Leftover rice risks from Lifehacker

One of my former roommates was a straight edge punk-loving vegan for a while. Now he eats meat and drinks beer, but for a while he survived on rice and sriracha. Sometimes he left his steamed rice out overnight – making some egg-free fried rice the next day. This was before either of us knew much about Bacillus cereus and rice.

Earlier this week Claire Lower from Lifehacker emailed a couple of questions about leftover rice safety. The Lifehacker folks often ask really good questions about the science and why behind food safety recommendations – Claire included. Claire wanted to know why some guidelines say not to leave rice out on the stove over night.

I sent Claire a couple of papers including this one which is an oldie (1974), but a goodie from Gilbert and colleagues which included this awesome B. cereus spore/vegetative cell growth figure (right, exactly as shown) highlighting anincrease of a log or more within 4 hours once in vegetative state.

We looped Don into our discussion and he pointed out the somewhat common practice of boiled and then fried rice in some Asian cooking techniques.

According to Benjamin Chapman, Food Safety Specialist from North Carolina State University, cooking rice doesn’t necessarily kill all the pathogens that may be lurking about. “The issue with rice,” he explained to me over email, “is that one pathogen, Bacillus cereus, is quite prevalent in dried rice (some sources say ubiquitous), likely as spores. The spores may survive cooking. If cooked rice is subsequently held at room temperature, the spores can come out of their protective form, germinate, and vegetative forms multiply. The cooked rice environment provides a lot of water and nutrients for growth. As a by-product of growth, they create a couple of toxins, including a heat-stable one.”

Beyond refrigerating any home-cooked rice, a sense of vigilance is helpful when dining out. According to food scientist Donald Schaffner of Rutgers University, some restaurants “cook up a large batch of rice, hold it at room temperature all day,” and then take portions from the batch as needed. “Because Bacillus makes a heat stable toxin,” he explained “this is not a best practice, and has led to outbreaks in the past.” “Heat stable” means that the toxin can survive boiling and, once the rice is cooled into the “danger zone” of 59-122°F, the bacteria can multiply, making even more of the toxin. Sushi rice, he noted, shouldn’t be a problem as vinegar is added to lower the pH, allowing it to be held safely at room temperature.

Food fraud ‘Plastic rice’ seized in Nigeria

Martin Patience of BBC News reports Nigeria has confiscated 2.5 tonnes of “plastic rice” smuggled into the country by unscrupulous businessmen, the customs service says.

plastic-riceLagos customs chief Haruna Mamudu said the fake rice was intended to be sold in markets during the festive season.

He said the rice was very sticky after it was boiled and “only God knows what would have happened” if people ate it.

It is not clear where the seized sacks came from but rice made from plastic pellets was found in China last year.

Rice is the most popular staple food in Nigeria.

The BBC’s Peter Okwoche says it is the only foodstuff that crosses cultural and ethnic lines across the country.

Whoever made this fake rice did an exceptionally good job – on first impression it would have fooled me. When I ran the grains through my fingers nothing felt out of the ordinary.

But when I smelt a handful of the “rice” there was a faint chemical odour. Customs officials say when they cooked up the rice it was too sticky – and it was then abundantly clear this was no ordinary batch.

They’ve sent a sample to the laboratories to determine exactly what the “rice” is made of.

They are also warning the public not to consume the mystery foodstuff as it could be dangerous.

Fake food scandals are thankfully rare in Nigeria when you compare it to countries such as China.

The big scandal here is fake pharmaceutical drugs that kill a huge number of people every year.

A total of 102 sacks, each containing 25kg (55lb), was seized.

Mr Mamudu did not explain how the plastic rice was made but said it had been branded as “Best Tomato Rice.”

