In May and June 2019, two food poisoning outbreaks related to the consumption of soft scrambled eggs were reported in Hong Kong, involving 7 and 40 victims respectively.  The victims suffered from abdominal pain, vomiting, diarrhoea and fever.  Some required hospitalisation.  These two cases were associated with inadequate cooking of soft scrambled eggs and/or improper holding temperature of the eggs after cooking, the causative agent being Salmonella.

Undercooked egg dishes such as soft scrambled eggs have an inherent risk of food poisoning caused by Salmonella.

What is the Source of Salmonella?  The Hen or the Egg?

Salmonella first infects hens and then their eggs.  During or after egg laying, eggs can become contaminated with Salmonella through the eggshell as a result of contaminated faeces.  Salmonella can also contaminate eggs through infection of reproductive organs of hens before the shell is formed.  It is not possible to distinguish with the naked eye whether an egg is contaminated with Salmonella.

Risks of Consuming Undercooked Eggs

Salmonella can survive in undercooked eggs and cause food poisoning.  Improper storage temperature (e.g. room temperature at 25°C) will also facilitate Salmonella in undercooked eggs to multiply rapidly.  The incubation period for Salmonella ranges from 6 to 72 hours, usually 12 to 36 hours.  The symptoms include abdominal pain, vomiting, diarrhoea and fever.  In severe cases, which are less common, complications such as septicaemia, dehydration and even death may occur.  Just a small amount of Salmonella-contaminated eggs used in food preparation may lead to a number of food poisoning cases.

Implementing Five Keys to Food Safety to Reduce Food Poisoning

As food poisoning caused by Salmonella in egg dishes is related to improper cooking and holding temperature, special attention should be paid to whether the food is fully cooked and kept at proper temperatures.  Foodborne diseases can be prevented by practising the Five Keys to Food Safety, namely (1) to choose wisely; (2) to keep clean; (3) to separate raw and cooked food; (4) to cook thoroughly; and (5) to keep food at safe temperatures.

Thorough cooking and heating can destroy bacteria in food, including Salmonella.  Food should be cooked to a core temperature of at least 75°C.  Cooked foods that are served hot should be kept above 60°C prior to serving, while cold dishes should be stored at 4°C or below.  Moreover, cooked foods should be consumed immediately and not left at room temperature for more than 2 hours.  Cooked foods kept at room temperature for more than 4 hours should be discarded.

Examples of preparing egg dishes by following the Five Keys to Food Safety

Key Points to Note

• Salmonella can contaminate eggs during egg formation.  It is not possible to distinguish contaminated eggs from the normal ones with the naked eye.
• Salmonella can survive in undercooked food.  It is risky to consume egg dishes prepared with raw or undercooked eggs.
•  By following the Five Keys to Food Safety, the risk of foodborne illnesses can be minimised.

Advice to the Trade

• Follow the Five Keys to Food Safety to ensure that the food is thoroughly cooked and properly kept.
• Prepare scrambled eggs on a per-order basis and avoid leaving them at room temperature for a prolonged period of time.
• Avoid using cracked eggs in preparing dishes since they are more likely to be contaminated.
• Use liquid egg on the day of pooling and avoid topping up the liquid egg with new eggs.
• Use pasteurised eggs for food without heat treatment.
• Indicate the presence of raw or undercooked foods/ingredients in ready-to-eat items to help consumers make informed choices by providing a consumer advisory on labels or placards stating, for instance, "Consuming raw or undercooked foods may pose a higher risk of foodborne illnesses, especially for pregnant women, young children, the elderly and people with weakened immunity."

News on New Dishes

D Hall Chicken Curry

Rich in aroma and taste, curries are all-time favourite foods for many people.  In this issue, Mr CHEUNG, master chef of "hc:Bistro", will show us how to prepare the curry dish "D Hall Chicken Curry", so named as the social enterprise restaurant is situated at the former D Hall of Victoria Prison (now revitalised as Tai Kwun) in Central.  It is a characteristic dish inspired by the curry meals provided for inmates of the prison in the past.  Let's learn how to make it.

Tips from the Chef:

• Frying the chicken chunks briefly until golden brown and simmering them over low heat will keep the meat moist and tender.
• Add pineapple and raisins as side dishes.  Their sweet and sour tastes can neutralise the spiciness of curry.

Food Safety Plan Corner

D Hall Chicken Curry

Ingredients:
A whole chicken, tomatoes, garlic, ginger, onions, red peppers, black pepper, curry powder and masala powder

Steps:

1. Take out garlic, ginger, onions and red peppers from the dry goods shelves and rinse them thoroughly under clean running water.  Peel garlic, ginger and onions.  Puree garlic and grind ginger into paste.  Chop onions into small pieces.  Shred red peppers after removing stalks and seeds.  Set aside.
2. Take out tomatoes that are refrigerated at 4°C or below.  Rinse them thoroughly under clean running water.  Dice them after removing stalks and seeds.  Set aside.
3. Heat the wok and add some oil.  Stir fry garlic puree, ginger paste, onions and red pepper until fragrant.  Add curry powder, masala powder, tomatoes, black pepper and water into the wok and cook over low heat for about 3 hours to prepare the curry sauce.
4. Take out the chicken that is refrigerated at 4°C or below.  Rinse the chicken and cut it into chunks.  Marinate the chicken with garlic puree, curry powder and oil.
5. Preheat the griddle and add some oil.  Fry the marinated chicken until golden brown.  Add a pinch of salt and pepper for seasoning.
6. Put the fried chicken chunks into the curry sauce and simmer for about 15 minutes.

