The awareness of the importance of plants in the human diet has developed into detailed scientific study. The role of plants in medicine seems to have always been known and even today searches are being constantly made to find chemicals in plants that can be used to prevent or cure disease in modern medicine. A vast range of plant species have been eaten throughout the history of mankind. Presumably, initially human beings started using plants and their products from gathering them in the wild and eventually finding ways of cultivating them. This is the history of the development of agriculture. Even now people are still collecting plants for food from the wild in tandem with the development of breeding new cultivars of these crops and improved ways of cultivating them. Keller and Tukuitonga (2007) stated that ‘Low fruit and vegetable intake was identified as an important risk factor for chronic diseases in the WHO World Health Report 2002. Overall, it is estimated that up to 2.7 million lives could potentially be saved each year if fruit and vegetable consumption was sufficiently increased.’ The nutritional properties of vegetables and fruit have been known for centuries. In the 18th century a French pharmacist Antoine-Augustin Parmentier demonstrated, for several years by his own diet, that all the nutrients required to sustain a healthy life were found in potatoes (Block 2008). The quality of the plant material in terms of nutrition and the maintenance of that quality and reducing their physical losses from harvest to reaching the consumer have been the subject of a vast number of research projects. Changes that can occur may be due to infections by microorganisms or by the physiological processes that continue in vegetables and fruit since they are still living organisms with life processes that are severed from their sources of renewal and sustenance.

The technology involved in getting fresh produce from the field to the consumer is enormously complicated because many of the crops are highly perishable and variable. This variability militates against simple solutions. The fresh produce trade would prefer not to be involved with this variation and complexity. They would prefer to be able to look up their particular crop on a chart, which will say it should be harvested, packaged and stored in a certain way. Information in this form is readily available but will rarely give the best results in terms of preserving the quality of the crop. The objective of this book is the same as the two previous editions, which is to provide a range of postharvest options from which the produce technologist can select. Additionally it puts into context our current state of knowledge on postharvest science and technology and thus identifies areas where research is needed.

In order to provide a context for understanding the differences in research results and interpreting them some background information has been supplied on each fruit or vegetable. Also some taxonomy is included because of the difficulties in knowing exactly which crop the researchers have referred to. This may well help in determining the differences in results. The information in this book and the way that it is presented is therefore largely what is perceived to be required by the industry. Also there is increasing pressure for universities to provide graduates who are more relevant to the needs of industry, and most students of postharvest science and technology will eventually work in the industry or in some way be associated with it; so the book will also serve their needs. The parts on tropical root crops have relied heavily on two of the publications of Daisy Kay. From 1970 Daisy and I worked together at the Tropical Products Institute in London. TPI subsequently became the Tropical Development and Research Institute. The 1973 edition of her Root Crops: Crop and Product Digest was so well received that it was decided in the Institute to produce a second edition. Because Daisy had died and because of research and overseas consultancy work no one suitably qualified in the Institute had sufficient time to revise Daisy's work and so Graham Gooding was employed and with the co-operation of members of the Institute produced the excellent second edition in 1987. C.W. Wardlaw and his associates working in Trinidad at what eventually became the University of the West Indies is also a major source of information. Wardlaw was the Head of the Botany Department at Manchester University in 1960 and 1961 when I worked there as a lowly gardener in their Botanic Gardens. I subsequently was responsible for sorting out Wardlaw's notes and data and those of his predecessor S.C. Harland in Trinidad when the library at the University was relocated in 1969 while I was working there as a Research Fellow. Another major source is the work of Dr J.M. Lutz and Dr R.E. Hardenburg published in the United States Department of Agriculture Bulletin 66, which I was pleased to see has been revised and is constantly updated on the Internet by some of the most experienced postharvest technologists.

The work of this book is based on a selective review of the literature and my experiences since I was first formally involved in postharvest technology in 1967. Since that time postharvest technology has taken me all over the world doing short consultancies and long-term assignments, of up to 3 years, meeting particular challenges in research, training and development of the fruit and vegetable industry. Although much of my time has been spent as an academic and government or United Nations adviser, I have always worked closely with the horticultural industry. The information in this book and the way that it is presented is therefore largely in a form that I perceive to be required by the industry.

In this third edition I have brought the information up-to-date and widened its scope by including some fruit and vegetables that were not included in the first two editions. Comments have been made on the lack of information and discussion on the benefits of consumption of fruit and vegetables and levels of various nutrients they may contain and how these may change postharvest. So some nutritional data has been included and I am indebted to the USDA nutrient database for much of this information. Also I have included more details on taxonomy since it has been pointed out that there is often confusion as to which crop is being referred to. I have also included a little on the origin and history of the crops for which I have relied to a considerable degree on the excellent publications of Julia Morton and J.W. Purseglove.