Why government regulation is coming to sushi

Cynthia Labelle-Tun, president of Edo Sushi Expresswrites in Food Safety Magazine:

I have been involved in the sushi industry since 2000 when my husband, Thihan Tun, and I opened Tun Asian Foods. We were an exclusive on-site sushi provider for Stop & Shop Supermarkets between 2002 and 2005. In 2005, we parted ways with Stop & Shop and decided to change our focus to delivery sushi in the New England region. Since then we have worked to provide safe and delicious food to businesses throughout the region.

recipesushi-rice-recipeOur strong focus on food safety came about due to our decision to focus on delivering fresh sushi. We already had a basic on-site Hazard Analysis and Critical Control Points (HACCP) plan and Standard Operating Procedures, but delivering fresh sushi requires special handling due to perishability issues. This caused Edo Sushi Express to begin the long road to a deeper understanding of sushi food safety. One of the results of this road was the law in Connecticut changing the way the health department looks at sushi rice.
Sushi rice as a cause of human illness or death could not be found by this author.

However, local health officials get very concerned when sushi rice is held in a rice warmer with a temperature of approximately 110 °F. Rice falls under the category of starchy foods served warm during meals. Normally, it would be held at a temperature of 135 °F or above to avoid bacterial growth. If the rice is not acidified, the temperature must be below 41 °F or above 135 °F.
Sushi chefs in the United States are usually trained by their peers and/or the companies they work for. The lead sushi chef must usually have an up-to-date ServSafe food handling license.

Another requirement for most sushi bars today is an HACCP plan. The HACCP plan will document the risks involved with making sushi and make note of the need for rice acidification.  The seasoned vinegar added to sushi rice acidifies it. The pH must be maintained below 4.6. Acidified rice is considered, in most places, to be considered potentially nonhazardous.
In fact, sushi rice is not a food hazard if it is made correctly. The preparation of sushi rice is different than regular rice. After the rice is steamed, it is cooled for a short time; seasoned rice vinegar is then mixed in with the cooked rice. It is the responsibility of the sushi chef to check the pH level of the rice using litmus paper or a pH testing monitor. The pH level is recorded in a pH log. This pH log is a tool for the local health official to check on the safety of the sushi rice.

In Connecticut, as a sushi bar operator and sushi supplier, our company has had to deal with the lack of a state-wide accurate policy on sushi rice safety. This lack of a coherent policy has made the actions of local health officials subjective about sushi rice. A sushi chef in one health district is met with differing requirements from a health district in the next county. Some examples of subjective decisions by health inspectors include:
1) A health inspector stated that after 2 hours at room temperature, the sushi rice had to be discarded.
2) A different health inspector insisted that sushi rice had to be held at 41 °F while making sushi.
3) A third health inspector insisted that the rice had to be above 135 °F at all times during the sushi-making process.

imagesThese were clear examples of how the lack of a state-wide food safety policy for sushi rice leads to confusion for the sushi chef trained in rice acidification. In fact, with all the discussion about sushi rice, the fragility of fish at room temperature was never mentioned in any of these situations.

The only way to deal with this type of situation is to change the law. If there is no law, then it needs to be created. Most states have different agencies dealing with different food venues. They might include the Department of Agriculture (grocery stores), Department of Public Health (catering, special events) and Department of Consumer Protection (restaurants). Interestingly, food safety laws and rules are not always shared between agencies. This is true in Connecticut. The law regarding sushi rice has to be changed on a per agency basis.

The Connecticut sushi rice law is the only one of its kind in the United States. It was signed by Governor Malloy in July 2015. Prior to this law, the Department of Public Health and local health departments were not required to allow acidification of sushi rice as an alternative to refrigeration. This new law gives the Department of Public Health the flexibility to make specific demands that will more than likely include a pH log, a rice recipe tested by a lab and an HACCP plan. The final text of the law reads as follows:
“Not later than October 1, 2016, the Commissioner of Public Health…with the Commissioner of Consumer Protection, shall adopt regulations…to allow the acidification of sushi rice as an alternative to temperature control under specified circumstances.”

