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UC Food Safety
University of California
UC Food Safety

UC Food Safety Home

Research and Extension faculty at UC Davis, Drs. Linda Harris and Trevor Suslow, welcome you to the University of California Food Safety website. Link to presentations, publications, and websites related to the production, harvest and processing of foods. The emphasis is microbial food safety but food biotechnology, food quality, and food security are also addressed.

Newly Added to Website - updated April 2016

Activity-Specific Food Safety Information

Agricultural Water

Agricultural Water and the Produce Safety Rule

The Produce Safety Rule (PSR) requires growers to initially establish a Microbial Water Quality Profile (MWQP) for each agricultural water source and conduct annual surveys for that water source in subsequent years. The water quality profile is based on the levels of generic E. coli in your agricultural water. There are different requirements for agricultural water that comes from surface or ground (well) sources.

More information on the Produce Safety Rule and agricultural water can be found here:
www.fda.gov/Food/GuidanceRegulation/FSMA/ucm334114.htm

Untreated Surface Water:

The initial MWQP must be established with a minimum of 20 water samples collected as close to harvest as possible over a period of at least 2 to a maximum of 4 years. Geometric mean (GM) and Statistical Threshold Value (STV) are calculated from these 20 samples (minimum). The GM and STV are your MWQP and should be compared to the microbial quality criteria provided in the Produce Safety Rule.

These tools were developed to make it easy to calculate the GM and STV and to determine if your water meets the standards for unrestricted application to produce before harvest. The tools were also designed to assist you with making food safety management decisions if your water does not meet the standards in the proposed rule.

Untreated Ground Water:

The initial MWQP must be established with a minimum of 4 water samples collected as close to harvest as possible over a growing season or over a period of one year. Geometric mean (GM) and Statistical Threshold Value (STV) are calculated from these 4 samples. The GM and STV are your MWQP and should be compared to the microbial quality criteria provided in the Produce Safety Rule.  After the initial MWQP has been established, GM and STV values must be updated annually based a minimum of 1 new sample. “Rolling” GM and STV values are calculated by combining the old and new sample data. The one new sample combined with the most recent 3 samples from the previous MWQP are used to update the MWQP and confirm that the water is still being used appropriately.

Tools to calculate Geometric Mean and Statistical Threshold Value:

Several tools were developed to make it easy to calculate the GM and STV and to determine if your water meets the standards for unrestricted application to produce before harvest. The tools were also designed to assist you with making food safety management decisions if your water does not meet the standards in the proposed rule.

Untreated Surface Water:

Untreated Ground Water:

Links are also available on the UA Fresh Produce Safety website  

Added December 2015

Food safety information for nuts and nut products - all updated 12-08-15

Added November 2015

 

UC Food Blog

Check foods with a thermometer to be sure they are fully cooked. Can you serve up a safe barbecue?
Posted 4/29/2016 - April showers bring May flowers, along with barbecue season! The season's warmer weather makes it a great time to be outdoors, but it also means there are increased food safety risks with the higher temperatures. Follow these tips to prepare, cook, and...

My-Healthy-Plate UC’s My Healthy Plate article named 'paper of the year'
Posted 4/27/2016 - The USDA's colorful MyPlate icon clearly shows many Americans how to formulate healthy meals for their families with the proper proportions of fruits and vegetables, protein foods, grains and dairy products. However, UC Cooperative Extension nutrition...

Site Creation date 6/1/2009
Webmaster for site:  Zann Gates

Webmaster Email: zgates@ucdavis.edu