FOOD FACTS FOR YOU!
Does the Plastic
in Water Bottles and Plastic Wrap Cause Cancer?
Milk Processing: Just What are Homogenization and Pasteurization?
Coming: Exciting Opportunities for Food Preservation
Kitchen
Food Safety
Safe
Food Tastes Great
Fingernails
as a Source of Germs
Looking
Ahead: Easter
What’s
On Your Mind? (canned items: toss or keep?)
Does the Plastic in Water Bottles and Plastic Wrap Cause Cancer?
The email message that you might receive would say something like this: “ I just wanted to pass some information on to you. I was watching Channel 2 this morning. They had a Dr. Edward Fujimoto from Castle Hospital on the program. He is the manager of the Wellness Program at the hospital. He was talking about dioxins and how bad they are for us. He said that we should not be heating our food in the microwave using plastic containers. This applies to foods that contain fat. He said that the combination of fat, high heat and plastics releases dioxins into the food and ultimately into the cells of the body. Dioxins are carcinogens and highly toxic to the cells of our bodies. Share this message with everyone you know.”
Or perhaps the email message would say that scientists have found that microwaved plastic wrap can give you cancer. The message ends with this text: "Pass this on to your friends: Saran Wrap placed over foods as they are nuked, with the high heat, actually drips poisonous toxins into the food." Or maybe the message says: “Don't freeze your plastic water bottles with water as this also releases dioxin in the plastic. Dr. Edward Fujimoto from Castle Hospital was on a TV program explaining this health hazard.” Since this type of message has been circulating for months, and since I have received several queries as to the validity of these messages, I wanted to address this issue.
Dioxins in plastic wrap? Dioxins and dioxin-related compounds are pollutants that mainly enter the environment (and food supply) as industrial by-products. Particular dioxin compounds are considered to be highly toxic, with known health hazards ranging from birth defects to cancer. Studies have shown that dioxins may be released into the atmosphere when chlorinated plastics such as polyvinyl chloride (PVC) — which is a component of some plastic wraps and food packaging — are incinerated at high temperatures, but there is no research demonstrating that dioxins are produced when the same plastics are heated in a microwave oven.
The other culprit: DEHA [Di(2-ethylhexyl)adipate] DEHA is a "plasticizer", a softening compound added to plastic products to make them more pliable. It is an ingredient in some plastic wraps. Studies have shown that DEHA can migrate into food under certain conditions. At issue is whether or not it is toxic to human beings. The current scientific consensus is that it is not, at least not in the minute amounts resulting from migration from plastics into foods. Even though DEHA has long been regarded as a possible human carcinogen, the U.S. Environmental Protection Agency removed it from its list of toxic chemicals in the late 1990s after concluding, based on a review of the scientific evidence, that "it cannot reasonably be anticipated to cause cancer, teratogenic effects, immunotoxicity, neurotoxicity, gene mutations, liver, kidney, reproductive or developmental toxicity or other serious or irreversible chronic health effects."
Critique. With some internet snooping of my own, I found this critique of the information that has been circulating by email: One- or two-minute health spots on local news programs are not ideal sources of medical information. While important basic information can be imparted in such a format, trying to explicate complex medical topics in a minute or two can easily mislead or confuse viewers, many of whom come away believing absolutely whatever they've heard (or think they've heard) because "a doctor on TV said it was true" — in this case an unshakeable belief that using plastic containers in microwave ovens causes cancer. That a doctor (or, more accurately, someone bearing the title "Dr.") appears on TV does not mean he's a leading practitioner in his field; it generally means only that he has something to say that a news director considers newsworthy, accurate or not. (As a note, the "Dr. Edward Fujimoto" identified in the piece is not a staff physician from " Castle Hospital " or a medical doctor or a food safety expert; he's a PhD involved in health education at Castle Medical Center in Kailua , Hawaii .) It's a pretty good assumption that if using plastic containers in microwaves — as millions of people have been doing for decades — posed a significant risk of cancer, you'd be hearing about it somewhere other than an e-mail forward of an anonymous summary of a morning news spot on a Hawaiian television station.
Food safety experts and toxicologists agree that the crucial issues noted in the email messages have been addressed by the FDA, the food packaging industries, and the food industry. The FDA imposes stringent regulations on plastics meant for microwaving. And there are no studies to indicate that dioxins can form at the temperatures used for microwaving foods.
The bottom line. While the
email messages that are circulating might be alarmist in nature, food safety
experts also agree that consumers should take the following precautions when
using plastic wrap or plastic containers:
• Only plastic containers or packaging labeled ‘Microwave
Safe' should be used in the microwave oven. Don't use plastic containers
such as margarine tubs or foam take-out boxes. These containers can warp or melt
in the microwave. So can thin plastic storage bags or plastic grocery sacks.
