Great for reheating, lousy for cooking: How food service uses microwaves in Minnesota

Uneven cooking due to consumer use of microwave ovens to cook food products that have been prepared but are not ready to eat has been a documented risk factor in several foodborne disease outbreaks.

img_microwaveHowever, the use of microwave ovens in restaurants and other food service establishments has not been well documented. The aim of this study was to describe the types of food service establishments that use microwave ovens, how these ovens are used, types of foods heated or cooked in these ovens, types of microwave ovens used in food service establishments, and the level of compliance with U.S. Food and Drug Administration (FDA) guidelines.

From 2008 to 2009, the Minnesota Department of Health collected data from a convenience sample of 60 food establishments within the state. Facility types included fast-food restaurants, sit-down restaurants, school food service, nursing homes, hotels and motels, and daycare centers. Food preparation practices were classified as prep-serve, cookserve, or complex. Minnesota environmental health specialists administered a study questionnaire to managers during routine inspections. Establishments included in this study reported using microwave ovens primarily to warm commercial ready-to-eat products (67%) and to warm foods for palatability (50%). No minimum temperatures are required for these processes because these foods do not require pathogen destruction. However, food establishments using complex preparation practices more often reported using microwave ovens for multiple processes and for processes that require pathogen destruction. For establishments that did report microwave oven use for food requiring pathogen destruction, the majority of managers reported following most FDA recommendations for cooking and reheating for hot-holding potentially hazardous foods, but many did not report letting food stand for 2 min after cooking.

Additional training on stand time after microwave cooking could be beneficial because of low reporting of this practice among study participants.

Microwave cooking practices in Minnesota food service establishments

Journal of Food Protection, Number 3, March 2016, Pages 507-511, DOI:

Hedeen, D. Reimann, and K. Everstine

‘Bacteria and stuff, they’re the sort of risks’ Kitchen staff at Brisbane aged home told to ‘reuse’ and ‘reheat’ leftover food

It’s bad enough that Australian hospitals serve raw sprouts to the ill and infirmed, a leading aged care provider in Australia has dictated to kitchen staff to “reuse” and “reheat” leftover food.

blue.careKitchen staff at Blue Care’s Wynnum facility have been told in a memorandum obtained by The Courier-Mail that “all left over food items should be getting sent back to the Main Kitchen, so the Cooks can determine if we can reuse.”

After inquiries from The Courier-Mail, Blue Care’s executive director Robyn Batten said the memo had been investigated and it is “poorly worded” and not indicative of the organisation’s policy or practices in any kitchen.

The memo, written by the facility’s hospitality team leader, includes a handwritten extra note that specifies to “reheat food.”

“The memo refers to returning food to the kitchen. However, the purpose of this is not for re-use, but to determine the amount of wastage, identify popular dishes and spot over production in the kitchen,” Ms Batten said. “It is also a good way of monitoring if residents are eating an adequate diet to support their nutritional requirements.”

The memo also tells kitchen staff: “Please be advised under no circumstance that any food item that has been prepared and cooked in the Main kitchen should be getting taken home.” memo is dated July 17 2015 and was sent to all kitchen staff by Ryan Moore, the facility’s hospitality team leader.

Ms Batten said she was “not aware” of issues with staff taking home food prepared for residents.

Bluecare is Australia’s largest not for profit provider of aged, disability and community services.

The site at Wynnum generates 158 meals three times a day.

Ms Batten said the Wynnum kitchen passed food safety audits.

That should provide absolutely no assurance of anything: Guess they haven’t heard about the problems with audits.

Queensland Aged and Disability Advocacy chief executive officer Geoff Rowe said there would be significant concerns if food was being reheated with elderly people particularly vulnerable to bacterial illness.

“Of concern if we’re talking about reheated foods … the bacteria and stuff, they’re the sorts of risks,” he said.

Chief Executive of Council of the Aging Mark Tucker-Evans said food quality and safety needed to be of upmost importance at aged care facility.

Nosestretcher alert: don’t reheat these foods

The New Zealand Herald says there are 5 five foods that shouldn’t be reheated because of risks. The headline and lede aren’t helpful.

Three of them are cited for foodborne illness reasons:

1. Chicken

As well as other poultry, it’s well known chicken requires careful preparation and cooking to avoid salmonella contamination.3cca9502c5860cc6a373976ef8c0d896

The main issue with reheating chicken in a microwave, as opposed to other methods, is that the heatwaves don’t evenly cook all parts of the food.

How about cook it to 165F in the first place – and then reheat to and check with a digital tips-sensitive food thermometer.

2. Rice

According to the Food Standards Agency, the storage of rice is crucial. Being left out at room temperature provides the perfect breeding ground for spores which could be the cause of vomiting and diarrhoea.

3. Potatoes
Like rice, potatoes require proper storage after cooking. Otherwise they provide conditions ideal for bacterial growth. Leaving them at room temperature, particularly when they’re covered in tin foil, can result in the growth of Clostridium botulinum (botulism). They need to be cooled and refrigerated. Reheating them won’t kill off the bacteria either.

Or, leaving these foods at room temperature is risky. Reheating isn’t a factor.

Husband tells of horrific moment of wife’s death after eating reheated Christmas dinner at UK chain pub

 A husband has told how his dying wife’s eyes rolled back into her head after eating a reheated Christmas dinner at one of the country’s top pub chains, a court heard.

237E855900000578-0-image-55_1416934800709Mother-of-one Della Callagher died and 32 other diners became seriously ill after eating the turkey dinner at the Railway Hotel, Hornchurch, Essex.

The 46-year-old became unwell on Boxing Day and her devastated husband told the court how his wife began shaking and her eyes rolled back into her head.

