creation and the enzymatic evidence of antigen/antibody complexes fixed to a solid phase. The end product is soluble and can be gauged spectroscopically.
ELISA tests are widely utilized to detect substances that have antigenic properties, primarily proteins (as opposed to small molecules and ions such as glucose and potassium). Substances that can be detected by ELISA tests include hormones, bacterial antigens and antibodies.
Enzyme immunoassay (EIA) is a test used to detect and quantify specific antigen-eliciting molecules involved in biological processes, specifically processes related to cancer and autoimmune disorders.
EIA can be used on most types of biological samples, such as plasma, serum, urine, and cell extracts.
- In the assay, a plate is coated with a primary antibody, which recognizes the antigen of the target molecule and bonds with it. - The antigen-antibody complex is recognized by a secondary antibody that is joined to an enzyme that catalyzes the reaction mixture, yielding a specific color. - By measuring the optical density of this color, the presence and number of a specific molecule can be determined; the density of color is proportional to the advancement of the reaction or disease being tested.
Tuesday, May 29, 2007 HACCP>HACCP = Hazard Analysis and Critical Control Point
What is HACCP? HACCP involves seven principles: - Analyze hazards. Potential hazards associated with a food and measures to control those hazards are identified. The hazard could be biological, such as a microbe; chemical, such as a toxin; or physical, such as ground glass or metal fragments.
- Identify critical control points. These are points in a food's production--from its raw state through processing and shipping to consumption by the consumer--at which the potential hazard can be controlled or eliminated. Examples are cooking, cooling, packaging, and metal detection.
- Establish preventive measures with critical limits for each control point. For a cooked food, for example, this might include setting the minimum cooking temperature and time required to ensure the elimination of any harmful microbes.
- Establish procedures to monitor the critical control points. Such procedures might include determining how and by whom cooking time and temperature should be monitored.
- Establish corrective actions to be taken when monitoring shows that a critical limit has not been met--for example, reprocessing or disposing of food if the minimum cooking temperature is not met.
- Establish procedures to verify that the system is working properly--for example, testing time-and-temperature recording devices to verify that a cooking unit is working properly.
- Establish effective recordkeeping to document the HACCP system. This would include records of hazards and their control methods, the monitoring of safety requirements and action taken to correct potential problems. Each of these principles must be backed by sound scientific knowledge: for example, published microbiological studies on time and temperature factors for controlling foodborne pathogens.
HACCP offers a number of advantages over the current system. Most importantly, HACCP: - focuses on identifying and preventing hazards from contaminating food.
- is based on sound science.
- permits more efficient and effective government oversight, primarily because the recordkeeping allows investigators to see how well a firm is complying with food safety laws over a period rather than how well it is doing on any given day.
- places responsibility for ensuring food safety appropriately on the food manufacturer or distributor.
- helps food companies compete more effectively in the world market.
- reduces barriers to international trade.
all about foodborne illness>WHAT IS FOODBORNE ILLNESS?
Foodborne illness results from eating food that is contaminated with harmful virus or bacteria such as Hepatitis A or Salmonella.Diarrhea and the resulting dehydration or loss of water may require hospitalization and can lead to temporary or permanent arthritic conditions and death in some people. Some people are more vulnerable to foodborne illness than others. The very young and the very old are generally most at risk. Other conditions which increase risk include underlying health problems, infections, pregnancy, diabetes, HIV or taking chemotherapy for cancer.
5 common ways of causes of foodborne illnesses:
- Using contaminated raw foodstuffs - Infected/ill people preparing meals - Inadequate storage combined with preparation of food several hours before consumption - Cross-contamination during food preparation - Insufficient cooking or reheating of food
Contaminated food can make you or someone else ill. When people think they have the "flu" or a "stomach bug," they may have a foodborne illness (FBI). One cannot tell from the way food looks, smells or tastes if it is safe or not, but here are ways to prevent foodborne illness.
Improper cooling or holding Cooling food too slowly is the major cause of foodborne illness. Potentially hazardous foods, such as meats, seafood, poultry and dairy products must be rapidly cooled from 140°F to 70°F within two hours, then from 70°F to 41°F within four hours. - Store food to be cooled in shallow pans no deeper than 3-4 inches
- Cool container of food in an icewater bath of half water and half ice.
- Stir the food often while cooling.
- Refrigerate hot foods uncovered in shallow pans immediately. (Use a freezer to speed it up)
- Do not place tight covers on foods during cooling.
- Allow air circulation in the refrigerator.
- Refrigerate canned foods prior to mixing it with other foods. (example: can of tuna)
- Do not cool foods at room temperature longer than 30 minutes.
Contaminated raw foods or ingredients - Certain raw foods, such as meat, fish, poultry, shellfish, milk and eggs may be contaminated with bacteria or viruses. These microorganisms can be spread during processing and preparation and can easily survive in the food if heating is inadequate.
- Buy foods from an approved source.
- Cook foods to the proper temperatures.
- Keep cold foods properly refrigerated.