 Production Process

 

Briefing of Activities

1)  Relocation of Communication Resource Unit

The Communication Resource Unit (CRU) of the CFS was relocated from 8/F, Fa Yuen Street Municipal Services Building, 123A Fa Yuen Street, Mong Kok, Kowloon to Room 401, 4/F, Food and Environmental Hygiene Department Nam Cheong Offices and Vehicle Depot, 87 Yen Chow Street West, Sham Shui Po, Kowloon on 22 July 2019. 

The CRU maintains a rich collection of food safety resource materials which help consumers make informed food choices and the trade supply safe food.  The new CRU office has set up an exhibition hall with information corners and audiovisual facilities for visitors to gain direct access to food safety information in Hong Kong.  For enquiries, please contact the CRU at 2381 6096 during office hours.

Exit C of Nam Cheong MTR Station
Food and Environmental Hygiene Department Nam Cheong Offices and Vehicle Depot

2)  Food Adulteration (Metallic Contamination) (Amendment) Regulation 2018

The Food Adulteration (Metallic Contamination) (Amendment) Regulation 2018 (the Regulation) came into force on 1 November 2019.  It aims at enhancing regulatory control and updating the relevant standards, with a view to better protecting public health, facilitating effective regulation and aligning Hong Kong standards with the international ones.

The Regulation increases the number of metallic contaminants covered from 7 to 14, whereas the number of maximum levels (MLs) for metallic contaminants in respect of different foods and food groups is increased from 19 to 144.  Apart from providing definitions for individual foods and food groups, the Regulation replaces or deletes obsolete clauses and sets out principles for applying the MLs on food in a dried, dehydrated or concentrated form and compounded food.  In addition, there are transitional provisions laying down the grace periods for different kinds of food.

The Regulation was gazetted in June 2018 and vetted by the Legislative Council in October the same year.  To allow sufficient time for traders to adapt to the updated MLs for metallic contaminants (including identifying alternative sources of supply if needed), and for the local testing and laboratory sector to establish testing capability for the new MLs, the Regulation is first applicable to certain types of fresh food with a shorter shelf life (i.e. fruits and vegetables and their juice, animal and poultry meat, edible offal of animal and poultry, aquatic animals and poultry eggs which have not been subjected to a process of preservation, or have been preserved by chilling but not freezing).  Other foods which normally have a longer shelf/storage life will be covered with effect from 1 November 2020.

The CFS has conducted a series of technical meetings for the trade and other stakeholders to help them prepare for the commencement of the Regulation.  It has also complied the relevant guidelines for reference by the trade.

3)  CFS Instagram (IG) Page Goes Online

The CFS has been disseminating food safety messages to the general public through social media.  In addition to Facebook, the CFS has launched a new IG page to share food safety information with the public, including clarifying food misconceptions.  You are welcome to visit our IG page (www.instagram.com/cfs.hk) to learn more.

Follow us on  @cfs.hk
CFS Instagram page

Upcoming Activities

Roving Exhibitions on Food Safety

The CFS organises thematic exhibitions in shopping centres of public housing estates, Home Ownership Scheme estates and private housing estates, as well as government offices and markets managed by the Food and Environmental Hygiene Department (FEHD) across the territory.  There are exhibition boards on various food safety and nutrition topics, including the Five Keys to Food Safety, Nutrition Labelling, Trans Fat, Organic Food, Genetically Modified Food and Natural Toxins in Food.  The staff on site will show educational videos and distribute leaflets and souvenirs to visitors during the exhibitions.

The venue and time of the roving exhibitions will be published on the CFS website (https://www.cfs.gov.hk/tc_chi/whatsnew/whatsnew_act/whatsnew_act.html).  Members of the public are welcome to visit these exhibitions.

Food Safety Q&A

Will We Contract AIDS by Consuming Canned Fruits?

Siu Ming is having a fever.  His mother takes him to a doctor.

Doctor:  Good morning, kid.  What's wrong with you?

Mom:   Good morning, doctor.  My son had a slight fever the night before last.  I took his temperature this morning and it went up to 39ºC.  He's also experiencing diarrhea.

Siu Ming:  Doctor, I'm about to die.  I may have AIDS!  My classmate and I ate some canned pineapples at school the day before yesterday.  Both of us developed a fever that night.  We have become tired and weak.  We also have sore throats and can’t eat a thing.  I learnt from the Internet that HIV is present in canned pineapples.  That freaks me out!

