Food Safety and Strawberries Trevor Phister, PhD Assistant Professor Department of Food Science [email_address]

Why Should We Care? Every year foodborne illnesses result in an estimated: 76 million cases of foodborne illness. 325,000 people hospitalized for foodborne illness. 5,200 needless deaths each year. Economic losses between 10-83 billion dollars.

Every year foodborne illnesses result in an estimated:

76 million cases of foodborne illness.

325,000 people hospitalized for foodborne illness.

5,200 needless deaths each year.

Economic losses between 10-83 billion dollars.

Produce Associated Outbreaks Affect Business Strawberry industry lost an estimated $50 million in 1996 after mistakenly being indicated as the source of pathogens in an outbreak. Odwalla shareholder value dropped approximately 41% ($12.4 million) in six months after outbreak. Work against produce promotions campaigns. May result in unwanted legislation or regulation.

Strawberry industry lost an estimated $50 million in 1996 after mistakenly being indicated as the source of pathogens in an outbreak.

Odwalla shareholder value dropped approximately 41% ($12.4 million) in six months after outbreak.

Work against produce promotions campaigns.

May result in unwanted legislation or regulation.

Microbes That Cause Foodborne Illness Bacteria – Single-celled organisms that live independently. Viruses - small particles that live and replicate in a host. Parasites - intestinal worms or protozoa that live in a host animal or human. Parasites Viruses Bacteria

Bacteria – Single-celled organisms that live independently.

Viruses - small particles that live and replicate in a host.

Parasites - intestinal worms or protozoa that live in a host animal or human.

Number of Produce Associated Outbreaks by Decade, 1973 - 1997 3.7 6.5 10.5 0 2 4 6 8 10 12 1973-79 1980-89 1990-97 Decade Outbreaks / year

Main produce items Leafy greens Tomato Sprouts Berries Melons

Leafy greens

Tomato

Sprouts

Berries

Melons

Harmful Microorganisms & Outbreaks Associated with Produce l f a s p r o u t s , r o o t v e g e t a b l e s , d r i e d s e a w e e d L m o n o c y t o g e n e s C a b b a g e B . c e r e u s S p r o u t s H e p a t i t i s A v i r u s I c e b e r g l e t t u c e , r a s p b e r r i e s , s t r a w b e r r i e s C r y p t o s p o r i d i u m A p p l e c i d e r C y c l o s p o r a R a s p b e r r i e s P a t h o g e n P r o d u c e E . c o l i O 1 5 7 : H 7 I c e b e r g l e t t u c e , r a d i s h s p r o u t s , u n p a s t e u r i z e d a p p l e c i d e r / j u i c e S a l m o n e l l a s p p . T o m a t o e s , b e a n s p r o u t s , s l i c e d w a t e r m e l o n , s l i c e d c a n t a l o u p e , c o l e s l a w & o n i o n s , a l f a

Frequency of Pathogens on Produce Vegetables (from literature): Salmonella 1- 8% L. monocytogenes 2- 30% Shigella 1% No difference was found between organic and conventional FDA Produce Surveillance Program Imports - 4% positive rate ( Salmonella & Shigella ) Domestic - currently being conducted

Vegetables (from literature):

Salmonella 1- 8%

L. monocytogenes 2- 30%

Shigella 1%

No difference was found between organic and conventional

FDA Produce Surveillance Program

Imports - 4% positive rate ( Salmonella & Shigella )

Domestic - currently being conducted

The Problem Charles Dharapak/Associated Press

Strawberries 1992 Hepatitis A 35 infected 1997 2.6 million pounds frozen strawberries recalled Thousands of children exposed to Hepatitis A 262 children infected

1992 Hepatitis A

35 infected

1997

2.6 million pounds frozen strawberries recalled

Thousands of children exposed to Hepatitis A

262 children infected

What can we do?

Taken up through roots JFP vol65 p18-23

Solutions

Washes and rinses Chlorine Chlorine dioxide Ozone Acetic acid Electrolized water

Chlorine

Chlorine dioxide

Ozone

Acetic acid

Electrolized water

Good Agricultural Practices

Good agricultural practices Water Fertilizer Animal feces Worker health and hygiene Field sanitation Packing facility Transportation Traceback

Water

Fertilizer

Animal feces

Worker health and hygiene

Field sanitation

Packing facility

Transportation

Traceback

Good management practices Growers and packers who successfully pass will be listed on the USDA and NCDA web site Participation is voluntary Program initiated by retailers asking for demonstration of adherence to food safety practices http://www.ncagr.com/markets/gradnreg/foodsafety/index.htm Phone: (252)-792-1672

Growers and packers who successfully pass will be listed on the USDA and NCDA web site

