Posts Tagged: food safety

Winter season: A time for food safety systems re-evaluation and education for food hubs

The holiday meal season is often a busy time for food hubs – entities that handle the aggregation, distribution and/or marketing of source-identified regional food – as restaurants, retailers and consumers fill their tables and shelves with an abundance of fresh, local products. However, the subsequent winter months can provide a valuable time for reflection and re-evaluation of a food hub's systems and processes. In this spirit, it may be helpful to remind people working at food hubs that University of California Sustainable Agriculture Research and Education Program (UC SAREP)  offers a suite of food-safety resources – in English and in Spanish – on its website. 

Educational resources include: 

• A step-by-step guide for food hubs on how to pursue a third-party food safety audit with guidance on how to navigate buyers' questions.
• Two sample food-safety plans intended as a starting point to be adapted to a food hub's specific operations and practices.
• Example standard operating procedure, or SOP, documents related to 11 common tasks carried out by food hubs.

“We hope these resources can play a role in helping food hubs to adopt best practices and control risks related to food safety,” says Gwenael Engelskirchen, sustainable food and farming coordinator with UC SAREP,  who led the development of these educational tools. 

According to the Centers for Disease Control and Prevention, approximately, 1 in 6 Americans (or 48 million people) gets sick and 3,000 die of foodborne diseases annually. In 2011, to help prevent the occurrence of foodborne illness, the federal government enacted the Food Safety Modernization Act (FSMA), designed to outline actions to be taken at various points along the supply chain for both human and animal food. 

UC SAREP's Food Safety Resources for Food Hubs are intended to help food hubs navigate these food-safety regulations and accompanying best practices. Resources are also available in Spanish at Recursos de seguridad alimentaria para los centros de distribución de alimentos. 

Food safety certification guide

Some buyers verify a supplier's food safety program by requiring an audit performed by a third-party certification body or auditing company. This Guide to Food Safety Certification offers key considerations before deciding to pursue a food safety audit and helps users navigate the food safety certification process. 

Food safety plan

Food hubs that meet the criteria for full compliance with FSMA's Preventive Controls for Human Food Rule are required to have a food-safety plan in place. And for all food hubs, having a shared document describing the facility's operations and how potential risks of food contamination are managed is a good idea. Two sample food safety plans, inspired by the operations of food hubs in California, provide a starting point and can be adapted to a hub's own operations. 

Standard operating procedures

Standard operating procedures provide detailed step-by-step instructions for how to carry out operational tasks within a food facility. The standard operating procedure samples cover common topics such as handwashing, facility cleaning and more, and are intended to be adapted to a food hub's specific operations and practices. 

Jacob Weiss from Spork Food Hub in Davis said, “the templates were a great starting place for us to build the framework of our food safety plan. It helped us figure out what we needed to (and didn't) need to include. I think the SOPs are also really useful because they are broad enough to get you started but flexible enough to add the specific practices of your business or hub.”

For additional information, visit UC SAREP's webpages on Food Safety Resources for Food Hubs or Recursos de seguridad alimentaria para los centros de distribución de alimentos. 

These resources and tools were developed in collaboration with various project partners, including Department of Food Science and Technology at UC Davis, Department of Population Health and Reproduction at UC Davis School of Veterinary Medicine, Center for Precision Medicine and Data Science at UC Davis Health, and Community Alliance with Family Farmers.

USDA awards $2 million to study livestock grazing in organic orchards

UC, The Organic Center, University of Rhode Island partner on $3.5m food-safety study for organic produce growers

Grazing sheep and other livestock can help convert cover crops to fertilizer for orchard crops. To develop best management practices, the University of California and The Organic Center are collaborating on research to help organic orchard growers safely incorporate livestock grazing into their farming practices. The project is funded by a $2 million grant recently awarded through the U.S. Department of Agriculture's Organic Agriculture Research and Extension Initiative research program.  

Interest in grazing livestock on cover crops in nut orchards has increased in recent years. However, research is needed to determine the best way to improve soil health and pest suppression, and to address concerns about food-borne pathogens and food safety.   

“Organic farmers typically follow the USDA National Organic Program standards for raw animal manure, waiting 90 to 120 days between incorporating raw manure into the soil and harvesting the crop,” said Alda Pires, UC Cooperative Extension urban agriculture and food safety specialist in the School of Veterinary Medicine at UC Davis.

