Microbiological hazards in fresh leafy vegetables and herbs

163 Pages·2009·1.06 MB·English

MICROBIOLOGICAL RISK ASSESSMENT SERIES
14

Microbiological hazards in fresh leafy vegetables and
herbs
Meeting report
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For further information on the joint FAO/WHO activities on microbiological risk assessment,
please contact:
Nutrition and Consumer Protection Division
Food and Agriculture Organization of the United Nations
Viale delle Terme di Caracalla
00153 Rome, Italy
Fax: [phone]
E-mail: [email protected]
Web site: http://www.fao.org/ag/agn
or
Department of Food Safety, Zoonoses and Foodborne Disease
World Health Organization
20, Avenue Appia
CH-1211 Geneva 27
Switzerland
Fax: [phone]
E-mail: [email protected]
Web site: http://www.who.int/foodsafety

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imply the expression of any opinion whatsoever on the part of the Food and Agriculture
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distributed without warranty of any kind, either expressed or implied. The responsibility for the
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liable for damages arising from its use.

Recommended citation: FAO/WHO [Food and Agriculture Organization of the United
Nations/World Health Organization]. 2008. Microbiological hazards in fresh leafy vegetables and
herbs: Meeting Report. Microbiological Risk Assessment Series No. 14. Rome. 151pp.

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Health Organization, 20 Avenue Appia, CH-1211 Geneva 27, Switzerland, or by facsimile to +41
22 7914806, or by e-mail to [email protected].

© FAO and WHO 2008
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CONTENTS
Acknowledgements ix
Contributors (Meeting Participants) x
Declarations of interest xi
Foreword xiii
Abbreviations xv

Executive summary xvii
Pre-harvest of leafy vegetables and herbs xvii
Post-harvest of leafy vegetables and herbs xix

1. Introduction 1
1.1 Background 1
1.2 Objectives 3
2. Fresh and fresh-cut leafy vegetables and herbs 5
2.1 Scope 5
2.2 International production and trade 5
2.3 Foodborne illness 7
2.3.1 Microbial hazards 7
2.3.2 Epidemiology 7
2.3.3 Microorganisms and fresh leafy vegetables and herbs relevant to food safety 8
2.4 Overview of production systems for leafy vegetables and herbs 9
3. Production environment of leafy vegetables and herbs 11
3.1 Wildlife, livestock, human activity 11
3.1.1 Problem scope 11
3.1.2 Potential impact 11
3.1.3 Available data 11
3.1.4 Uncertainty and data gaps 14
3.1.5 Mitigation recommendations 14
3.2 Topography and climate 16
3.2.1 Problem scope 16
3.2.2 Potential impact 16
3.2.3 Available data 17
3.2.4 Uncertainty and data gaps 18
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3.2.5 Mitigation recommendations 18
3.3 Flooding 18
3.3.1 Problem scope 18
3.3.2 Potential impact 18
3.3.3 Available data 18
3.3.4 Uncertainty and data gaps 19
3.3.5 Mitigation recommendations 19
3.4 Seeds and crop selection 19
3.4.1 Problem scope 19
3.4.2 Potential impact 19
3.4.3 Available data 20
3.4.4 Uncertainty and data gaps 20
3.4.5 Mitigation recommendations 20
3.5 Prior land use and assessment 20
3.5.1 Problem scope 20
3.5.2 Potential impact 20
3.5.3 Available data 21
3.5.4 Uncertainty and data gaps 21
3.5.5 Mitigation recommendations 21
4. Soil amendments and fertilizers 23
4.1 Problem scope 23
4.2 Potential impact 23
4.3 Available data 23
4.3.1 Survival in manure 23
4.3.2 Survival in manure-amended soil 23
4.3.3 Survival of viruses 24
4.3.4 Human biosolids 24
4.3.5 Plant biowaste 26
4.3.6 Pathogen association with leafy vegetables grown in manure-amended soil 26
4.4 Uncertainty and data gaps 26
4.5 Mitigation recommendations 27
5. Water 29
5.1 Problem scope 29
5.2 Potential impact 29
5.3 Available data 29
5.3.1 Human pathogens in water and their transfer to leafy vegetables 30
5.3.2 Pathogens in agricultural waters from various sources 30
5.3.3 Pathogens in groundwater 30
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5.3.4 Pathogens in surface waters 31
5.3.5 Pathogens in reclaimed wastewater 31
5.3.6 Fate of human pathogens: effect of timing of irrigation 31
5.3.7 Influence of irrigation systems 32
5.3.8 Contamination of farm chemicals and cleaning water 32
5.4 Uncertainty and data gaps 33
5.5 Mitigation strategies 33
6. Harvest, field packing and packinghouses 35
6.1 Problem scope 35
6.2 Potential impact 35
6.3 Harvest 35
6.3.1 Available data 35
6.3.2 Uncertainty and data gaps 38
6.3.3 Mitigation recommendations 38
6.4 Field packing and packinghouses 38
6.4.1 Available data 38
6.4.2 Uncertainty and data gaps 40
6.4.3 Mitigation recommendations 40
7. Processing 41
7.1 Problem scope 41
7.2 Potential impact 41
7.3 Primary preparation 41
7.3.1 Mitigation recommendations 42
7.4 Further processing 42
7.4.1 Size reduction 42
7.4.2 Washing and sanitizing 43
7.4.3 Microbial attachment and internalization 45
7.4.4 Drying 46
7.5 Packaging 47
7.5.1 Data gaps 48
7.5.2 Mitigation recommendations 48
7.6 Chilled Storage 48
8. Marketing and the cold chain 49
8.1 Problem scope 49
8.2 Potential impact 49
8.3 Available data 49
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8.3.1 Pathogen contamination 50
8.3.2 Pathogen growth and survival during distribution 50
8.3.3 Relationship between shelf life and safety in leafy vegetables 51
8.3.4 Implications of failure in the cold chain 51
8.3.5 Effect of marketing practices 52
8.4 Uncertainties and data gaps 52
8.5 Mitigation recommendations 53
9. Education and training 55
9.1 Problem scope 55
9.2 Potential issues 55
9.3 Key considerations in education and training 55
9.3.1 Priority target groups for training and education 56
9.3.2 Topics for inclusion in training programmes 56
9.4 Consumer education 57
9.4.1 Important Considerations 58
10. Data gaps 61
10.1 Pre-harvest 61
10.2 Harvest 62
10.3 Packing 62
10.4 Processing 62
10.5 Marketing and the cold chain 63
10.6 The final consumer 64
11. Response to Codex, and Recommendations 65
11.1 Response to Codex 65
11.1.1 Environmental Hygiene 65
11.1.2 Soil amendments and fertilizers 70
11.1.3 Water 71
11.1.4 Personnel health, personnel hygiene and sanitary facilities 75
11.1.5 Packing and post-harvest process operations 76
11.1.6 Maintenance of the cold chain 78
11.2 Conclusions and recommendations 79
12. Bibliography 83