Participation is voluntary

Program initiated by retailers asking for demonstration of adherence to food safety practices

http://www.ncagr.com/markets/gradnreg/foodsafety/index.htm

Phone: (252)-792-1672

Good management practices

Good agricultural practices Water Fertilizer and animal feces Worker health and hygiene Field sanitation Packing facility Transportation Traceback

Water

Fertilizer and animal feces

Worker health and hygiene

Field sanitation

Packing facility

Transportation

Traceback

water Anytime water comes in contact with fresh produce, its quality determines the potential for pathogen contamination since water may be a carrier of a number of types of microorganisms: Escherichia coli , Salmonella spp., Vibrio cholerae , Shigella spp, Cryptosporidium parvum , Giardia lamblia , Cyclospora cayetanensis , Toxisplasma gondii , the Norwalk virus and hepatitis A Courtesy of FDA Courtesy University of Florida

Anytime water comes in contact with fresh produce, its quality determines the potential for pathogen contamination since water may be a carrier of a number of types of microorganisms:

Escherichia coli , Salmonella spp., Vibrio cholerae , Shigella spp, Cryptosporidium parvum , Giardia lamblia , Cyclospora cayetanensis , Toxisplasma gondii , the Norwalk virus and hepatitis A

Usually, water for agricultural uses comes from: Surface sources such as rivers, streams, irrigation ditches and canals Reservoirs (open or capped) Municipal water systems water Courtesy of FDA Courtesy University of Florida

Usually, water for agricultural uses comes from:

Surface sources such as rivers, streams, irrigation ditches and canals

Reservoirs (open or capped)

Municipal water systems

Make sure you know your water system

Ground water may be contaminated by a variety of biological and chemical hazards, which include: Bacteria and viruses Domestic waste Nitrate nitrogen Synthetic organic chemicals Heavy metals Petroleum residues Combustion products from roadways Courtesy of FDA

Bacteria and viruses

Domestic waste

Nitrate nitrogen

Synthetic organic chemicals

Heavy metals

Petroleum residues

Combustion products from roadways

Microbiological Testing Microbiological testing is used in the verification steps of a safety assurance program. It is important to document the frequency and results of each water test for comparison purposes. These records would become very important in the event of a microbiological outbreak investigation. Courtesy of FDA Courtesy University of Florida

Microbiological testing is used in the verification steps of a safety assurance program.

It is important to document the frequency and results of each water test for comparison purposes.

These records would become very important in the event of a microbiological outbreak investigation.

Water Source Will Determine the Possible Frequency of Testing * Obtained from California Strawberry Commission (1998) Quality Assurance Program Courtesy of FDA Courtesy University of Florida Keep records from the municipality/district water system (monthly, quarterly or annual report) Municipal/District water system Beginning, middle and week before harvest Uncovered well, open canal, water reservoir, collection pond One annual test at the beginning of season Closed system, under the ground or covered tank Possible Water Testing Frequency* Source

Sampling criteria can differ greatly <126 MPN for 5 samples <235 single NA NA CLGMA 50%<100 50%<100 50%<1000 Buyer 2 <10 <10 <100 Buyer 1 E. coli (CFU/100mL) Thermotolerant coliforms Cfu/100 mL) Total coliforms (cfu/100 mL)

Frost protection Water should meet pre-harvest criteria 126 E. coli per 100 mL If it is over this limit Do not use water until problem corrected Examine water source After actions taken retest water at sampling point Test water for 5 days sample the crop If crops positive do not use Photo by Donnie Fulks, Belvedere Plantation, Fredricksburg, VA

Water should meet pre-harvest criteria

126 E. coli per 100 mL

If it is over this limit

Do not use water until problem corrected

Examine water source

After actions taken retest water at sampling point

Test water for 5 days

sample the crop

If crops positive do not use

Drip irrigation More efficient irrigation method Less water lost to evaporation Less transfer of pathogens to plant

More efficient irrigation method

Less water lost to evaporation

Less transfer of pathogens to plant

Conclusions GAPs best way to prevent foodborne illness Water quality for irrigation should be 126 MPN/5 samples ( E.coli ) although this may vary Drip irrigation safer than overhead

GAPs best way to prevent foodborne illness

Water quality for irrigation should be 126 MPN/5 samples ( E.coli ) although this may vary

Drip irrigation safer than overhead

Acknowledgments Water Mark A. Ritenour, Ph.D. University of Florida, Indian River Research & Education Center, Fort Pierce Elizabeth A. Bihn and Robert B. Gravani National GAPs Program Cornell University

Resources http://www. ncagr . com/markets/gradnreg/foodsafety/index . htm Trevor Phister Phone: 919-513-1644 Email: tgphiste@ncsu.edu www.extensionfoodsafety.org