“Little research has been conducted to verify adequate waiting periods to reduce contamination risks in integrated crop-livestock production systems,” she said. “This research will fill the knowledge gap and facilitate the development of science-based food safety guidelines for grazing small ruminants in orchards.” 

For this four-year project, “Influence of Orchard Grazing on Soil Health and Pest Control While Mitigating Food Safety Risk,” the scientists will study organic almond, walnut and pistachio orchards in two distinct nut-growing regions in California – the Sacramento Valley and San Joaquin Valley. The scientists will assess the effects of livestock grazing of cover crops on bacteria populations, soil health, pest control and economics.

Building soil health 

“Growers have consistently raised the need for more information on grazing impacts on nutrient availability during tree growth, as well as potential to build up the biological, physical and chemical pillars of soil health,” said Amelie Gaudin, associate professor and endowed chair of agroecology in the UC Davis Department of Plant Sciences.

Livestock grazing may provide an opportunity to quickly enhance the amount of nitrogen that can be used by plants and microbes when the cover crop is terminated. “This project will help growers develop nitrogen budgets for these more diversified systems and quantify additional benefits and potential tradeoffs for soil health – such as compaction and salinity – to guide the development of place-based best management practices,” Gaudin said.   

Pest management 

Houston Wilson, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside, will be studying the effects of livestock grazing on orchard pests.

“Navel orangeworm, or NOW, is by far the most destructive pest of almonds and pistachios,” Wilson said. “These moths overwinter in unharvested nuts in the orchard, and so removal and destruction of remnant nuts over the winter is the foundation of NOW control. While farmers typically use machinery to do this, grazing with animals may present a unique alternative that is more cost-effective and provides additional ecosystem benefits, such as soil health and weed control.” 

Outreach to farmers

As part of the project, The Organic Center was awarded $75,000 to work with UC Agriculture and Natural Resources to direct national extension and education outreach activities. These will include a social media campaign, webinars and educational sessions and a technical report for growers.  

“There is an increasing interest from organic farmers to learn how to incorporate livestock into their operations to gain better soil health and fertility,” said Amber Sciligo, director of science programs at The Organic Center.  

“This research is very exciting because it will holistically explore the potential risks and benefits of livestock not just to soil health, but also pest control – a truly interdisciplinary project that matches the whole system of the organic farm.” 

Produce food-safety management tools 

For another organic food-safety project, Pires and Sciligo will be working with Patrick Baur, professor of Sustainable Agriculture and Food Systems at the University of Rhode Island.

The University of Rhode Island and The Organic Center received $3.5 million from USDA's Organic Agriculture Research and Extension Initiative research program for the new organic food-safety education project. 

“We're going to develop a new food safety management tool designed specifically for organic soil amendments,” said Baur, who is leading the project. “We're also going to develop a suite of new communication and training tools aimed at the entire fruit and vegetable sector to build a shared language between organic agriculture and the food safety community and help them work better together.”  

As part of the produce project, Pires of UC Davis was awarded $1.16 million to conduct a risk assessment and create a publicly accessible dashboard to meet the specific needs of organic growers operating at different scales, under different cropping systems, in different regions.

Also participating in this project will be Beatriz Martinez Lopez, professor in the School of Veterinary Medicine at UC Davis, and Abhinav Mishra and Govindaraj Dev Kumar of the University of Georgia.  

New approaches to using polyacrylamide (PAM) to reduce sediment and sediment bound pesticides and nutrients in runoff and improve chlorine efficacy: Part II—an auger applicator for treating irrigation runoff in farm ditches

Minimizing suspended sediments in irrigation runoff is desirable for several reasons.  For growers reusing tailwater for watering their crops, they must assure that the water has minimal food safety risks by testing it for generic E coli and/or treating it with chlorine.  The concentration of free (or reactive) chlorine is reduced when tailwater contains a high concentration of suspended sediments.  Treating a large volume of tailwater with chlorine can be a significant expense over a season so it is important to be able to remove as much of the suspended sediments as possible before treatment.  

A second reason is that water quality regulations under Agriculture discharge Order 4.0 requires tailwater discharged into public water ways to not be toxic to aquatic organisms.  Pesticides that strongly bind to soil, such as pyrethroids, are carried on the suspended sediments in runoff which can cause toxicity to aquatic organisms that live in creeks and rivers downstream from farms.  Also, particulate forms of N and P which bind with the suspended sediments pose a water quality risk to receiving waterbodies such as the sloughs and wetlands along the coast. Both nutrients can spur algal blooms which reduces dissolved oxygen available to fish and other aquatic organisms.  