- Wash all raw fruits and vegetables thoroughly.
- Avoid cross-contamination by using a separate cutting board/utensil for raw and cooked products unless they are sanitized between uses. Use a different cutting board for fruits, vegetables and breads than you do for meats.
Infected person handling foods People with poor food handling habits and poor personnel hygiene are the biggest contributors to foodborne illness outbreaks. Here is what you can do: - Do not handle food if you have colds, flu, diarrhea or hepatitis.
- Do not handle food if you have infected cuts, burns or lesions on the hands or lower arm.
- Wash hands effectively during food handling.
- Wash hands after eating, smoking, blowing nose, etc.
- Do not wipe hands or utensils on apron or cloth towels.
- Do not touch ready-to-eat foods with bare hands, if possible.
- Use utensils, deli paper, disposable gloves, etc.
- Use hand sanitizers after washing hands.
Inadequate cooking or heating of food - All potentially hazardous foods must be cooked to a safe internal temperature before consumption.
- Cook poultry, stuffing and dressing at 165°F for at least 15 seconds.
- Cook ground beef and pork products to 155°F for at least 15 seconds.
- Cook beef cuts and other foods to at least 145°F.
- Do not rely on the color of the food, but use a food thermometer to check the temperature.
Inadequate reheating Reheating leftover and refrigerated foods to improper temperatures is also a major cause of foodborne illness. Many times this happens when foods are just "warmed up" rather than heating thoroughly. Always reheat leftover refrigerated foods RAPIDLY to 165°F before serving or hot holding. If it is liquid, bring it to boil. Obtaining food from an unsafe source In all food establishments, all food received must be from an approved and inspected source. Foods processed at private homes may not be offered for sale to the public. Time lapse between food preparation and consumption Given sufficient time, bacteria in food can grow depending on the type of food, the temperature at which it was held, its moisture and its acidity level. Foods that are prepared in advance of serving must be handled very carefully. Such foods must be properly cooked, cooled to proper temperatures and stored at 41°F or below. Do not forget to reheat all leftover food to 165°F rapidly.
Friday, May 25, 2007 quick munchies about food safety>=quick faCts=
- Bacterial food-borne illness is the result of mishandling food. It includes food infection and food intoxication.
- Salmonella, Campylobacter, E. coli and Listeria bacteria in food cause food infection.
- Staphylococcus and Clostridium botulinum bacteria produce a toxin (or poison) as a by-product of growth and multiplication in food and cause food intoxication.
- Clostridium perfringens can multiply in foods to sufficient numbers to cause food poisoning.
- Sanitation and proper heating and refrigeration practices will help prevent food-borne illness.
Food intoxication results from consumption of toxins (or poisons) produced in food by bacterial growth. Toxins, not bacteria, cause illness. Toxins may not alter the appearance, odor or flavor of food. Common kinds of bacteria involved are Staphylococcus aureus and Clostridium botulinum. In the case of Clostridium perfringens, illness is caused by toxins released in the gut when large numbers of vegetative cells are eaten.
Salmonellosis Salmonellosis is a form of food infection that may result when foods containing Salmonella bacteria are consumed. Once eaten, the bacteria may continue to live and grow in the intestine, set up an infection and cause illness. The possibility and severity of the illness depends in large part on the size of the dose, the resistance of the host and the type of organism causing the illness. Salmonella bacteria thrive at temperatures between 40 and 140 degrees F. They are readily destroyed by cooking to 165 F and do not grow at refrigerator or freezer temperatures. They do survive refrigeration and freezing, however, and will begin to grow again once warmed to room temperature.
Foods commonly involved include eggs or any egg-based food, salads (such as tuna, chicken or potato), poultry, pork, processed meats, meat pies, fish, cream desserts and fillings, sandwich fillings, and milk products. These foods may be contaminated at any of the many points where the food is handled or processed from the time of slaughter or harvest until it is eaten.
Campylobacteriosis Campylobacteriosis or campylobacter enteritis is caused by consuming food or water contaminated with the bacteria Campylobacter jejuni.
C. jejuni commonly is found in the intestinal tracts of healthy animals (especially chickens) and in untreated surface water. Raw and inadequately cooked foods of animal origin and non-chlorinated water are the most common sources of human infection (e.g. raw milk, undercooked chicken, raw hamburger, raw shellfish). The organism grows best in a reduced oxygen environment, is easily killed by heat (120 F), is inhibited by acid, salt and drying, and will not multiply at temperatures below 85 F.
Preventive measures for campylobacter infections include pasteurizing milk; avoiding post-pasteurization contamination; cooking raw meat, poultry and fish; and preventing cross-contamination between raw and cooked or ready-to-eat foods.
Listeriosis Prior to the 1980s, listeriosis, the disease caused by Listeria monocytogenes, was primarily of veterinary concern.
As a result of its wide distribution in the environment, its ability to survive for long periods under adverse conditions, and its ability to grow at refrigeration temperatures, Listeria has since become recognized as an important food-borne pathogen. L. monocytogenes is frequently carried by humans and animals. The organism grows in the pH range of 5.0 to 9.5. It is salt tolerant and relatively resistant to drying, but easily destroyed by heat. (It grows between 34 F and 113 F).