Government regulation is coming to US sushi

Cynthia LaBelle-Tun,  president of Edo Sushi Express. writes in Food Safety Magazine that she has been involved in the sushi industry since 2000 when my husband, Thihan Tun, and I opened Tun Asian Foods. We were an exclusive on-site sushi provider for Stop & Shop Supermarkets between 2002 and 2005. In 2005, we parted ways with Stop & Shop and decided to change our focus to delivery sushi in the New England region. Since then we have worked to provide safe and delicious food to businesses throughout the region.

sushi.riceOur strong focus on food safety came about due to our decision to focus on delivering fresh sushi. We already had a basic on-site Hazard Analysis and Critical Control Points (HACCP) plan and Standard Operating Procedures, but delivering fresh sushi requires special handling due to perishability issues. This caused Edo Sushi Express to begin the long road to a deeper understanding of sushi food safety. One of the results of this road was the law in Connecticut changing the way the health department looks at sushi rice.
Sushi is a traditional Japanese food that has been incorporated into the American cuisine, and as it has grown in popularity throughout the country, the health authorities in states and municipalities have had to grapple with the issue of food safety. Sushi is a Japanese word that means “seasoned rice.” And it is the sushi rice that concerns many health officials. The concern for health officials is the growth of bacteria that will normally begin growing in food held at room temperature within 2 hours.
In the United States, very few people die from eating sushi. Death from eating bad sushi is usually attributed to fugu, a type of poisonous fish rarely eaten in the United States. People do get sick from eating sushi, but the cause for illness is usually poorly handled fish. An example of this occurred earlier this year with a Salmonella outbreak caused by raw tuna. Salmonella is caused when food is exposed to feces. It is highly likely that the fish processor, in China or Indonesia, washed the tuna with dirty water. Raw fish to be used in sushi must be handled with care. Salmonella bacteria will not die if the fish is frozen, it will only stop growing.

Temperature control: Bacillus cereus cases on rise

Bacillus cereus bacteria is one of the potential causes of food poisoning. A recent study in Analytical and Bioanalytical Chemistry shows that this versatile pathogen produces 19 different variants of a poison that causes nausea and vomiting in human beings. This variety could explain why some cases are relatively benign and others can result in death.

sushi.riceAcross Europe, the number of food poisoning cases caused by the Bacillus species is on the rise. While unpleasant, infections resulting from B. cereus are usually not life-threatening. Depending on the toxin that is released by the bacteria, patients suffer either from diarrhea or from nausea and vomiting. The results can be more serious, however, with death occurring in some very rare cases.

The form of the illness that causes nausea and vomiting is known as emetic. The toxin responsible for this is cereulide. Researchers from Technische Universität München (TUM) and the University of Veterinary Medicine in Vienna have now developed a method for detecting this toxin. In the process, they identified 18 further variants to add to the cereulide already known to scientists.

Recently, around 100 children and staff contracted a B. cereus infection at a number of daycare centers near Paderborn in Germany. It turned out that they had all eaten rice pudding supplied by the same caterer. It is known that consuming pre-prepared meals increases the risk of food poisoning. The types of foods most likely to harbor B. cereus are starchy staples like rice, pasta and potatoes.

“A poor temperature management often plays a role,” explains professor Thomas Hofmann. “The bacteria multiply, for example, in food that has been pre-cooked and then not heated up enough, or else not adequately cooled down beforehand.”

In addition, B. cereus can produce spores that can survive high heat — and which are still capable of producing viable bacteria at lower temperatures. These then often form bacterial toxins, which are in turn heat-stable — like cereulides.

 Chemodiversity of cereulide, the emetic toxin of Bacillus cereus; Sandra Marxen, Timo D. Stark, Elrike Frenzel, Andrea Rütschle, Genia Lücking, Gabriel Pürstinger, Elena E. Pohl, Siegried Scherer, Monika Ehling-Schulz, Thomas Hofmann; Analytical and Bioanalytical Chemistry; DOI: 10.1007/s00216-015-8511-y

44 kids sickened: Ottawa Chinese food takeout fined in summer camp food poisoning

A west Ottawa restaurant has been fined by Ottawa Public Health after rice it served made dozens of people sick and sent six children to hospital from a summer camp.