In a previous article we discussed a new approach to using Polyacrylamide (PAM), an inexpensive polymer molecule for reducing soil erosion, to treat sprinkler water.   This practice uses a specialized applicator (Fig. 1) to condition water flowing from a well with PAM.  An advantage of this method is that the cartridges in the applicator release a small amount of PAM (1 to 2 ppm) into the irrigation water, which flocculates soil particles that could potentially become suspended and transported in runoff.  Field tests using a prototype version of this applicator resulted in about 90% less suspended sediment in the tailwater when treated with PAM compared to untreated irrigation water.

Auger ditch applicator

A second approach we developed for reducing suspended sediment in runoff is to use a smart applicator that can automatically apply dry PAM to the runoff water flowing in farm ditches.   This type of applicator is suspended on a platform above a ditch and uses a hopper filled with dry PAM and an auger system controlled by an electric motor and small computer to drop PAM down a tube into the flowing runoff (Fig. 2).   A weir and float mechanism located upstream are used to monitor the flow rate of the runoff so that the computer can adjust the frequency that PAM is applied.   A video at this link demonstrates how the auger applicator operates.

Field testing of the ditch applicator

A yearlong study at a commercial farm showed that the ditch applicator was effective in removing 98% of the suspended sediments transported in runoff (Table 1, Fig. 3).  Based on the total runoff measured in a single drainage ditch during the 2022 season (21.5 acre-feet), an estimated 106 tons of sediment were removed (Fig. 4). 

Turbidity in the runoff was reduced by more than 99%, and Total P and N were reduced on average by 89% and 60%, respectively, during the season (Table 1, Figs. 5 and 6).    These reductions in nutrient load, suspended sediment, and turbidity could greatly improve water quality in water bodies downstream from farms that discharge irrigation runoff.  

 

Table 1.  Average concentration of N, P, and sediments carried in irrigation runoff before (upstream) and after (downstream) treatment with the PAM ditch applicator (April – October 2022). Average of 32 paired grab samples from 3 farm ditches.  Downstream locations varied from 300 to 500 ft downstream from the PAM applicators.

 

 

 

 

Ditch applicator vs well applicator

Although more effective at reducing suspended sediment in runoff than the well applicator, the ditch applicator required more maintenance.   PAM needed to be added to the hopper once or twice per week during the irrigation season, and sediment that settled in the ditches had to be cleaned out periodically using a backhoe.  Also, removed sediment had to be spread back in the fields.    The well applicator only required periodic refilling of the cartridges with PAM, and minimizes the amount of sediment that settles out in the drainage ditches.

PAM effects on chlorine requirement

To evaluate the effect of PAM on the quantity of chlorine needed to treat runoff, we performed a laboratory assay on samples of sprinkler runoff collected upstream and downstream of one of the ditch applicators.   The turbidity of the upstream (untreated) and downstream samples (PAM treated) was 2276 and 9.5 NTU, respectively. The electrical conductivity of the runoff samples was 1.35 dS/m and the pH was 8.4 before adding chlorine.  The main factors evaluated in the assay were sodium hypochlorite concentration and acidification with 10% sulfuric acid. Presumably, acidifying the runoff to a pH of 6.5 should increase the concentration of the more reactive form of chlorine, hypochlorous acid which is more effective as a microbial disinfectant.  Residual free chlorine concentration of the treatments was evaluated 2 and 4 hours after adding 12.5% sodium hypochlorite at concentrations ranging 12.5 to 31.3 ul per liter of runoff (100 to 250 ul of 12.5% NaOCl per L of water). 

The laboratory assay showed that reducing suspended sediment concentration using PAM increased the efficacy of chlorine treatment of runoff.  The free chlorine concentration for PAM treated runoff was more than twice the concentration measured in the untreated runoff for all sodium hypochlorite concentrations evaluated after 2 hours and more than three times the concentration after 4 hours (Fig. 7).  Free chlorine concentration in the PAM treated runoff was more than 2.5 ppm two hours after treatment at the lowest concentration of chlorine evaluated (12.5 ul/L) but was less than 0.5 ppm in the untreated runoff.  To attain similar chlorine efficacy as PAM treated runoff, untreated runoff would require twice as much sodium hypochlorite (25 ul/L).  These chlorine requirements would correspond to 26 and52 gallons of 12.5% sodium hypochlorite to treat and acre-foot of runoff with and without a PAM pretreatment, respectively.

