Posts Tagged: food
Californians growing food in cities now have help understanding the food safety laws that apply to them. A free publication containing California-specific information on rules and regulations for urban farmers was recently published by the University of California Agriculture and Natural Resources.
Growing fresh fruits and vegetables in community gardens, backyards and rooftops helps provide more food for urban communities, creates jobs and teaches people about the value of healthy foods, according to Jennifer Sowerwine, lead author and UC Cooperative Extension specialist at UC Berkeley.
"There are a growing number of backyard and community producers who are scaling up to sell some of what they grow,” said Rachel Surls, UC Cooperative Extension sustainable food systems advisor based in Los Angeles County and co-author. “We hope this guide will help them navigate the regulations and learn best practices for keeping food safe for consumers."
“California Urban Agriculture Food Safety Guide” provides urban food producers with an overview of food safety laws and regulations that may impact their operations. To help minimize the risk of contamination of foods during their production and exchange, it also provides best practices, or Good Agricultural Practices (GAPs).
"People donating produce grown or gleaned from urban environments will learn what laws may apply to them, and practical steps they can follow to minimize the risk of foodborne illness from urban-produced foods,” Sowerwine said.
The 72-page guide covers fresh produce safety, urban soils safety, as well as food safety considerations for eggs, poultry and small livestock in the urban environment. The authors also point out which aspects of the Food Safety Modernization Act apply to urban farms, California laws that apply, record keeping requirements, information on working with gleaners, how to register as a community supported agriculture (CSA) organization, permitting requirements, and how to develop a food safety plan.
Urban farmers can do a food safety assessment of their own farms using a check list included in the publication.
The guide was produced by Sowerwine; Christina Oatfield, Sustainable Economies Law Center policy director; Rob Bennaton, UC Cooperative Extension urban agriculture advisor; Alda Pires, UC Cooperative Extension in the UC Davis School of Veterinary Medicine; Surls; Valerie Borel, UC Cooperative Extension program representative; and Andre Biscaro, UC Cooperative Extension agriculture and environmental issues advisor.
The publication “California Urban Agriculture Food Safety Guide: Laws and Standard Operating Procedures for Farming Safely in the City” is available for free download at https://anrcatalog.ucanr.edu/pdf/8660.pdf.
A new study by UC Davis researchers finds a low risk of contamination of foodborne pathogens on produce and meat at Northern California certified farmers markets, but still finds cause for some concern.
The study, published in the Journal of Food Protection, examined the prevalence of Salmonella on meat and produce, as well as the prevalence of generic E. coli on produce. Samples were taken from 44 certified Northern California farmers markets, including in the Sacramento region and Bay Area. Less than 2% (1.8%) of animal products sampled, including beef, pork and poultry, tested positive for Salmonella, while all produce samples tested negative. Slightly more than 30 percent (31.3%) of produce tested positive for generic E. coli. Generic E. coli is an indication of fecal contamination, but not all E. coli is harmful. This study didn't test for pathogenic E. coli.
“Based on this data, I think it's safe to consume meat and produce from farmers markets,” said lead author Alda Pires, a UC Cooperative Extension specialist and research scientist in the UC Davis School of Veterinary Medicine. “That's a low risk of contamination of foodborne pathogens, especially Salmonella.”
While the prevalence of generic E. coli may seem relatively high, the concentrations were low. Pires said that's especially so compared to previous studies of contamination at farmers markets elsewhere in the United States. The prevalence of Salmonella in meat sampled from Northern California farmers markets is also much lower than what previous studies have found in grocery stores.
Among the produce sampled, leafy greens had the highest prevalence of E. coli, followed by root vegetables.
Consumers should still be cautious
Consumers and farmers should still be aware that produce and meat were not free from contamination. Consumers need to make sure the foods they prepare from farmers markets follow the good hygiene practices recommended by Centers for Disease Control and Prevention. Consumers should also keep produce separate from meat to avoid cross-contamination.
“The study raises awareness that it's not just very large farms that can have contamination,” said co-author Michele Jay-Russell, with the Western Center for Food Safety at UC Davis. “Farmers need to pay attention to everything they're doing, from planting to storage, to avoid contamination.”