• If you do use plastic wrap to cover a dish you intend to
microwave, do not let the covering touch the food. Some of the plasticizer
in the wrap could migrate to what you're cooking, especially foods high in fat,
oil or sugars. Alternately, use waxed paper as a cover; or transfer the food
to a tempered glass container (like Pyrex or Corning ).
Consumers can feel reassured that research has found no ill-effects from consumption of plasticizers from FDA-approved plastic wraps, or from freezing or re-using plastic water bottles.
For more information on this topic:
• Food Facts for You! (Back issues: see P lastic and M icrowave; Care and Cleaning of Water Bottles) http://www.wisc.edu/foodsafety/wffoodfactsforyou.htm
• Urban Legends and Folklore http://urbanlegends.about.com/
• Toxins in plastics http://www.snopes.com/toxins/plastic.htm
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to top
Milk
Processing: Just What are Homogenization and Pasteurization?
The milk that I buy in the grocery store says ‘homogenized' or ‘pasteurized'. What does that mean? The milk that you find in a carton or container in the grocery store has gone through a series of processing steps to ensure both safety and quality. I would like to review a few of those steps.
Quality comes first. If you look into the history of milk processing in the United States , and elsewhere, you can find instances of unscrupulous behavior - usually where milk was adulterated with water in order to increase profit. Partly as a result, milk is one of the most legally controlled food commodities in the United States . State and federal laws regulate not only the quality of the milk (minimum fat and protein levels) but processed milk must also meet certain safety standards. Bacterial counts play a major role in the sanitary quality of milk on which quality grades are assigned. Generally, fluid whole milk for consumer use, also referred to as ‘market milk' has higher standards placed on it than milk which will be used for manufacturing purposes (cheese, dried milk, etc.)
Pasteurization. The aim of pasteurizing milk is to rid the milk of any disease-causing microorganisms that might be present, and to reduce the total bacterial count for improved keeping quality. Pasteurization also destroys lipase and other natural milk enzymes that cause changes in flavor and odor during storage. Pasteurization times and temperatures for many years were selected to ensure destruction of Mycobacterium tuberculosis , the bacterium that can transmit tuberculosis to humans. In more recent years, it was discovered that the organism causing Q fever, Coxiella burnetti , was slightly more heat resistant than the tuberculosis organism and so a more lethal heat treatment was required. According to the Center for Disease Control, most acute cases of Q fever begin with sudden onset of one or more of the following: high fevers (up to 104-105° F), severe headache, general malaise , myalgia , confusion, sore throat, chills, sweats, non-productive cough, nausea, vomiting, diarrhea, abdominal pain, and chest pain. Fever usually lasts for 1 to 2 weeks. The infection can lead to pneumonia in up to 50% of cases.
Heat treatments . Pasteurization involves heating for a stated time and temperature to ensure destruction of particular microorganisms. Standard pasteurization treatments for milk include:
• Batch pasteurization . 145.5 ° F for 30 minutes.
• HTST (high temperature, short time) pasteurization . 161 ° F for 15 seconds.
• UHT (ultra high temperature) pasteurization . 280 ° F for 2 seconds.
Pasteurized milk is not sterile and must be quickly cooled following pasteurization, and then stored under refrigeration to ensure safety. Most milk that you find in the grocery store is HTST processed. This rapid process ensures safety, while maintaining most of the flavor of raw (unpasteurized) milk. The higher temperature in UHT processing renders milk sterile, so that UHT milk is often sold in cartons, similar to juice boxes, on the grocery store shelf. Milk is rarely pasteurized in a batch process because the extended heating time causes unacceptable changes in the flavor and odor of the milk.
Homogenization. Whole milk and cream must be homogenized so that the fat doesn't clump together and rise to the surface. The purpose of homogenization is to break up the fat globules into such a small size that the fat remains in the watery milk matrix. Homogenization gives milk a richer taste and a whiter color (because light interacts with the dispersed fat in a different way).
Enrichment/fortification. In the United States , vitamins A and D are added to fluid milk before pasteurization. Vitamin D aids in the absorption of calcium – a prime mineral in milk, and essential for healthy bones. Vitamin A is also added to skim and reduced-fat milk because this vitamin is lost when the fat is removed to prepare low-fat fluid milk.
Coming:
Exciting Opportunities in Food Preservation
I am happy to report that the creative juices are flowing! A group of volunteers ‘met' by phone the end of February to begin to help design, or redesign, food preservation training for the state. Here are some notes and ideas generated so far. If you would like to add your ideas, or join the food preservation working group let me know.
• Offer training in several formats: the traditional 3-day course, and shorter seminars on specific topics (i.e. canning tomatoes).