Doctor:   HIV stands for Human Immunodeficiency Virus.  It is the cause of AIDS.  According to the World Health Organization, HIV can't be transmitted by water or food.  In fact, HIV doesn't live long outside the human body.  Even if the food contains small amounts of HIV-infected blood or semen, exposure to the air, heat from cooking and stomach acid would destroy the virus.  Based on the current scientific evidence, the World Health Organization and the US Centers for Disease Control and Prevention do not consider that food is a source of HIV infection.  There should be no worries about contracting AIDS because of eating canned fruits contaminated with HIV.  Your concerns are unfounded.

Let me examine you first.  Well, your throat is a bit red and swollen, it's a sign of mild inflammation.  It's likely that you are infected by your classmate.  I'll prescribe some medicine to you.  Come back two days later for follow-up consultation, and we'll see if you're getting better.  Don't worry.

Mom:   Thank you, doctor.  I'm relieved that my son is alright.

Truth Against Fallacy

Is Smoked Salmon Safer for Consumption Than Sashimi?

According to the Food Business Regulation under the Public Health and Municipal Services Ordinance (Cap. 132), sushi and sashimi are classified as restricted food.  Sashimi is food consisting of fillets of marine fish, molluscs, crustaceans, fish roe or other seafood to be eaten in its raw state.  It is a high-risk food that can lead to food poisoning and even parasitic infection if prepared improperly.

Does it mean that salted and smoked salmon is safer for consumption than sashimi?

Smoked salmon in the market is usually prepared by hot smoking or cold smoking.  In hot smoking, salmon is smoked at around 70°C to 80°C with the flesh thoroughly cooked.  As for cold smoking, the fish is smoked at a temperature not higher than 33°C.  It is not fully cooked and the protein in the flesh will not coagulate.  Unlike hot smoking, the cooking temperature of cold smoking is generally insufficient to eliminate pathogens like Listeria monocytogenes (L. monocytogenes).

L. monocytogenes is ubiquitous in the environment.  It can grow slowly at refrigeration temperatures.  Salmon, raw or cold-smoked, may contain a small amount of L. monocytogenes.  Various food recalls due to L. monocytogenes contamination in cold-smoked salmon have been reported all over the world.  There is also indirect epidemiological evidence associating contaminated smoked fish with human listeriosis cases.

Generally speaking, foods containing low levels of L. monocytogenes (e.g. <100 colony-forming units (cfu)/g) pose very little risk to consumers.  However, as the number of bacteria increases, consumers will be at risk of listeriosis.  While most healthy individuals do not develop symptoms or only have mild symptoms when infected, severe complications such as septicaemia, meningitis or even death may occur in the susceptible population, including the elderly, young children and people with weakened immunity.  Listeriosis during pregnancy can lead to miscarriage, stillbirth, premature delivery or infection in newborns.  Hence, effective control measures to prevent L. monocytogenes contamination and inhibit its growth are of prime importance in ensuring food safety in the production of cold-smoked salmon.

In summary, sashimi and cold-smoked salmon are high-risk foods.  Members of the public are advised to purchase them from reliable and reputable sources.

Advice to the Trade

• Observe Good Hygienic Practices in food processing to ensure that the food products will not pose risk to the public.
• Food businesses are recommended to implement the Hazard Analysis and Critical Control Points (HACCP) system to prevent food safety problems.  Relevant measures like raw material control, temperature control for finished products, staff training, proper arrangement of equipment and facilities in the production plant and effective environmental monitoring programmes can reduce the risk of L. monocytogenes contamination.
• Seek professional advice from food scientists if there is any doubt on whether individual food products can support the growth of L. monocytogenes.  Reference can also be made to the Codex Guidelines on the Application on General Principles of Food Hygiene to the Control of Listeria monocytogenes in Foods (CAC/GL 61-2007).
• Shops/Restaurants are required to obtain a relevant permit from the FEHD for selling sashimi for human consumption.
• An official health certificate issued by the place of origin can be obtained from importers to ensure that the food concerned has been properly handled (e.g. by good aquaculture practices and/or freezing treatment).

Brain Gym

Fill in the blanks

1. The cooking temperature of          a            is generally insufficient in eliminating Listeria monocytogenes in smoked salmon.
2. People with weakened immunity such as the elderly, pregnant women or      b          should avoid eating fish/seafood that are raw or not fully cooked.
3. The Code of Practice for Fish and Fishery Products issued by the Codex Alimentarius Commission states that freezing fish at -20ºC or below for 7 days or at -35ºC for about 20 hours can kill       c            and effectively minimise the risk of parasitic infection.

Answers:

a = cold-smoking      b = young children      c = parasites

Enquiries and Subscription

Printed copies of the Food Safety Bulletin can be obtained from the CRU at Room 401, 4/F, Food and Environmental Hygiene Department Nam Cheong Offices and Vehicle Depot, 87 Yen Chow Street West, Sham Shui Po, Kowloon.  For enquiries, please call 2381 6096.  The public may also visit the CFS website (www.cfs.gov.hk) for the online version.