Yahia Postharvest Biology and Technology of Tropical and Subtropical Fruits

Fundamental Issues
1. Auflage 2011
ISBN: 978-0-85709-362-2
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 534 Seiten

Reihe: Woodhead Publishing Series in Food Science, Technology and Nutrition

Tropical and subtropical fruits are popular products, but are often highly perishable and need to be transported long distances for sale. The four volumes of Postharvest biology and technology of tropical fruits review essential aspects of postharvest biology, postharvest technologies, handling and processing technologies for both well-known and lesser-known fruits. Volume 1 contains chapters on general topics and issues, while Volumes 2, 3 and 4 contain chapters focused on individual fruits, organised alphabetically.Volume 1 provides an overview of key factors associated with the postharvest quality of tropical and subtropical fruits. Two introductory chapters cover the economic importance of these crops and their nutritional benefits. Chapters reviewing the postharvest biology of tropical and subtropical fruits and the impact of preharvest conditions, harvest circumstances and postharvest technologies on quality follow. Further authors review microbiological safety, the control of decay and quarantine pests and the role of biotechnology in the improvement of produce of this type. Two chapters on the processing of tropical and subtropical fruit complete the volume.With its distinguished editor and international team of contributors, Volume 1 of Postharvest biology and technology of tropical and subtropical fruits, along with the other volumes in the collection, will be an essential reference both for professionals involved in the postharvest handling and processing of tropical and subtropical fruits and for academics and researchers working in the area. - Along with the other volumes in the collection, Volume 1 is an essential reference for professionals involved in the postharvest handling and processing of tropical and subtropical fruits and for academics and researchers working in the area - Focuses on fundamental issues of fruit physiology, quality, safety and handling relevant to all those in the tropical and subtropical fruits supply chain - Chapters include nutritional and health benefits, preharvest factors, food safety, and biotechnology and molecular biology

Autoren/Hrsg.

Yahia, Elhadi M.

