Food Safety Risk Associated with Foods of Plant Origin

Consumers include foods of plant origin in their diet because they want to eat healthy. However, what many consumers do not realize is that consumption of these foods may pose a food safety risk. Foods contaminated with unacceptable levels of pathogenic micro-organisms, chemicals, or physical hazards can result in severe health and economic effects for consumers and society.

Foods of plant origin are those derived from plants which include:  

• produce (fruits and vegetables)
• sprouts
• culinary herbs
• nuts
• edible fungi
• maple and honey products
• grain products   

Factors Affecting Food Safety

  
Environment: Foods of plant origin are typically grown in fields exposed to organisms that are present naturally in the environment (ex: from soil, irrigation water, wildlife, etc.). Good agricultural practices (GAPs) help reduce the risks associated with these products but cannot guarantee a product free from pathogenic micro-organisms.


Post harvesting: Improper post harvest handling may contribute further contamination. Inadequate product storage conditions may also allow pathogenic micro-organisms that are present to multiply.


Processing: There is an increased demand for fresh cut produce including fruit trays, bagged salads and cut vegetables. Processing (peeling or cutting) fruits and vegetables increases the risk of contamination by breaking the natural outer barrier of the fruit and releasing juices which provides nutrients for pathogenic micro-organisms to grow, if present. These processes also involve product handling by personnel and/or equipment that if not hygienic can be a source of contamination. 

 
Inappropriate storage: Sales and consumption of ready-to-eat grain products has also increased. These grains rarely have a treatment to reduce the microbial load and may be a concern if stored or used under conditions that promote the growth of pathogenic micro-organisms (ex: mould producing mycotoxins).
 
The safety of food products must be ensured by using a preventative approach, including the implementation of good agriculture and manufacturing practices (GAP, GMP) and hazard analysis critical control point (HACCP). 


Overview of Food Borne Pathogens and Trends in Food

 
In 2011, the Centers for Disease Control (CDC) estimated that there are 31 pathogens known to cause food-borne illness that are responsible for approximately 9.4 million illnesses, 56 thousand hospitalizations and 1,400 deaths each year in the United States. The pathogen that is most commonly associated with hospitalization and death is salmonella.  
 

The Public Health Agency of Canada estimates that each year, roughly one-in-eight Canadians (or four million people) get sick due to food-borne illnesses.
 
The CDC monitored trends in food-borne illness over a period of 15 years. Over that time the incidence of infections by six food-borne pathogens (campylobacter, Listeria monocytogenes, E.coli  O157:H7, shigella and yersinia) declined by an average of 23 per cent. However, the incidence of salmonella infections increased. Salmonella is difficult to control because it can contaminate a wide range of foods and has many different animal and environmental reservoirs. 
  
In general, most people assume that the foods that pose the greatest risk to consumers are raw meat products. However, the CDC attributes a downward trend in most pathogens to cleaner slaughter methods, microbial testing and better inspection practices in the meat industry, as well as increased awareness of the food service industry and consumers, of the risk of undercooked ground meat.  
 

Food Recall Trends

 
The trends in Canadian food recalls for 2013 indicate that a greater number of foods of plant origin are recalled due to microbiological concerns than other commodities, implying that there is an increased food safety risk associated with their consumption.  
 
# of recalls caused by:
2013
Raw – meat
RTE – fresh (or minimally processed) foods of plant origin
RTE-meat
Other – RTE processed products ex: baked goods, cheese, etc.
Total
Listeria monocytogenes
0
1
4
6
11
salmonella
0
18
1
0
19
E.coli  (pathogenic)
5
0
0
1
6
Clostridium botulinum
0
1
4*
0
5
Total
5
20
8
7
41

 *All products recalled due to Clostridium botulinum were smoked or cured meat and fish products.

 

Food-Borne Illness Outbreaks


Since most foods of plant origin are consumed fresh, without further cooking, the risk of contaminated foods of plant origin causing food-borne illness is higher. Produce may be washed using water or disinfectants at a safe concentration, however, pathogens inside the product will not be affected. Pathogens can enter produce by capillary action through bruises, blossom or stem scars. One study indicated if salmonella is applied to the pollen tube of a (tomato) flower, it can be isolated from the fruit when mature.

 Examples of food of plant origin food-borne illness outbreaks:
Year
Company
Country
Product
Organism
Illnesses/Deaths
Cause (if known)
2014
Not identified
Canada and United States
sprouted chia seeds
Salmonella (4 different strains)
63 illnesses in Canada
31 illnesses in the US
5 hospitalizations
0 deaths
unknown
2013
Daniel Cardenas Izabal and Miracle Greenhouse
United States
cucumbers
Salmonella Saintpaul
84 illnesses
17 hospitalizations
0 deaths
unknown
2012
Daniella brand mangoes – distributed by Splendid Products
Canada and United States (product imported from Mexico)
mangoes
Salmonella
Braenderup
178 illnesses in the US
25 hospitalizations
0 deaths
unknown
2011
Jensen Farms
United States - Colorado
cantaloupe
Listeria monocytogenes (listeriosis)
146 illnesses
30 deaths
1 miscarriage
 
poor post harvest handling practices
2011
Agromod Produce Inc.
United States (imported from Mexico)
papaya
Salmonella Agona
106 illnesses
10 hospitalizations
0 deaths
unknown
2011
an unnamed German organic farm
Europe (including Germany and France)
fenugreek sprouts
E.coli (STEC O104:H4)
~4000 illnesses
>50 deaths
contaminated seeds

20082009
Peanut Corporation of America
United States
peanuts
Salmonella
Typhimurium
714 illnesses
24% hospitalized
9 deaths
pest infestation, leaky roof, unsanitary conditions

 

Preventative Recommendations


Traditionally, resources have focused on reducing food-borne illness caused by meat, but trends in food production and consumption indicate that food-borne illness is a significant and growing concern that should not be overlooked.

Since fresh produce is eaten without cooking, to avoid food-borne illness the focus needs to be on preventing contamination. To help identify potential risk in foods of plant origin producers, processors and those involved along the food chain need to evaluate their commodities, perform a risk assessment to identify potential hazards and establish control measures. The risk of contamination can be reduced by:

  • implementing on-farm food safety practices (ex: good agricultural practices)
    • ensure quality/safety of irrigation and post harvest cooling water
    • protection from fecal contamination
    • washing/sanitizing fresh produce (if applicable)
    • control storage conditions 
    • control food handlers (follow proper hygienic practices)
  • implementing food safety programs in facilities that cut and package fresh fruits and vegetables
    • sanitation of equipment
    • proper sanitary design of facility and equipment
    • control of food handlers (follow proper hygienic practices)