Food Protection Trends - July/August 2020 - 230

ready-to-eat products produced in a properly operated
inspected facility does not need additional washing unless
the need for washing is specifically stated on the label (31).
Some respondents mentioned using bleach or commercial
chlorine-based products for disinfection. This provides
some evidence of the general awareness of the need to
wash and disinfect raw vegetables before consumption, and
commercial chlorine-based products can be found easily
in most supermarkets in the country. Although there is a
recommendation for use of sodium hypochlorite (200-250
mg/l) for disinfection of fresh produce in processing sites
(6), several studies have shown that chlorine´s effectiveness
in reducing the microbial load on vegetables depends on
the level of organic load, and that there is a risk of toxic byproducts formation, highlighting the need of rinsing with
water after using chlorine to wash produce (18).
A large number of respondents reported adding culinary
vinegar to wash water for disinfection of leafy greens (Fig.
3), although the effectiveness of organic acids (e.g., acetic
acid) against foodborne pathogens depends on pH, type
and concentration of the acid, type of vegetable, strain of
microorganism, inoculum level and treatment time (1, 10, 17,
26, 29, 33, 35). High concentration of organic acids and long
contact times may also impact the organoleptic properties of
leafy vegetables. Some respondents mentioned using water
and dish soap for washing leafy greens, although this practice
should be avoided, as it may cause gastric disorders or other
symptoms (27).
Consumption surveys should always be interpreted with
care, as responses may be specific to a given geographic
region. A similar survey of consumer handling practices for
fresh produce carried out in Spain and Belgium, with 583
and 1,605 respondents, respectively, revealed differences

in the two countries. Vegetable consumption was higher in
Spain than in Belgium, whereas the opposite was found for
fruit consumption. Belgian consumers stored their fresh
produce in a refrigerator less frequently, and when they did
so, for shorter times compared with Spanish consumers. Few
consumers failed to wash head lettuce (1% in Belgium and
2% in Spain), but 50% of the Belgian respondents and 67% of
Spanish respondents did not wash prepackaged greens (25).
Our data add to this growing body of literature, all of which
may be useful in future risk assessment studies.
Our study contributes local data on the quantitative
consumption estimates and handling practices of leafy
greens by São Paulo residents, which are essential to support
the accuracy of exposure assessments in the construction
of risk assessment models. The data indicated an average
consumption of ~60 g per meal (~60 to 120 g per day)
and identified handling practices that would be useful in
predicting foodborne illnesses in leafy green quantitative
microbial risk assessments. The results also evidence the need
for education and handling tips for consumers regarding
best practices for leafy greens, focusing specifically on not
washing ready-to-eat produce and avoiding the use of soap
for leafy greens that need to be washed.
ACKNOWLEDGMENTS
The authors thank the São Paulo Research Foundation
(FAPESP, Brazil) through Grants #2013/07914-8 and
#2016/09601-5, the Coordination for the Improvement
of Higher Education Personnel (CAPES, Brazil) and
the National Council for Scientific and Technological
Development (PIBIC/CNPq, Brazil) for scholarships and
financial support.

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