Handling and Preservation of Fruits and Vegetables by Combined Methods for Rural Areas


TECHNICAL MANUAL
FAO Agricultural Services Bulletin 149

by
Gustavo V. Barbosa-Cánovas
Juan J. Fernández-Molina
Stella M. Alzamora
Maria S. Tapia
Aurelio López-Malo
Jorge Welti Chanes

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Rome, 2003

ISBN 92-5-104861-4

Table of Contents



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FAO 2003


Table of Contents


FOREWORD

ACKNOWLEDGEMENTS

INTRODUCTION

CHAPTER 1. FRUITS AND VEGETABLES: AN OVERVIEW ON SOCIO-ECONOMICAL AND TECHNICAL ISSUES

1.1 Trade and global trends: Fruits and vegetables
1.2 Traditional consumption
1.3 Economic and social impact
1.4 Commercial constraints
1.5 Post-harvest losses and resource under-utilization in developing countries

1.5.1 Food losses after harvesting
1.5.2 Food losses due to social and economic reasons

1.6 Pre-processing to add value
1.7 Pre-processing to avoid losses
1.8 Alternative processing methods for fruits and vegetables in rural areas

1.8.1 Scalding or blanching in hot water
1.8.2 Cooling in trays
1.8.3 Sulphiting
1.8.4 Sun drying and osmotic dehydration
1.8.5 Fermentation
1.8.6 Storage
1.8.7 Sample calculation for adjusting fruit soluble solids and acid contents

CHAPTER 2. BASIC HARVEST AND POST-HARVEST HANDLING CONSIDERATIONS FOR FRESH FRUITS AND VEGETABLES

2.1 Harvest handling

2.1.1 Maturity index for fruits and vegetables
2.1.2 Harvesting containers
2.1.3 Tools for harvesting
2.1.4 Packing in the field and transport to packinghouse

2.2 Post-harvest handling

2.2.1 Curing of roots, tubers, and bulb crops
2.2.2 Operations prior to packaging
2.2.3 Packaging
2.2.4 Cooling methods and temperatures
2.2.5 Storage
2.2.6 Pest control and decay

CHAPTER 3. GENERAL CONSIDERATIONS FOR PRESERVATION OF FRUITS AND VEGETABLES

3.1 Water Activity (aw) concept and its role in food preservation

3.1.1 aw concept
3.1.2 Microorganisms vs. aw value
3.1.3 Enzymatic and chemical changes related to aw values
3.1.4 Recommended equipment for measuring aw

3.2 Intermediate Moisture Foods (IMF) concept

3.2.1 Fruits preserved under IMF concept
3.2.2 Advantages and disadvantages of IMF preservation

3.3 Combined methods for preservation of fruits and vegetables: a preservation concept

3.3.1 Why combined methods?
3.3.2 General description of combined methods for fruits and vegetables
3.3.3 Recommended substances to reduce aw in fruits
3.3.4 Recommended substances to reduce pH
3.3.5 Recommended chemicals to prevent browning
3.3.6 Recommended additives to inhibit microorganisms
3.3.7 Recommended thermal treatment for food preservation

CHAPTER 4. EXTENSION OF THE INTERMEDIATE MOISTURE CONCEPT TO HIGH MOISTURE PRODUCTS

4.1 Preliminary operations
4.2 Desired aw and syrup formulation

4.2.1 Calculus required
4.2.2 Water content vs. aw relationship

4.3 Example of application
4.4 Packaging methods for minimally processed products

4.4.1 Packaging with small units
4.4.2 Transport the package
4.4.3 Loading packaging units
4.4.4 Vacuum and modified atmosphere packaging

4.5 Transport, storage, and use of fruits preserved by combined methods

4.5.1 Open vs. refrigerated vehicles
4.5.2 Unloading
4.5.3 Storage temperature vs. shelf life
4.5.4 Repackaging considerations
4.5.5 Syrup reconstitution and utilization
4.5.6 Optimal utilization of the final product

4.6 Quality control

4.6.1 Recommended microbiological tests
4.6.2 Nutritional changes
4.6.3 Changes in sensory attributes and acceptability

CHAPTER 5. PROCEDURE FOR VEGETABLES PRESERVED BY COMBINED METHODS

5.1 Preliminary operations
5.2 Combined optional treatments

5.2.1 Irradiation
5.2.2 Refrigeration
5.2.3 Modified atmospheres
5.2.4 Pickling
5.2.5 Fermentation

5.3 Packaging methods

5.3.1 Plastic containers and bags
5.3.2 Vacuum packaging
5.3.3 Modified atmosphere packaging

5.4 Transport, storage, and use of vegetables preserved by combined methods

5.4.1 Open vs. refrigerated vehicles
5.4.2 Unloading
5.4.3 Storage temperature vs. shelf life
5.4.4 Repackaging considerations
5.4.5 Optimal utilization of the final product

5.5 Quality control

5.5.1 Recommended microbial tests
5.5.2 Nutritional changes
5.5.3 Changes in sensory attributes and acceptability

REFERENCES

GLOSSARY

FAO TECHNICAL PAPERS

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