Leseproben

Preface
Elhadi M. Yahia Introduction to tropical and subtropical fruits
Tropical and subtropical fruits include a large number of crops such as acerola, aonla, avocado, bael, banana, black sapote, breadfruit, breadnut, carambola, cherimoya, chili plum, citrus fruit, cocona, coconut, date, durian, feijoa, fig, golden apple, grape, guava, jaboticaba, jackfruit, kiwifruit, longan, loquat, litchi, macadamia, mamey sapote, mango, mangosteen, nance, noni, olive, papaya, passion fruit, pecan, persimmon, pineapple, pistachio, pitahaya, pitanga, pomegranate, rambutan, salak, sapodilla, soursop, star apple, tamarillo, tamarind, wax apple, among many others (see volumes 2, 3 and 4 of this collection). They are important commodities with multiple uses, and their contribution to human nutrition and health and lives is very significant. Tropical and subtropical fruit plants come from a wide range of botanical families, are of different types, including vines (e.g. passion fruit), herbaceous crops (e.g. bananas) and woody plants (e.g. oranges), and produce various kinds of fruit such as berries (e.g. avocados), drupes (e.g. mangoes), nutlets (e.g. litchis) and compound fruits (e.g. pineapples). It is not straightforward to make a distinction between tropical and subtropical fruits, and, indeed, several can be cultivated both in the tropics and subtropics. Citrus, for example, is of tropical origin, yet achieves better quality when grown in the subtropics, or at higher elevations in the tropics. The geographical boundaries of the tropics may not, in fact, be the best indication of whether a fruit is tropical or subtropical, as some areas within the tropics have a climate that is not typically considered tropical, due to factors such as altitude. In general, tropical areas are those which remain constantly warm. In other words, they are areas in which the warmest month is only a few degrees hotter than the coldest, temperature differences between day and night are greater than those between summer and winter and there is little variation in day length. Subtropical regions generally have a greater difference in temperature between summer and winter and are less humid. Though there are tropical and subtropical fruit native to almost all continents, the majority of the most widely traded species originate from the American continent (e.g. papayas, guavas) or Asia (e.g. most citrus fruits, mangoes and bananas), some exceptions being dates from Africa and coconuts from Oceania. Tropical and subtropical fruits have long been part of the diet in certain areas. While the general public may just now be discovering many tropical fruits, these delicacies have served as staples for some cultures for generations. Mango has been cultivated and consumed in India for more than 4000 years, the Chinese have harvested litchis for thousands of years, carambolas (starfruit) have been popular in Malaysia for centuries, papaya was enjoyed throughout Latin America long before Columbus’s arrival, and dates have been the staple food of the Middle East and North Africa for thousands of years. Tropical and subtropical fruit are thought to have spread very early from their respective areas of origin. For example, the conquest of parts of the Iberian peninsula by Moorish Muslim armies from North Africa brought oranges to southern Europe, and the Europeans brought crops from the New World back to the Old World. In general, the establishment of trade routes facilitated the spread of crops, especially those whose fruit and planting material could survive long voyages. Trade in tropical and subtropical fruits
The major traded tropical and subtropical fruits include citrus fruits, banana, mango, pineapple and papaya. Some other tropical and subtropical fruits, such as durian and mangosteen, are not so extensively cultivated or traded, but are still important economically in their own regional markets. There are also a significant number of tropical and subtropical fruits which are not cultivated commercially. According to 2010 FAO statistics, world production of certain fruit amounts to the following: banana – almost 60 million tonnes (mmt), mango – almost 25 mmt, papaya – more than 8 mmt, pineapple – more than 13 mmt and plantain – more than 30 mmt. About 98% of tropical fruits and significant quantities of subtropical fruits are produced in developing countries. More than 50% of tropical and subtropical fruits are consumed fresh, and the rest is consumed in many different processed forms. There has been a major drive to promote several minor fruits (including many tropical and subtropical fruits) in international trade, but in general, it can be postulated that a significant gap still exists between world per capita consumption and estimated consumption saturation. Immigrant communities in several countries (including North America and European countries) who have used minor fruits in their diet for generations, have played a role in the establishment of new markets in their adopted countries of residence. In addition, tourists and travelers from many Western countries have been exposed to many of these fruits in the tropics and subtropics and have either started to demand that they are stocked in the shops and marketplaces they usually frequent, or have begun to acquire them from shops and marketplaces that cater primarily for immigrants. In addition, there are areas in North America (around the southern tip of Florida, Hawaii, Puerto Rico) and in Europe (such as in the Canary Islands) which have suitable climates for tropical fruits, and fruits grown in those regions have also found their way to markets and consumers elsewhere in the United States and Europe, therefore increasing the promotion of these minor fruits. The increasing interest in and marketing prospects for tropical and subtropical fruits worldwide have made the science underpinning postharvest technologies for these fruits a priority research and development area in several countries, including many developing countries. There is increasing demand for tropical and subtropical fruit handling information from shippers, importers and trade organizations. However, making handling information available is often of limited importance to whole regions (this applies especially to information on some very minor and exotic fruits). This refl ects the characteristics of several tropical and some subtropical fruit industries: they are comparatively small, dispersed and fragmented and production is highly seasonal. Production also mostly takes place in developing countries, where adequate distribution systems are yet to be established. It is in the economic and national interest of food/fruit exporting countries to possess and maintain an international commercial reputation as a reliable supplier of products of acceptable sensory and safety quality, and therefore the establishment of adequate postharvest handling systems for these fruits is essential. Postharvest handling systems for tropical and subtropical fruits
Most tropical fruits and several subtropical fruits are highly perishable and can only be maintained for short periods of time (from a few days to a very few weeks), but some fruits can be maintained for extended period of time (such as oranges, some cultivars of table grapes, nuts and dried fruits). The three major postharvest problems that affect tropical and subtropical fruits (especially tropicals) are chilling injury, decay and insect damage. Chilling injury (CI) is a common problem in most tropical and several subtropical fruits. Most temperate fruits can be stored for the longest period of time at around 0°C (just above the freezing point), and are injured only if they freeze. However, many tropical and subtropical fruits are injured by low, nonfreezing temperatures in the range 0°–13°C. CI results in surface pitting, browning of the peel and flesh, and faster postharvest decay development. Thus, postharvest temperature control is even more critical for tropical and subtropical fruits than for temperate fruits. The high perishability of these fruits (especially tropical fruits) is due not only to the higher storage temperature requirements, but also to their general nature: most tropical fruits are climacteric and produce high quantities of ethylene, but some, such as citrus, are ‘non-climacteric’. Citrus fruit ripen slowly, without going through a burst of respiration, softening, and color change right at the end of development, and can be stored on the tree for several weeks, widening the window in which the crop can be marketed and allowing for greater marketing flexibility. Almost all tropical fruits and most subtropical fruits are produced in developing countries and postharvest handling systems in these areas are, in most cases, not adequately developed (see Plate Ia in the color section between p 238 and p 239). Therefore rates of deterioration and losses are commonly high. Common inadequate handling practices causing significant qualitative and quantitative losses include a lack of adequate ripening indices and harvesting methods, a non-existent or inadequate cold chain and inadequate storage and marketing practices (Plate Ia). However, there have recently been improvements in the postharvest handling in particular of fruit for export, and also of locally marketed crops. Plate Ib shows fruits of excellent quality in a local supermarket in a developing country. Fruit intended for export is commonly handled better in developing countries, but improvements have also been seen in postharvest handling of locally consumed...