While certified farmers markets are inspected for food hygiene, microbiological quality is not explored. Smaller farms, those making less than $25,000 a year, are also exempt from certain food-safety provisions of the U.S. Food and Drug Administration's Food Safety and Modernization Act. Foodborne illness costs the U.S. economy more than $15 billion annually.
Other co-authors include James Stover, Esther Kukielka, Viktoria Haghani, Peiman Aminabadi and Thais De Melo Ramos of UC Davis. Research support came from the U.S. Department of Agriculture.
One of the many wonderful things about California's climate is that in many regions of the state you'll find orchards of walnut, almond, pecan, pistachio or chestnut trees. You may be growing or planning to grow one or more of these trees in your yard so you can enjoy consuming the nuts. But do you know how to safely store, and preserve these fresh nuts?
There are just a few simple steps to follow. First, be sure to promptly remove the hull (the fibrous outer covering) that may still be remaining on some of the nuts. (If you have hulled walnuts before you will know they'll stain your hands brown, so you should wear gloves to hull walnuts.)
During this time of COVID-19, you may be tempted to wash your fresh nuts, but don't. Washing the nuts in their shell could increase their moisture and provide the environment for mold or bacteria to grow. Although not required to safely store the nuts, to decrease the likelihood of walnuts, almonds, pecans and pistachios developing mold, you may want to dry them. For walnuts and almonds, spread them out preferably single layer on a flat screen or tray that allows good air circulation. To prevent birds and other critters from making off with them while they are drying, cover them with another screen or plastic netting. Stir and move the nuts around daily.
It will take several days for them to dry. To determine when they are sufficiently dry, remove the shell from several nuts. Break apart the almond kernels, or walnut meat. If they are rubbery, they're not dried sufficiently. If they are crisp or brittle when broken, then they are dried adequately.
For pecans, they should be dried slowly in air temperatures 75–85 degrees Fahrenheit to prevent the shells from cracking. A fan blowing on the nuts will speed up the drying process, which can take up to 10 days. The pecans are dry when they're brittle and the membrane between the kernel halves separate easily from the kernels.
Pistachios can be dried in the sun on a plastic tarp, or they can be dried in the oven at 140–160 degrees Fahrenheit for 10–14 hours. They are dried when the kernels are crisp, but not brittle.
Before consuming or storing at room temperature, fresh home-grown walnuts, almonds, pecans, pistachios or chestnuts, or those bought at farm stands, pasteurize them to kill any insects or insect eggs. To pasteurize, simply place them in the freezer for 48 hours. (Make sure your freezer is set at 0 degrees Fahrenheit or lower.)
To store your walnuts, almond, pecans or pistachios, place them in clean moisture free, odor tight packaging, such as glass or plastic jars or other containers. The nuts can be stored shelled or unshelled. They can be stored up to a year in your refrigerator set at 40 degrees Fahrenheit or lower. Almonds can be stored in your freezer (set at 0 degrees Fahrenheit or lower) for a year or more, walnuts and pecans for two years plus, and pistachios for three years.
Chestnuts are different from the other nuts because they're more like potatoes than tree nuts. They usually develop mold within two weeks if stored at room temperature. Unshelled chestnuts can only be stored for two to three months in the refrigerator, but shelled chestnuts can be stored for a year in the refrigerator. Both shelled and unshelled chestnuts can be stored in the freezer for one year or more.
Enjoy your stored nuts throughout the year!
For more information about the UC Master Food Preserver Program, including the Food Preservation Video Library, visit mfp.ucanr.edu.
A summer of smoke and ash in many parts of California has raised questions about the safety of produce growing on farms and in the garden, eggs laid by chickens who peck around in ash-laden areas, and remediation needed to safely and effectively grow food in the future.
UC Agriculture and Natural Resources brought together experts who have researched the effects of previous fires' fallout and studied soil contaminants to share their insight in a two-hour webinar now available on YouTube.