• Keep training hands-on!
• Consider ideas to train 4-H youth.
• Communicate with fair superintendents re evaluation of home-preserved food.
• Develop ideas for displays that highlight food preservation. These displays might be useful for farmers' markets.
• Develop seasonal resources, such as a news release that highlights ways to preserve tomatoes. These resources should be available and ready when tomatoes are ripening in the garden.
• Offer updates via Wisline on major changes in canning and food preservation at the beginning of each summer.
These ideas, and more, are sure to keep me busy over the next few months. Look for more details via newsletter or email. My special thanks to the creative team: Gerry Berg-Sutten, Donna Hora-Schwobe, Pat Ludeman, Linda Olson, Lucia Patritto, Donna Peterson, Rita Straub and Dianne Weber .
Recent articles in several publications have highlighted the kitchen as a prime home for germs of all kinds, and have discussed either kitchen practices or common kitchen items which might help, or hinder, the battle against these germs. Following is a summary.
Foodborne pathogens and common kitchen practices. Scientists at Rutgers University in New Jersey collaborated with colleagues in the United Kingdom to determine the survival of Salmonella , Campylobacter and E. coli O157:H7 during washing and drying of dishes, and the possibility of cross-contamination. At least some of the dishes remained contaminated with pathogens even after a typical washing-up. Both E. coli and Salmonella survived towel- and air-drying of dishes. Each time, a towel used to dry contaminated dishes was found to have become contaminated with pathogens itself. Sponges used to wash contaminated dishes easily became contaminated. Both towels and sponges that came into contact with contaminated dishes could transfer pathogens to kitchen counters and other surfaces.
Keeping bugs at bay in the kitchen. The January/February Nutrition Action Health Letter evaluated products which might serve to help keep foodborne pathogens at bay.
? Alcohol washes . While soap and water is the best way to get rid of germs on your hands, if your household includes people with weakened immune systems, or there's a bug going around in your family, then alcohol-based hand gel washes might provide some extra protection. Alcohol washes are so good at killing germs that in 2002 the Centers for Disease Control (CDC) recommended that hospitals use them instead of antibacterial soap. Just make sure the alcohol-based gel wash contains a moisturizer or emollient, and that ‘ethyl alcohol 62%' is one of the active ingredients.
? Clean cutting boards . It isn't a question of whether a wooden or a plastic cutting board is better, either will work just fine, what's important is that you wash it properly. Wash used cutting boards in hot, soapy water, or in a dishwasher. If washing a cutting board by hand, use plenty of scrubbing to get into marks left by the knife blade. For ‘insurance' you can spray cleaned (and rinsed) cutting boards with a dilute bleach solution: 1 teaspoon bleach per quart of water. And it's best to have one cutting board dedicated to raw meat; another that is used for cooked meat and fresh fruits and vegetables.
XCutting sheets. Saran Disposable Cutting sheets haven't proven to be a satisfactory alternative to a cutting board. Better to buy an extra cutting board if you need to ‘take the show on the road.'
XVeggie washes. Maybe it was because so many people, like me, were unconvinced with the ‘data' showing that FIT ® Fruit and Vegetable Wash, by Proctor and Gamble, improved the safety of fresh fruits and vegetables. A close look at the data, that P&G provided, indicated that the experiments that they performed to show the superiority of their product just didn't match with the type of produce we would find in the grocery store. P&G has discontinued manufacture of this item.
?Antibacterial soap . Are antibacterial soaps and scrubs better than plain soap and water? It's hard to tell. While some consumers may benefit from using antibacterial soaps, specifically in those homes where an individual is under medical care, for most of us plain soap and warm water (with a 20 second scrub) will do just fine. There's also the issue of the potential for bacteria to develop resistance to the antibiotics that are in antibacterial soaps, toothpastes, and scrubs. So, until more information is available, it's best to stick to plain soap and water.
Mattick, et al. 2003. The survival of foodborne pathogens during domestic washing-up and subsequent transfer onto washing-up sponges, kitchen surfaces and food. International Journal of Food Microbiology. 85:213-226.
Home is Where the Germ Is. Nutrition Action Health Letter January/February 2004. p.9-11.
Dixon , B. 2004. Biocides in the kitchen. ASM News .
70:4-5.