ANNEX 1 101
ANNEX 2 103
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ANNEX 3 123
ANNEX 4 135

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Acknowledgements

The Food and Agriculture Organization of the United Nations (FAO) and the World Health
Organization (WHO) would like to express their appreciation to all those who contributed to the
preparation of this report through the provision of their time and expertise, data and other
relevant information. In particular, the work of Patricia Desmarchelier in reviewing and
summarizing the information received in response to the call for data, and for acting as
rapporteur for the meeting and assisting in the preparation of this report is acknowledged. In
addition, appreciation is extended to her employers, Food Science Australia, for releasing her
from her daily activities to undertake this work. This collaboration was undertaken under the
FAO Programme of Cooperation with Academic and Research Institutions. The assistance of
Yoshimasa Sasaki in reviewing and summarizing some of the available information and the
support provided by the Ministry of Agriculture in Japan that facilitated this is also
acknowledged.
Appreciation is also extended to all those who responded to the call for data that was issued
by FAO and WHO and by the Codex Secretariat by means of a Circular Letter to all Codex
Members. In particular, FAO and WHO appreciate the information brought to their attention
that is not readily available in the peer reviewed literature and official documentation.
The preparatory work and expert meeting convened to prepare this report were coordinated
by the Secretariat of the Joint FAO/WHO Expert Meetings on Microbiological Risk Assessment
(JEMRA). This included Sarah Cahill and Maria de Lourdes Costarrica in FAO, and Peter
Karim BenEmbarek in WHO. The extensive support provided by the Office of the WHO
Representative to Thailand and in particular Chawalit Tantinimitkul and Suwanna Sangsuwan in
providing logistical support to this meeting, and the assistance of Peter Hoejskov and Biplap
Nandi in the FAO Regional Office for Asia and the Pacific, is also acknowledged. Publication
of the report was coordinated by Sarah Cahill and Mary Friel. Final editing for language and
style and preparation for publication was by Thorgeir Lawrence. The work was supported and
funded by contributions from the United States Food and Drug Administration and the Ministry
of Health, Labour and Welfare, Japan.
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Contributors (Meeting Participants)

Experts
Philip AMOAH International Water Management Institute (IWMI) Africa Office, Accra, Ghana.
Robert BUCHANAN Center for Food Safety and Applied Nutrition (CFSAN), US Food and Drug
Administration, United States of America.
Bussara Quality and Product Standards Inspection Group, Department of Agriculture and
CHANKAEWMANEE Cooperatives, Thailand.
Pascal DELAQUIS Agriculture and Agri-Food Canada, Pacific Agri-Food Research Centre, Canada.
Silvia ESTRADA-FLORES Food Chain Intelligence, Australia.
Franz EELCO RIKILT – Institute of Food Safety, Cluster Databases, Risk assessment & Supply
Chain Management, the Netherlands
Victor GARCIA MORENO Col. del Carmen Coyoacán, México.
Karin GOODBURN Chilled Food Associates, United Kingdom.
Joaquín VICENTE BAÑOS Instituto de Investigación en Recursos Cinegéticos, Spain.
Shinichi KAWAMOTO Food Safety Division, National Food Research Institute, Japan.
Jeffrey LEJEUNE Food Animal Health Research Program, Ohio Agricultural Research and
Development Center, United States of America.
Yaguang LUO Produce Quality and Safety Laboratory, USDA ARS, United States of America.
Christophe NGUYEN THÉ French National Institute for Agricultural Research (INRA), France.
Nicola SILVANA AGROSELVITER, Facoltà di Agraria, University of Turin, Italy.
Linus OPARA College of Agricultural and Marine Sciences, Sultan Qaboos University, Oman.
Robert PREMIER Department of Primary Industries, Victoria, Australia.
Frances Ann WARNOCK Safe Food Connexions, Australia.

Resource persons
Amy GREEN Center for Food Safety and Applied Nutrition (CFSAN), US Food and Drug
Administration, United States of America.
Voranuch KITSUKCHIT National Bureau of Agricultural Commodity and Food Standards, Thailand.
Jeronimus MASKELIUNAS Joint FAO/WHO Food Standards Programme, Rome, Italy.
Pisan PONGSAPITCH National Bureau of Agricultural Commodity and Food Standards, Thailand.
Jiraratana THESASILPA Ministry of Public Health, Thailand.
Jongkolnee Ministry of Public Health, Thailand.
VITHAYARUNGRUANGSRI