Acidification of the runoff to a pH of 6.5 with sulfuric acid increased the free chlorine concentration in the PAM treated runoff at the highest concentration of sodium hypochlorite (31.3 ul/L) after 4 hours.  Acidification did not have a significant effect on free chlorine concentration for the other treatments.

 

 Summary

Both versions of the dry PAM applicators (well and ditch) show promise for greatly reducing soil erosion, as well as helping improve water quality and the efficacy of chlorine for treating tail water reused for irrigation.  By considerably reducing the concentration of suspended sediment in irrigation runoff, chlorine can be more effective as a disinfection agent, and better control E. coli and other microbial pathogens that could potentially cause public health risks. 

Acknowledgments:  We greatly appreciate assistance in fabricating the prototype PAM applicators from RayFab. This project was funded by the California Leafy Green Research Board. 

Further reading

Suslow, T. 1997. Postharvest Chlorination Basic Properties and Key Points for Effective Disinfection. UCANR Publication 8003.

Cahn, M., Chambers, D., Lockhart, T., Cabrera, N., 2022. New approaches to using polyacrylamide (PAM) to reduce sediment and sediment bound pesticides and nutrients in runoff: Part I--an applicator for treating pressurized irrigation water

Cahn, M., 2009. A Guide to Using Polyacrylamide (PAM) Polymers for Control of Irrigation Run-off on the Central Coast

Climate-Change Resources

University of California UC ANR Green Blog (Climate Change and Other Topics) https://ucanr.edu/blogs/Green/index.cfm?tagname=climate%20change (full index)

Examples:

     -  Save Trees First: Tips to Keep Them Alive Under Drought https://ucanr.edu/b/~CdD 

     - Landscaping with Fire Exposure in Mind: https://ucanr.edu/b/~G4D

     - Cities in California Inland Areas Must Make Street Tree Changes to adapt to Future Climate  https://ucanr.edu/b/~oF7

Drought, Climate Change and California Water Management Ted Grantham, UC Cooperative Extension specialist (23 minutes) https://youtu.be/dlimj75Wn9Q

Climate Variability and Change: Trends and Impacts on CA Agriculture Tapan Pathak, UC Cooperative Extension specialist (24 minutes) https://youtu.be/bIHI0yqqQJc

California Institute for Water Resources (links to blogs, talks, podcasts, water experts, etc.) https://ciwr.ucanr.edu/California_Drought_Expertise/

UC ANR Wildfire Resources (publications, videos, etc.) https://ucanr.edu/News/For_the_media/Press_kits/Wildfire/ (main website)

      -UC ANR Fire Resources and Information https://ucanr.edu/sites/fire/ (main website)

            -Preparing Home Landscaping https://ucanr.edu/sites/fire/Prepare/Landscaping/

UC ANR Free Publications https://anrcatalog.ucanr.edu/ (main website)

- Benefits of Plants to Humans and Urban Ecosystems: https://anrcatalog.ucanr.edu/pdf/8726.pdf

 -Keeping Plants Alive Under Drought and Water Restrictions (English version) https://anrcatalog.ucanr.edu/pdf/8553.pdf

  (Spanish version) https://anrcatalog.ucanr.edu/pdf/8628.pdf

-  Use of Graywater in Urban Landscapes https://anrcatalog.ucanr.edu/pdf/8536.pdf

-  Sustainable Landscaping in California https://anrcatalog.ucanr.edu/pdf/8504.pdf

 

Other (Non-UC) Climate Change Resources

Urban Forests and Climate Change. Urban forests play an important role in climate change mitigation and adaptation. Active stewardship of a community's forestry assets can strengthen local resilience to climate change while creating more sustainable and desirable places to live. https://www.fs.usda.gov/ccrc/topics/urban-forests

Examining the Viability of Planting Trees to Mitigate Climate Change (plausible at the forest level) https://climate.nasa.gov/news/2927/examining-the-viability-of-planting-trees-to-help-mitigate-climate-change/

Reports and other information resources coordinated under the auspices of the United Nations and produced through the collaboration of thousands of international scientists to provide a clear and up to date view of the current state of scientific knowledge relevant to climate change. United Nations Climate Action

Scientific reports, programs, action movements and events related to climate change. National Center for Atmospheric Research (National Science Foundation)

Find useful reports, program information and other documents resulting from federally funded research and development into the behavior of the atmosphere and related physical, biological and social systems. Search and find climate data from prehistory through to an hour ago in the world's largest climate data archive. (Formerly the "Climatic Data Center") National Centers for Environmental Information (NOAA)