R ecipe directions often say to cook a food until "done." But, what is "done?" While we worry about cooking a food long enough for safety, we also should be concerned about cooking food too long so that it no longer tastes good. You can assure 100% safety if food is cooked until it tastes and looks like cardboard, a piece of shoe leather or a hockey puck – but no one will eat it! Besides a safe temperature, another aspect of "doneness" has to do with our perception of the appearance, texture and optimum flavor of a food. The University of Nebraska has developed a food safety campaign aimed at encouraging proper cooking as a way to prepare food that is both safe and good tasting. This might be a nice resource for a summer newsletter article that you need to prepare. This information is located on the web: http://lancaster.unl.edu/food/ftfeb04.htm
Fingernails
as a Source of Germs
Compared with other parts of the hand, the area beneath the firngernails harbors the most microorganisms and is the most difficult to clean! Handwashing has long been recognized as an important step in preventing illness. But even when hands are washed, microbes can still remain beneath fingernails. Fingernail length and texture can also affect how easy it is to remove germs that might be hiding there. Scientists at the University of Georgia set out to determine the best way to remove bacteria and viruses from natural and artificial fingernails of different lengths.
Study design. Volunteers with artificial fingernails (8 women) or natural nails (5 men and 5 women) participated in the study. Most of the volunteers with natural fingernails trimmed their fingernails every 2 to 3 weeks; the male volunteers tended to trim their nails as short as possible, females did not. Volunteers with artificial nails generally wore them for more than 1 month. To complete the study, scientists contaminated the area under the volunteers' fingernails with bacteria or virus, and volunteers then washed their hands as follows: volunteers wet their hands briefly, and then a squirt (1 milliliter) of soap was placed on each hand. Next, volunteers rubbed their hands vigorously for 15 seconds and then rinsed with warm water for 10 seconds. They used two paper towels to dry their hands, and then the scientists took samples to see how effective the handwashing had been. The washing treatments were:
• tap water
• regular liquid soap
• antibacterial liquid soap
• alcohol-based hand sanitizer gel (used without water)
• regular liquid soap followed by alcohol gel
• regular liquid soap plus a nailbrush
Results. Washing with regular soap and scrubbing with a nailbrush (10 firm strokes with a brush per nail) was the most effective at removing germs. Using the alcohol-based hand sanitizer gel was least effective. The volunteers with artificial nails had more germs under their fingernails both before and after all the washing treatments. The number of germs was also associated with fingernail length, with more microbes found beneath longer fingernails. The scientists concluded that the best practice for food handlers is to maintain short fingernails, and to scrub fingernails with soap and a nailbrush when washing hands. (Source: Lin, et al. 2003. J. Food Protection. 12: 2296-2301.)
For many of you, deadlines for newsletter or other items that you need to prepare come earlier than the first of a given month (maybe the middle of the previous month, and so forth.) Because Easter is coming up rather early in April, the 11 th , I wanted to remind you of some resources that are available if you need ideas for newsletter articles, press releases, etc focused on spring/Easter.
• News Releases –Easter egg safety, etc http://www.cft.uwex.edu/ces/news/
• Food Facts for You! back issues (look under E aster for article related to this holiday) http://www.wisc.edu/foodsafety/wffoodfactsforyoubackissues.htm
• American Egg Board – food safety articles http://www.aeb.org/
Canned items: Toss or Keep? With spring cleaning just around the corner (or already here), here are some questions to help you evaluate canned items that might have been hanging around your basement for the last few years.
• Safety? Commercially canned items, or those that are home-canned following research-tested recipes, will remain safe almost indefinitely . Once the contents are placed into a vacuum-sealed container and properly processed, there will be no growth of microorganisms (assuming that storage conditions are reasonable for the product).
• Quality? Even though canned goods may remain safe almost indefinitely, the quality will deteriorate over an extended period of time. Even though safe, the texture of canned items will change over time and there will be loss of vitamins on extended storage. For home-canned items , we recommend that you consume those within a year of processing. This makes room for new canned goods on the pantry shelf when the garden is overflowing with produce yet again. Some individuals find it helpful to label and date jars of home-canned food as they inspect the jars and place them on the pantry shelf. The quality of items canned in glass jars can be extended by storing these jars in a cool, dry location out of direct sunlight. Many commercially canned items do not have a date stamped on the product indicating the expected shelf life. So, with commercially canned items, it's often best to rotate canned items, bringing the old cans to the front of a shelf or cupboard so that they are used up first. Consider the date of purchase, and use commercially canned items within one year from purchase.
• When in doubt, throw it out! All of us in Extension know this saying, and it applies to canned foods, as well as casseroles and other food items. If you aren't sure how old some food items are, but you are thinking it must be 3-5 years since you saw that brand of canned corn in the store, consider discarding the old cans and starting over. I personally don't recommend that you send all old canned items to your local food pantry, but suggest that you consider a donation of new cans or, better yet, a check so that the pantry can purchase what it needs. And remember, we suggest that pantries NOT take any home-canned items. We do not have any training programs in place at this time that would allow home-canned items to ‘fit' within guidelines for acceptable food for food pantries.