Lab report on visit to agri food

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The number of food-borne disease causes/outbreaks has been constantly increasing throughout recent years. Every year, there are approximately 1.5 billion cases of food-borne disease cases reported, which results in about 3 million deaths per year (Agri-Food Veterinary Authority of Singapore, 2010).

Singapore is a country, scarce of land. Therefore, utilizing the limited land for economical and housing districts is an upmost priority as compared to using the land for agriculture. This results in Singapore importing about 90% of its total food consumption from other countries. Thus, any disruption in supply from any soruce can have a servere impact on our food supply .To minimise the risk of being vulnerable to sudden food crisis, Singapore chooses to obtain its food from many different countries. This may involve facilitating overseas investments in production of food, and also passing on farming technology and laboratory services to the region. Despite these efforts, different countries will still have different acceptance benchmarks for the compounds in food. Therefore, it is necessary for Singapore to ensure that imported food is being evaluated according to the same guidelines so as to ensure that the food is safe for consumption.

In 1959, Singapore saw a need for a division "to provide a coordinated approach to developing and regulating the local farming and fishing industry." (Agri-Food Veterinary Authority of Singapore, 2010.) Thus, the Primary Production Department (PPD) was formed through the merger of the Agriculture, Veterinary, Co-operative, Fisheries and Rural Division. From 1960 - 2000, PPD's role went through major changes as Singapore's farming activities diminished. Thus, PPD took on additional functions in terms of testing for the safety of food and facilitating agri-trade. Due to these changes, PPD was renamed Agri-Food & Veterinary Authority (AVA).

Today, the AVA has put in place an integrated food safety system to keep food safe for our consumption. This is an effective method as it is proven that Singapore enjoys one of the lowest incidences of food-borne disease outbreaks as compared to the rest of the world. (Agri-Food Veterinary Authority of Singapore, 2010.) The major role of the AVA, simply put, is to perform tests to ensure food safety. Every day, numerous tests are conducted within the AVA's laboratory facilities. These test types range from chemistry to microbiology. Such tests also allow AVA to detect any unconformities, such as the presence of toxins and microbes that pose a threat to public health. Despite the large number of tests that the AVA have to go through each day, these test results have to be released quickly, usually within 2 days for poultry and ½ a day for vegetables. This is to prevent incurring extra costs for storage and keeping the food fresh. Microbiology, Toxins, Contaminants and Nutrition Laboratories are the key laboratory departments in AVA. A brief flow of the work process is depicted in figure 1 below.

Figure 1

The necessity to check on food before marketing it to consumers

It is necessary to perform checks on food imported into Singapore. Imported food might contain contaminants such as microbes, harmful chemicals and toxins that may cause diseases, food poisoning and food spoilage. Thus, these tests are very important and without stringent testing, the public's health and safety will be put at risk. The AVA also has the ability to prevent major food-borne disease outbreaks. A very good example would be preventing imported milk powder mixed with melamine from entering Singapore.

Nevertheless, there is no system that is foolproof. AVA is unable to conduct tests on every single imported food item that enters Singapore. For new or high risk consignments imported into Singapore, 100% testing is being done for 3 rounds. After which, if the imported consignments passes all 3 rounds, AVA will then reduce the frequency of testing to 1 test in every 20 consignments imported. However, this does not mean that AVA is less stringent on consignments that have passed the 100% testing. If there is any news or reports concerning a food-borne disease outbreak caused by a particular consignment, or that if a particular consignment fails a test, AVA will revert to testing 100% of the consignments.

Different Laboratories in AVA

In AVA, there are a total of 9 different laboratory departments testing for different compounds/microorganisms found in food. They test for:

Chemical contaminants

Nutritional components, food additives and preservatives

Drug residues

Pesticide residues

Food microbiology

Foodborne parasites

Food physical quality

Foodborne toxins

Molecular biology and Genetically Modified Organisms (GMO) analysis.

More details regarding 3 of the 9 departments will be discussed.

Microbiology Laboratory

For safety purposes, microbiological tests are performed on water, fresh or processed meat, fish, dairy and other primary produces. Rapid methods are used and many automated procedures reduce the time needed for detection, identification and enumeration of foodborne pathogens. Common pathogenic species tested are Salmonella, Shigella, Vibrios, Yersinia, Clostridium, Campylobacter, Listeria, Escherichia coli O157:H7 and Vancomycin Resistant Enterococci.

AVA will receive batches of food required for food testing. These foods may either be considered as high risk foods or it can be that a particular company does not have a strong history of food safety. Upon receiving these samples, they are processed before being plated. The plating is done by a Spiral Auto-plating system which plates samples onto the agar plates in approximately 7 seconds. This helps increase efficiency, and allows AVA to process high amounts of samples. Thereafter, an automated total plate count machine is used to count the total number of bacteria colonies grown on an agar plate (enumeration stage). Automated machines are used because they have the ability to speed up the counting process. An automated counter can quickly and accurately process more than 500 plates an hour. This is 10 times more than the 50 plates if counting is done manually.

Immediately after plate counting, the sample is sent for bacterial identification by scanning the different pathogens. They use automated Polymerase Chain Reaction (PCR) machines to detect these pathogens. These automated PCR machines will relatively quickly show the results of the samples on a computer screen. A green light is indicative of a negative result while a red light would be indicative of a positive result.