Think tank providing information, analysis, policy and solution development for addressing climate change and energy issues (formerly known as the: "Pew Center on Global Climate Change"). Center for Climate & Energy Solutions (C2ES)

Mapping Resilience: A Blueprint for Thriving in the Face of Climate Disaster. The Climate Adaptation Knowledge Exchange (CAKE) was launched in July 2010 and is managed by EcoAdapt, a non-profit with a singular mission: to create a robust future in the face of climate change by bringing together diverse players to reshape planning and management in response to rapid climate change. https://www.cakex.org/documents/mapping-resilience-blueprint-thriving-face-climate-disaster

Cal-Adapt provides a way to explore peer-reviewed data that portrays how climate change might affect California at the state and local level. We make this data available through downloads, visualizations, and the Cal-Adapt API for your research, outreach, and adaptation planning needs. Cal-Adapt is a collaboration between state agency funding programs, university and private sector researchers https://cal-adapt.org/

Find reports, maps, data and other resources produced through a confederation of the research arms of 13 Federal departments and agencies that carry out research and develop and maintain capabilities that support the Nation's response to global change. Global Change (U.S. Global Change Research Program)

The Pacific Institute is a global water think tank that combines science-based thought leadership with active outreach to influence local, national, and international efforts to develop sustainable water policies. https://pacinst.org/our-approach/

Making equity real in climate adaptation and community resilience policies and programs: a guidebook. https://greenlining.org/publications/2019/making-equity-real-in-climate-adaption-and-community-resilience-policies-and-programs-a-guidebook/ 

Quarterly CA Climate Updates and CA Drought Monitor Maps (updated each Thursday) https://www.drought.gov/documents/quarterly-climate-impacts-and-outlook-western-region-june-2022

 

 

 

 

Drought focus of Water Resources IMPACT magazine special issue

UC ANR experts address emotional toll of drought

Preparing the American West for prolonged drought is the focus of a double issue of Water Resources IMPACT magazine. The California Water Commission staff are guest editors for this special open-access edition of the magazine, which is published by the American Water Resources Association.   

Faith Kearns, academic coordinator of University of California Agriculture and Natural Resources' California Institute for Water Resources, is among the authors delving into how drought impacts people and the environment and how we can better prepare for the inevitable. 

The first issue, published on Feb. 14, focuses on water scarcity issues confronting California and the ways these issues affect different sectors. 

In “Trauma, Care, and Solidarity: Addressing the Emotional Toll of Chronic Drought,” Kearns highlights the effects of drought on mental health. She points to the spike in suicide hotline calls when wells ran dry in Southeast Asian communities in California's Central Valley.

By listening to Southeast Asian farmers, Ruth Dahlquist-Willard and Michael Yang of UC Cooperative Extension were able to “lighten the load” for them by providing pragmatic support, Kearns writes.

“The scale of some of these highly emotional issues – drought, wildfires, climate change – can make them seem incredibly difficult, if not impossible, to deal with,” Kearns said. “At the same time, they are affecting everyone living in the western U.S. on a daily basis. I wanted to highlight and provide models based on work that people – whether they are researchers, clinical psychologists, or Cooperative Extension advisors – are doing right now to ease the way.”

The authors who contributed to the double issue are a diverse array of Tribal experts, academics, nongovernmental organization thought-leaders, water managers and water policy influencers, each of whom brings their own perspective on the topic of drought. Their expertise and perspectives in climate science, water policy and water management will help inform drought-related decision-making and support policies that better prepare the state to thrive during periods of prolonged water scarcity.

In addition to Kearns, the first issue includes articles contributed by:

• Samantha Stevenson, University of California, Santa Barbara
• Jay Lund, University of California, Davis
• Ron Goode, North Fork Mono Tribe
• Andy Fecko, Placer County Water Agency
• Jeff Mount, Public Policy Institute of California, and Ted Grantham, University of California, Berkeley/UC Cooperative Extension
• Nat Seavy and Karyn Stockdale, National Audubon Society
• Kjia Rivers, Community Water Center
• Cannon Michael, Bowles Farming
• Michelle Reimers, Turlock Irrigation District

The January/February edition of Water Resources IMPACT magazine can be accessed, free of charge, on the American Water Resources Association website at https://www.awra.org under “Publications.”

The second issue, to be published in March, will focus on drought response, considering the options for adaptation. This two-part series complements the Commission's work on strategies to protect communities and fish and wildlife in the event of a long-term drought.

 

 

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