“The No. 1 health concern during a fire is smoke inhalation, and it's been well documented that wildfire smoke can negatively impact both the heart and the lungs,” said Claire O'Brien, a pharmacology and toxicology doctoral student at UC Davis. “However, the chemicals found in the smoke don't just stay in the air. They can deposit onto plants and into soil and water.”
Although every fire is unique, some generalizations can be drawn from research conducted following previous fires. UC Cooperative Extension food systems advisor Julia Van Soelen Kim detailed a study conducted following the October 2017 wildfires in Sonoma County and across the North Bay.
With the help of UC Master Gardener and community volunteers, the researchers collected over 200 samples of homegrown collard greens, lettuces, kale and chard that were exposed to wildfire smoke and ash. A subset of the samples were analyzed by a private laboratory.
“There was very low concern about chemicals on produce,” Van Soelen Kim said. “No samples had detectable levels of lead, arsenic, mercury or chromium. And that's a huge sigh of relief.” However, analytical results vary by site, site history and by fire event, and few have pre-fire baseline data to compare with.
Van Soelen Kim said basic food-safety practices should be followed when preparing to eat food grown in a home garden, regardless of ash or smoke contamination.
“You should always wash your hands before and after harvesting, and wash your produce in running water to mitigate any kind of potential risk,” she said.
Are backyard chicken eggs safe to eat?
Another study outlined at the webinar used a similar process to determine whether there might be contaminants in the eggs laid by backyard poultry that live and feed in areas exposed to wildfire ash and smoke.
Scientists know from previous research that chickens exposed to lead in their environment can produce eggs with high lead content and that heavy metal content of ash from urban wildfires is higher than from rural wildfire.
“We combined those two pieces of research with what we know that chickens do all day: they peck at the ground for hours on end,” said Todd Kelman, a veterinarian in the School of Veterinary Medicine at UC Davis. “That makes for a pretty good hypothesis that urban wildfire could pose a risk for the production of eggs and poultry that contain heavy metals.”
Kelman and his team put out a call for eggs from backyard poultry and received samples from 344 premises in fire-affected and non-fire-affected areas of California.
Surprisingly, egg samples that contained higher lead levels came from parts of the state that were not directly impacted by ash and smoke.
“Did our data support our hypothesis that proximity to urban wildfire is a driving source for lead in eggs of backyard poultry? The answer is not so much,” Kelman said. “So, is it safe to eat eggs from your backyard poultry? We can't give you a definitive answer to that question. But we do suggest you assess your risk and reduce the risk of contamination.”
Practices that reduce the risk include keeping chickens off the ground, using a chicken feeder that prevents spillage onto the ground and making calcium readily available, for example in the form of oyster shells, because calcium can prevent the absorption of lead. Making sure that chickens are provided uncontaminated water is also an important part of risk reduction.
For confirmation on the safety backyard chickens and their eggs, lab tests for eggs are available for $60 from the California Animal Health and Food Safety Laboratory at UC Davis, or chickens may be submitted to CAHFS for necropsy.
Are soils safe for growing food after a fire?
Fire effects on soil is another consideration in burned areas, said UC Cooperative Extension urban agriculture advisor Rob Bennaton.
“Fires heat topsoil layers. They reduce the amount of living micro-organisms at the site of the burn, and also affect organic matter and nutrients. Ash deposits over time may make soils more alkaline,” he said. “As a result of these combined factors, there are temporary changes in nutrient levels and the capacity for soils to exchange nutrients for optimal plant growth and nutrition.”
With proper land care and management, soils can be remediated over time.
“It won't happen overnight. Soils were developed over millions of years,” he said.
Some ways to improve safety when gardening in fire-affected areas including keeping the soil covered with wood chips or other landscape mulch to reduce airborne soil dust. Use drip irrigation to prevent up splash onto the undersides of growing vegetables. Promote good drainage, especially at the bottom of slopes to prevent the concentration of contaminants.
Lab tests are often needed to determine the soils' post-fire characteristics. “Don't guess, but test,” Bennaton said.
The UC Master Gardener Program can provide technical assistance to help home gardeners find resources for home soil testing, he said.