Preventive measures for listeriosis include maintaining good sanitation, pasteurizing milk, avoiding post-pasteurization contamination and cooking foods thoroughly.
Staphylococcal Intoxication Staphylococcus bacteria are found on the skin and in the nose and throat of most people; people with colds and sinus infections are special carriers. Infected wounds, pimples, boils and acne are generally rich sources. Staphylococcus also are widespread in untreated water, raw milk and sewage.
When Staphylococcus get into warm food and multiply, they produce a toxin or poison that causes illness. The toxin is not detectable by taste or smell. While the bacteria itself can be killed by temperatures of 120 F, its toxin is heat resistant; therefore, it is important to keep the staph organism from growing. Keep food clean to prevent its contamination, keep it either hot (above 140 F) or cold (below 40 F) during serving time, and as quickly as possible refrigerate or freeze leftovers and foods to be served later.
Foods commonly involved in staphylococcal intoxication include protein foods such as ham, processed meats, tuna, chicken, sandwich fillings, cream fillings, potato and meat salads, custards, milk products and creamed potatoes. Foods that are handled frequently during preparation are prime targets for staphylococci contamination.
Clostridium Perfringens Food-Borne IllnessClostridium perfringens belong to the same genus as the botulinum organism. However, the disease produced by C. perfringens is not as severe as botulism. Spores are found in soil, nonpotable water, unprocessed foods and the intestinal tract of animals and humans. Meat and poultry are frequently contaminated with these spores from one or more sources during processing.
Spores of some strains are so heat resistant that they survive boiling for four or more hours. Furthermore, cooking drives off oxygen, kills competitive organisms and heat-shocks the spores, all of which promote germination.
Once the spores have germinated, a warm, moist, protein-rich environment with little or no oxygen is necessary for growth. If such conditions exist (i.e., holding meats at warm room temperature for several hours or cooling large pots of gravy or meat too slowly in the refrigerator), sufficient numbers of vegetative cells may be produced to cause illness.
E. Coli Hemorrhagic Colitis Escherichia coli belong to a family of microorganisms called coliforms. Many strains of E. ColiE. coli O157:H7, causes a distinctive and sometimes deadly disease. live peacefully in the gut, helping keep the growth of more harmful microorganisms in check. However, one strain, Ground beef is the food most associated with E. coli O157:H7 outbreaks, but other foods also have been implicated. These include raw milk, unpasteurized apple juice and cider, dry-cured salami, homemade venison jerky, sprouts, and untreated water. Infected food handlers and diapered infants with the disease likely help spread the bacteria. Preventive strategies for E. coli infections include thorough washing and other measures to reduce the presence of the microorganism on raw food, thorough cooking of raw animal products, and avoiding recontamination of cooked meat with raw meat. To be safe, cook ground meats to 160 F.
A. Freezing temperatures stop growth of bacteria, but may allow bacteria to survive. Set freezer to 0 F. B. Cold temperatures permit slow growth of some bacteria. Do not store raw meats for more than five days or poultry, fish or ground meat for more than two days in the refrigerator. C. DANGER ZONE. C-1. Some growth of food poisoning bacteria may occur. C-2. Temperatures in this zone allow rapid growth of bacteria and production of toxins by some bacteria. Do not hold foods in this zone for more than two hours. C-3. Some bacterial growth may occur. Many bacteria survive. D. Warming temperatures prevent growth but allow survival of some bacteria. E. Cooking temperatures destroy most bacteria. Time required to kill bacteria decreases as temperature increases. F. Canning temperatures for fruits, tomatoes and pickles in water-bath canner. G. Canning temperatures for low-acid vegetables, meat and poultry in pressure canner.
workload of the grp mates>phew!finally had to time to come in to blog.. in this package 1, we were better in planning and strategizing our way i doing the proj after the warming up exercise from the induction package. For package 1, our food product chosen was teriyaki chicken ramen from sakae sushi..in order to make it easier for exporting, it was therefore modified to
"Instant Teriyaki Chicken Ramen" (ITCR). we split the workload evenly, namely,
-> jing guo - soup powder (raw material) -> apple/liping - teriyaki chicken (process) -> fiona - teriyaki chicken (raw material) -> rose - soup powder (process) -> minghui - ramen (process + raw material) -> huiqi - compilation of the instant teriyaki chicken ramen
after that, we also discussed and did up the templates for the HACCP and local and overseas legislation and the concerning authorities in charge, before we made the final compilation.
For example, pertaining to the instant teriyaki chicken ramen, the critical control points to take note of will be the packaging and sealing stages, plus whether the chicken is thoroughly cooked and stored in appropriate conditions.
~ Profile ~
Apple aka Liping full time yr 3 student TA04-AA34 tp-AFSN
~ Wishes ~
muz do well for remaining assignments attached to a gd plc to work under gd ppl..
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