Snaresbrook Crown Court heard she was sent home from Queen’s Hospital, Romford, and she died on December 27.

Guests paid £39.95 for a meal which had been cooked the day before and given a second blast on a hotplate before it was brought to the table.

Prosecutors claimed the food was not allowed to cool when it was first cooked and then not properly reheated, creating a perfect breeding ground for the deadly Clostridium bacteria.

After the outbreak landlady Anne-Marie McSweeney, 40, and chef Mehmet Kaya, 37 disposed of all the waste food, preventing health inspectors from taking samples. They also forged kitchen records.

They were both found guilty perverting the course of justice for falsifying food safety records.

More than 30 sick from bad reheating of spaghetti at Hawaiian school

State health officials have found that bacteria-tainted spaghetti was the cause of an illness that struck dozens of students at Waipahu Elementary School earlier this month.

The state Department of Health said spaghetti cooked the previous day at the Oahu school was not properly heated the day it was served, spaghetti.schoolwhich created “an environment for bacteria growth.” The food also may not have been properly cooled the day it was cooked, the DOH said in a statement today.

“An inspection and interviews with cafeteria employees revealed food preparation violations that could be corrected with proper training and follow through,” said Peter Oshiro, head of the department’s Sanitation Branch. “We understand the school closed the cafeteria to retrain their food service staff and ensure safe food practices.”

Two adults and more than 30 students came down with dizziness, nausea and vomiting on Dec. 10. School officials immediately suspected food poisoning as the cause.

Cook and reheat the damn ham; don’t hire unlicensed caterers; Clostridium perfringens strikes Las Vegas lunch

 On Dec. 8, 2011, a biz in Las Vegas had a catered lunch.

Less than a day later, a bunch of them were barfing.

The Southern Nevada Health District (SNHD) began an investigation the next day after receiving numerous reports of barfing among attendees; excerpts from their report are below.

Approximately 150 people work at Business A. Of the 63 employees who replied to the electronic survey, 50 reported they consumed food and/or drinks at the luncheon. Of the 50 luncheon attendees, 21 (42%) people met the case definition. An additional 29 people who ate at the luncheon but did not become ill served as non-case study participants. No ill person sought medical attention from a healthcare provider.

The caterer had a health card that is issued by the SNHD to food handlers. However, the caterer did not hold a catering permit issued by the SNHD, so health types don’t know if the same caterer sickened others at others meals because SNDH only tracks complaints against licensed businesses.

Both the caterer and a representative from Business A reported that the caterer
arrived at 9:00 am on December 8, and lunch service started at approximately 1230 hrs
(meal start time among ill persons ranged from 1130 to 1900 hrs) (Fig. 1). The duration
of the luncheon was unknown.

The caterer reported that all foods served were pre-cooked and ready-to-eat. The ham and turkey breasts were transported to Business A in a cooler with ice. Both meats were further sliced onsite, placed in bowls and re-heated in 5-6 batches per meat in two small non-commercial microwave ovens that were provided by Business A at the catering site. The caterer reported that food batches were stirred during heating. The caterer alleged the temperature of the meat was 170°F (76.7°C) after heating, but it was unclear where the temperature was taken in the meat. Heated ham slices were pooled in one chafing pan and canned pineapple with its juice was added.

Heated turkey meat was pooled in another pan and heated canned gravy was added. The
chafing dishes containing the ham and turkey were warmed by pans of hot water that was heated with Sterno heaters. Both meats were stored in their respective chafing dishes for about 0.5 hr prior to eating, but the duration of time foods were stored in the chafing dishes was not known.

Upon collecting foods for testing, EH staff observed that leftover foods were stored in a refrigerator that displayed the temperatures of <40°F, with the bulk of the food stored in covered consumer-grade plastic containers. All remaining food in their original containers was collected for testing and included: Mashed potatoes, ham and pineapple topping, green beans, salad with fruits, and two mixed-food plates containing 1) Ham, turkey, mashed potatoes, stuffing, green beans, and 2) Stuffing, mashed potatoes, green beans.

I’m getting hungry.

The EH staff sent a formal notice to the caterer requiring all food operations to immediately cease and desist. They also required that the website which advertises the catering business be modified to announce that a permitted food facility will be providing the food to future events that are planned by the catering company. Additionally, EH also issued a bill to the caterer charging for the time that EH staff had spent in investigating the outbreak.

The isolation of C. perfringens was strongly suggestive that ham was the vehicle of transmission, and an error likely occurred during its re-heating and hot holding during the luncheon service. The heat generated by a small microwave oven might be insufficient to bring all portions of the ham to above 165°F (74°C) to destroy the C. perfringens bacteria. When the heating process is not evenly accomplished, the surviving C. perfringens bacteria can multiply and undergo sporulation. During the holding period where food is kept warm in covered chafing pans for extended periods of time, the spores can germinate to produce vegetative cells and multiply rapidly to large numbers. Ingestion of the bacteria during the luncheon may have resulted in further multiplication and sporulation in the intestine. The release of enterotoxin when C. perfringens sporulates can cause acute diarrhea. To prevent the proliferation of pathogens in potential hazardous food, the US FDA Food Code 2009 recommends that food that are reheated in a microwave for hot holding shall be reheated so that all parts of the food reach a temperature of at least 74oC (165oF) and the food is rotated or stirred, covered, and allowed to stand covered for 2 minutes after reheating (Section
3-403.11.B). Also, hot holding of such foods should occur at 57oC (135oF) or above
(Section 3-501.16.A1).

The majority of C. perfringens outbreaks are often the results of improperly cooled food or food held at room temperature for extended periods. Coupled with concurring epidemiological findings that the contamination and proliferation of the bacteria may have occurred at the luncheon, no further food traceback or recall action of the ham was implemented by the FDA.