To ensure that the tests are accurate, the samples which test for positive are sent to a machine called VITREK 2 - COMPACT. This machine further identifies and detects pathogens, and classifies them according to the following groupings - Gram Negative (GN); Gram Positive (GP); Bacillus (BCC); Yeast (YST); Neisseria (NH) and Anaerobes (AN).

Based on the test results, AVA will grant a pass or fail to a particular consignment. Failing a consignment has its consequences as the food importer or exporting country can challenge AVA's results and demand for a report. Therefore, AVA has to be very careful and ensure that all evidences of the tests conducted are kept. AVA uses freeze drying and cryopreservation techniques to preserve the pathogen samples in cases of dispute from food importers and exporting countries.

Food-borne Toxins Laboratory

AVA screens and detects toxins in food and animal feed. Not only are the tests done on imported food, AVA also does tests and provides export health certifications for local farms that export products overseas. For example, AVA does regular checks on the oysters, mussels and surrounding waters of the Singapore oyster and mussel farms. Besides these products, Singapore also exports a substantial amount of swordfish and tuna to other countries. Thus, it is important to test for any possible toxins before exporting, so as to safe guard the exporters and consumers. Sensitive and rapid methods are used to analyze food borne toxins. Some of the common toxins tested are:

Mycotoxins, which include aflatoxins B and G in feed, cereals, grains and nuts, aflatoxin M in milk and dairy products, Patulin in apple juice, citrinin in fermented red yeast, rice and barley, fumonisin B1 and B2 in maise and feed, deoxynivalenol in cereal maise and flour, and Ochratoxins A in coffee beans, cereal, dried foods and beer.

Marine biotoxins produced by toxigenic strains of algae (Red Tide), can accumulate in fish and shellfish. These toxins include Paralytic Shellfish Poison (saxitoxin), Diarrhetic Shellfish Poison (Okadaic acid), and Amnesic Shellfish Poison (Domoic acid).

Bacterial toxins produced by Staphylococcus aureus and Bacillus cereus in food.

Other natural toxicants or allergens such as histamine in scombroid fish.

How foods such as fish are examined

Different parts of the fish are used to look out for possible toxins. For instance, the flesh of the fish is used in the examination of histamine. Fats will be used to test for pesticide levels and the urine, eyeballs and meat of the fish can be used to test for drug residues. One such example is the testing of tuna fishes by AVA, for histamine before exportation to other countries such as the USA and Europe for canning.

The test for toxin level is tricky

The test for toxic level is usually rather tricky. This is because different countries have different acceptable level of toxins. For example, Country X carries out a less stringent test on sample A and the results may show a mycotoxin level of as low as 0%. However, Country Y's test result on this similar sample may show positive results. Countries more stringent towards the level of toxins would choose to purchase or use machines that are highly sensitive and are able to detect very low concentrations of toxins.

Singapore's acceptability level of toxins is sensitive but it is not as sensitive as Japan's. The reason behind this is that AVA chooses to balance cost and efficiency of the measurement methods. A more sensitive machine is more expensive and takes a longer time to test samples. In Singapore, the CODEX standard is used. The CODEX standard, named after the Codex Alimentarius Commission, was created in 1963 by the World Health Organisation (WHO) to develop food standards, guidelines and related texts such as codes of practices under the WHO Food Standard Programme. The main purposes of this Programme is to protect the "health of the consumers and ensuring fair trade practices in the food trade, and promoting coordination of all food standards work undertaken by international governmental and non-governmental organizations."(FAO/WHO Food Standards, 2010.) This standard is used as it is recognized by more than 180 countries around the world. Hence, even if Singapore's toxic sensitivity is not as high as Japan's; it is still internationally recognized and acceptable.

Contaminants Laboratory

With the increase of chemicals and pollutants being thrown into the sea and water sources, there is a need to test imported foods for chemical contaminants. In AVA, the common contaminants tested for are:

Toxic metals (lead, mercury, arsenic, cadmium and tin) in seafood and other marine products, offal, processed meat, canned food and water.

Polychlorinated Biphenyls (PCBs).

Chloropropanols like 3-monochloropropane-1,2-diol (3-MCPD) and 1,3-dichloropropanol (1,3-DCP).


Generally, the tests are done using a liquid chromatography / mass spectrometer / mass spectrometer (LC /MS /MS) method or the Gas chromatography / Mass spectrometer (GC / MS) method. This lab is important as the tested contaminants are usually very toxic and some are carcinogenic eg: 3-MCPD in soy sauce. By using state of the art facilities, contaminants can be easily tested by injecting the liquid sample into the machine. In this laboratory, AVA usually tests the food consumed by consumers. For instance, AVA only tests the durian's flesh for contaminants and the husk is not included. The overview processing methods for contaminants are:

Preparation of the sample by grinding, extracting the parts for sampling and etc.

Extraction of the contaminants from parts of the food such as fish.

Usage of the Immunoaffinity column method for cleaning. This method is a very effective method of clean-up.

Usage of HPLC for Quantitative analysis.


In conclusion, as consumers, we will want our food to be safe. However, as much as the AVA can do to detect and deter contaminated food from entering Singapore, it is still our responsibility to process and prepare food safely for our own consumption. As quoted, "The assurance of food safety requires the combined effort of the government, the food industry and the consumer." (Agri-Food & Veterinary Authority, 2010.) Ultimately, it is our own responsibility to ensure that we practice safe food handling measures to protect ourselves and our family.