Additional resources and information shared during the webinar include:
Post-fire soil resources and soil testing information
- UCCE publication on Soils in Urban Agriculture with soil testing & sampling information
- The UC ANR Healthy Soils Website, which has many resources worth reviewing.
- Tips for Interpreting Soil Analysis
- UC Master Gardener of Sonoma County 2018 workshop video “Effects of fire on soil”
Post-fire food safety
- Research on produce safety and backyard chicken egg safety after the 2017 wildfires in California is available on this web page. To view a past webinar recording with these research findings, click this link.
- Poultry wildfire resources from the UC Davis School of Veterinary Medicine:
- Best Practices for Produce Safety After Fire
- Understanding Risk: A community guide for assessing the potential health impacts of locally grown produce exposed to urban wildfire smoke
Firewise and sustainable home landscaping design in the defensible space zone
- Visit the UC Master Gardener Program of Sonoma County firewise landscaping web page.
- For a recent firewise & sustainable design and maintenance video by the Resilient Landscapes Coalition.
Impact of smoke & ash on plants
Air drying peppers can be a fun activity to do with children. For the best results, select only firm, fresh peppers free of any blemishes or other damage. Wash them thoroughly. Then use a knife to cut a slit in the stems. Using a large crafting needle, thread light string or a heavy thread through the stems of the peppers. Hang the string of peppers in a well-ventilated room since high humidity can cause the peppers to spoil. The peppers should dry within about four weeks.
Peppers can also be sun dried. Drying peppers in the sun requires a minimum temperature of 90°F for several days, with a humidity level below 60 percent. To sun dry peppers, first rinse them to remove any dirt. Then lay them on screen trays made of stainless steel, plastic, or Teflon coated fiberglass. Do not use galvanized metal, copper or aluminum screens. Place the trays on blocks to increase airflow and cover the peppers with cheesecloth to protect them from birds and insects. Once the peppers are dried, pasteurize them to kill any insect or insect eggs that may have gotten on the peppers. To pasteurize them, either seal them in a freezer bag and place the bag in the freezer (set at 0°F or below) for 48 hours, or lay the peppers out single layer on a tray and place them in the oven pre-heated to 160°F for 30 minutes.
If you have an electric food dehydrator, first thoroughly rinse the peppers and remove the stems and cores. Cut the peppers into 3/8-inch disks and place in a single layer on the dehydrator trays. The peppers generally take 8 to 12 hours to dry in a dehydrator.
You can also dry peppers in your oven, although you may not want to heat up your house using this method in the summer. To dry peppers in your oven, first make sure your oven can be set to 140°F. (Any higher temperature will cook, not dehydrate the peppers.) Place washed peppers single layer on an oven drying tray (note: cake cooling racks placed on a cookie tray work well). Make sure the drying tray clears all sides of the oven three to four inches. If you are placing more than one drying tray in your oven, make sure they're spaced two to three inches apart for air circulation. The oven door needs to be propped open two to six inches during the entire drying process. You can place an oven thermometer near the drying tray to get an accurate temperature reading and adjust the temperature as needed to reach 140°F. Since oven drying takes about twice as long as an electric food dehydrator, it will take approximately 16 to 24 hours to dry peppers using this method. Just be sure to let the peppers completely cool before packaging them for storage.
Dried peppers can be stored for several months in a cool dark place. They should be stored in moisture proof packaging such as a glass jar or freezer container. Plastic freezer bags can be used but be aware that they are not rodent proof. Rehydrate dried peppers for use in dishes like casseroles by soaking them in water. Or you may opt to crumble or turn the dried peppers into a powder to use as a seasoning.
Source of information and more reading:
For more information on drying peppers, see Peppers: Safe Methods to Store, Preserve and Enjoy from the University of California Division of Agriculture and Natural Resources accessible at https://anrcatalog.ucanr.edu/pdf/8004.pdf and Preserving Food: Drying Fruits and Vegetables from the University of Georgia Cooperative Extension Service accessible at https://nchfp.uga.edu/publications/uga/uga_dry_fruit.pdf.
For more information about the UC Master Food Preserver Program, including the Food Preservation Video Library, visit mfp.ucanr.edu.