Lotus Chinese Food TakeoutParamedics were called to St. Cecilia School the afternoon of July 31 after several children and adults from the Tian Tian Chinese Summer Camp reported feeling ill.

Six children suffering from vomiting, dizziness and diarrhea were taken to hospital with suspected food poisoning. They were all released later that day.

Ottawa Public Health said in a statement Friday they inspected three restaurants that provided food for the camp that week. Two of those restaurants passed but the third, Lotus Chinese Food Takeout on Fallowfield Road, did not.

After interviewing more than 90 people from the camp, Ottawa Public Health said a total of 44 people felt sick after eating a fried rice dish from Lotus.

Analysis showed the presence of Bacillus cereus, a bacterium that releases toxins causing symptoms reported by those who got sick, in the rice and a noodle dishes from Lotus.

Rot, corruption at Thai rice warehouses

Inspectors found rotten and weevil-infested grain, along with evidence that large stocks were replaced with old or inferior grades.

thai-rice-warehouseCorruption under the previous government’s rice-pledging scheme was one of the main reasons for the May 22 coup d’etat.

The chairman of a sub-committee reviewing the inventory, ML Panadda Diskul, said a large quantity of rice was discovered to be missing in just the first two days of the inspection, the Bangkok Post reported.

He said military and police teams will visit about 1800 warehouses nationwide to inspect registered stocks of 10 million tons.

Panadda said some rice sacks bore code numbers that did not match documents provided by the warehouse owners, raising suspicions that pledged rice had been replaced with old or inferior rice bought from mills at lower prices.

Are you cereus?

Our usual evening schedule is dinner, a bit of hockey on TV and then wind the kids down with books or a bath before bed. Sometimes it takes 20 minutes to get them to sleep, sometimes 2 hrs. After losing a few meals by leaving our dinner leftovers out for too long due to an extended bedtime routine, we’re now in the habit of refrigerating extras before we sit down to eat.

Tonight’s risotto was packed up and chilling to avoid growing Bacillus cereus (linked to rice dishes 50 per cent of the time).

Bacillus cereus is sort of a fun pathogen (except for those who are affected by it): Two different toxic proteins can be produced by the bacteria as it grows. The one that causes vomit is preformed in food, the one that causes diarrhea is released by the bacteria as it grows in the body.

Turns out that toxin stability in food also plays a part in illnesses.

Effect of temperatures on the growth, toxin production, and heat resistance of bacillus cereus in cooked rice
Foodborne Pathogens and Disease. February 2014, 11(2): 133-137. doi:10.1089/fpd.2013.1609
WangJun, DingTian, and OhDeog-Hwan

ABSTRACT
Bacillus cereus is capable of producing enterotoxin and emetic toxin, and Bacillus foodborne illnesses occur due to the consumption of food contaminated with endospores. The objectives of this study were to investigate the growth and toxin production of B. cereus in cooked rice and to determine the effect of temperature on toxin destruction. Cooked rice inoculated with B. cereus was stored at 15, 25, 35, and 45°C or treated at 80, 90, and 100°C. The results indicated that emetic toxin was produced faster than enterotoxin (which was not detected below 15°C) at all the storage temperatures (15–45°C) during the first 72 h. Emetic toxin persisted at 100°C for 2 h, although enterotoxin was easily to be destroyed by this treatment within 15 min. In addition, B. cereus in cooked rice stored at a warm temperature for a period was not inactivated due to survival of the thermostable endospores. These data indicate that the contaminated cooked rice with B. cereus might present a potential risk to consumers. Results from this study may help enhance the safety of such food, and provide valuable and reliable information for risk assessment and management, associated with the problem of B. cereus in cooked rice.

