GENEVA, Switzerland -- Consumption of fresh produce has increased in recent years, prompted by healthy eating campaigns. However, compared to previous years, fruit and vegetables are now being identified more frequently as the source of a growing number of outbreaks associated with zoonotic pathogens.
Between 2003 and 2008, the food vehicles identified in 1,565 outbreaks reported to the Centers for Disease Control and Prevention (CDC) are a broad spectrum of animal- and plant-derived foods. It is curious that while many of the pathogens have animal reservoirs, many new food vehicles are plant derived. This includes plant-derived processed foods.
Consumer demand for greater choice, variety and year-round availability of fruit and vegetables, as well the vogue for convenient ‘ready to serve’ products has driven the globalization of supply chains and increased pressure on the food industry and compromised safety.
Proximity to Pathogens Increases Risk of Food Contamination
Zoonotic pathogens are not commonly present in fruit and vegetables in nature. Human intervention and commercial food production practices have brought the two into close proximity.
Pathogens may be naturally present in soil, or may become incorporated in the soil from organic wastes added as fertilizer, or by accidental contamination. For example, water supplies used to wash and irrigate crops can be contaminated with fecal material (and its pathogens) by run-off from nearby fields and livestock farming.
Pathogens Survival On and In Plants
Pathogens in water used for spraying can remain on fruits and vegetables and survive on these new carriers. Studies have shown that some enteropathogens are quite adept at surviving on the leaf surface (phylloplane). Effective washing and exposure to UV radiation can typically deal with surface contamination.
Pathogens do not always die on leaving the host animal, but may find a new carrier in the form of plants. Plants sprayed with contaminated water can absorb pathogens through any wounds to the flesh. This is a particular issue with popular consumer items such as pre-prepared lettuce and salads. Internalization of pathogens into plants may also be possible through stomata and hydathodes (permanently open water pores). Furthermore, contaminated irrigation water can be taken up by a plant’s root system and any pathogens can be stored within its flesh.
Preventing Food Contamination
There is little that consumers can do to protect themselves from fruit and vegetable contamination, as these products are often not cooked. Washing them has little effect on any contamination.
In theory, existing regulations and the food industry requirement that all processors and manufacturers implement hazard analysis and critical control point (HACCP) strategies, should prevent environmental contamination reaching the consumer.
All HACCP plans should be reviewed regularly. They must deal not only with questioning whether the water at a facility is safe to use, but also if that water source is trusted and protected against potential contamination. Post-harvest contamination is also known to result from poor food handling processes and poor worker hygiene. Processors need to ensure that HACCP plans are robust, documented and implemented.
Food Testing on End Products
The food industry has, out of necessity, invested heavily in microbiological testing and surveillance programs. Fruit and vegetable products can undergo microbiological testing at any stage of the supply chain but are most commonly checked as the end product. This enables processors to identify any pathogen contamination before goods reach the point of sale.
An integrated testing program (http://www.sgs.com/en/Consumer-Goods-Retail/Food/Primary-...) can verify the microbial quality of products and in the event of contamination being identified, prevent them reaching the consumer.
Food Safety - Next Steps
Global supply chains mean that contamination issues in one part of the world can quickly spread. Existing food safety systems have focused on post-harvest safety, hygiene, handling and testing. Improving food safety going forward will likely rely on increased awareness of public health issues and enforcement of regulations in new and developing markets. This should be complemented by increased focus on identifying contaminations (http://www.sgs.com/en/Consumer-Goods-Retail/Food/Primary-...) earlier, preventative in-field solutions and introducing stricter practices more in line with livestock farming.
For further information, please contact the SGS experts.
Contact details:
SGS Consumer Testing Services
Ron Wacker, PhD
Global Food Testing Business Development Manager
SGS Germany
t: +49 6039 4696
Email: cts.media@sgs.com
Website: www.foodsafety.sgs.com
SGS is the world’s leading inspection, verification, testing and certification company. SGS is recognized as the global benchmark for quality and integrity. With more than 75 000 employees, SGS operates a network of over 1 500 offices and laboratories around the world.
Media Contact
Ron Wacker
+49 6039 4696
cts.media@sgs.com