And from the sort of obvious file, the authors say, “These data indicate that the contaminated cooked rice with B. cereus might present a potential risk to consumers.” Uh huh. It’s not just the data, but the many recorded outbreaks.

22 sickened; outbreak of Staphylococcal food poisoning from a military unit lunch party

I’ve never served in the military but am proud of the work I’ve done with the U.S. military over the years on food safety training, and have met a lot of great people.

But, as the U.S. Centers for Disease Control reports, on July 30, 2012, the emergency department at a military hospital was visited by 13 persons seeking care for gastrointestinal illness with onset 2–3 hours after a work lunch party. The hospital responded by opening up temporary evaluation and treatment capacity in primary-care clinics and a progressive-perlo.sausagecare unit and by diverting one patient to a local civilian hospital. An immediate outbreak investigation was conducted by local military public health personnel with assistance from CDC. Initial epidemiologic analysis implicated “perlo” (a chicken, sausage, and rice dish) and bacterial intoxication as the outbreak mechanism. This enabled public health personnel to 1) recommend no further consumption of perlo and 2) reassure appropriate authorities that no additional ill persons likely would be seeking care and advise that nothing more than supportive care of ill persons likely would be required.

After interviewing party attendees, investigators found nine additional persons who met their case definition. Subsequent CDC laboratory analysis of a sample of perlo detected staphylococcal enterotoxin A, supporting the epidemiologic findings. Improper food handling and preparation measures were identified and addressed by the appropriate authorities, who provided additional detailed education on food preparation safety for the persons who prepared the meal.

On July 29, the raw chicken thighs and sausage were defrosted in the microwave. The defrosted chicken thighs were cooked in a stock pot of boiling water. After cooling, the chicken was removed from the thigh bones by hand and placed back into the stock pot. Sausage was cooked in a skillet and added to the pot. Onions and other seasonings were sautéed in the sausage oil and added to the pot. To complete the perlo, rice was added to the stock pot and cooked until all remaining water was absorbed. The pot of cooked perlo then was placed in an unheated oven for approximately 8 hours overnight. On the morning of July 30, the perlo was found to be warm. It was transferred to a slow cooker for reheating for approximately 1 hour on a high setting before transport and consumption.

Don’t leave food, especially rice, at room temperature for eight hours. Put it in the fridge. Must not have had a military food safety type at this party, because they know their stuff.

Effect of temperatures on the growth, toxin production, and heat resistance of Bacillus cereus in cooked rice

I never order rice when I’m out. I cook it better than I used to for the gluten-free wife, and the kid, who is friends with a kid whose Chinese mom makes excellent stir-fry that I can’t replicate.

But it only took me about 15 years to learn how to cook steak properly, so maybe, soon.

When I make rice, it’s into the refrigerator reasonably fast. But lots of asparagus-and-chicken-fried-ricepeople leave it out overnight and that’s the problem.

As explained by Wang et al in Foodborne Pathogens and Disease:

Bacillus cereus is capable of producing enterotoxin and emetic toxin, and Bacillus foodborne illnesses occur due to the consumption of food contaminated with endospores. The objectives of this study were to investigate the growth and toxin production of B. cereus in cooked rice and to determine the effect of temperature on toxin destruction. Cooked rice inoculated with B. cereus was stored at 15, 25, 35, and 45°C or treated at 80, 90, and 100°C. The results indicated that emetic toxin was produced faster than enterotoxin (which was not detected below 15°C) at all the storage temperatures (15–45°C) during the first 72 h. Emetic toxin persisted at 100°C for 2 h, although enterotoxin was easily to be destroyed by this treatment within 15 min. In addition, B. cereus in cooked rice stored at a warm temperature for a period was not inactivated due to survival of the thermostable endospores. These data indicate that the contaminated cooked rice with B. cereus might present a potential risk to consumers. Results from this study may help enhance the safety of such food, and provide valuable and reliable information for risk assessment and management, associated with the problem of B. cereus in cooked rice.