Fresh-cut Mangoes for the Market
Mangoes could be an attractive addition to the growing market for fresh-cut produce, but browning and drying have prevented such marketing. Researchers at the USDA-ARS Horticultural Crops Quality Laboratory found that fresh-cut mangoes could be preserved by treating the slices with a combination of hexylresorcinol, isoascorbic acid and potassium sorbate (all food-safe compounds derived from natural products) and storing the slices in plastic containers to prevent drying.
Treating whole fruits with methyl jasmonate (an inexpensive product derived from plant essential oils) prevented the development of chilling injury during cold storage and hence markedly increased fruit quality after storage. The treatment worked on fruits at various stages of maturity and had no effect on ripening or softening processes or water loss.
For further information contact: Chien Y. Wang, USDA-ARS Horticultural Crops Laboratory, Beltsville, Maryland, USA. Tel: (301) 5046128 Email:

FAIR Project Assesses Mealiness in Apples

Participants in the European FAIR project (CT 95-302) developed non-destructive techniques for the measurement of mealiness in apples and studied the factors affecting mealiness and its effects on consumers.
Mealiness is described as the tendency of fruits to disintegrate, combined with a sensation of lack of juiciness and dryness in the mouth, as well as the absence of flavour. In December 1996, researchers from the Universidad Politécnica de Madrid (UPM), from Katholieke Universiteit Leuven (KU) and from the Institute of Food Research in the UK carried out trials to determine correlations between the assessment of mealiness by a panel and objective measurements (mechanical resonance and confined compression). The results allowed the development of techniques for determining crispness (the absence of which is correlated with mealiness), hardness and juiciness (also correlated with mealiness) without the need for taste panels.
A scale for determining mealiness was used by UPM, in collaboration with IRTA (Spain), for studying factors which could affect the incidence of mealiness in apples. The studies concluded that (i) large-size Top Red apples harvested late showed a high incidence of mealiness, and (ii) no effect of harvesting date on mealiness was observed in Golden Delicious apples, although fruit size and mealiness were linked. Similar studies carried out at KU and VCBT (Flemish Centre for Storage of Agricultural Products), combining harvesting dates, fruit size and the concentration of oxygen in the storage atmosphere, showed that, after 6 months' storage, apples stored in air showed a higher incidence of mealiness than those held in a low-oxygen atmosphere.
Surveys of producers, distributors and consumers indicated that all groups perceived mealiness as detrimental to fruit quality, although there was a segment of older consumers who preferred mealy fruits because they were softer and overmature. The quality characteristic rated highest was taste, followed by appearance and firmness.

Hawaiian Bananas Free from Fruit Flies

Research carried out by John W. Armstrong and colleagues at the US Pacific Basin Agricultural Research Center in Hilo, Hawaii has allowed the USDA's Animal and Plant Health Inspection Service to approve new, workable regulations for shipping bananas grown in Hawaii to the US mainland. Since the ban on ethylene dibromide was imposed in 1984, bananas have not been shipped to the mainland due to the threat of fruit fly infestation. Mediterranean (Ceratitis capitata) and oriental fruit flies (Bactrocera dorsalis) are established in Hawaii and pose a threat to mainland agriculture where they can attack more than 200 fruits and vegetables.
Using laboratory-reared fruit flies, thousands of bananas from nearly 2 dozen plantations throughout the State were tested. The research, carried out in the laboratory and outdoors, demonstrated that bananas won't harbour these pests if shipped full-size, green-skinned and without cuts or punctures. Shipments to other markets such as Japan are now on the horizon.
For further information contact:
John Armstrong, USDA-ARS,  US Pacific Basin Agricultural Research Center, Stainback Highway,
PO Box 4459, Hilo, HI 96720, USA.Tel: (808) 959 4336, Fax: (808) 959 4323

Postharvest Calcium Drench Research

CaCl2, used as a postharvest drench on many apple cultivars, can increase calcium levels, reduce the incidence of bitter pit and other calcium-related physiological disorders, and improve fruit firmness, storage potential and packout.
Research has been carried out in the UK at HRI (East Malling) on postharvest application of the Phosyn product Stopit (a CaCl2 formulation) on Braeburn apples. Part of this research involved photographs being taken using a scanning electron microscope looking over the surface of apple tissue plugs. The research showed skin quality to be of major importance. Fruits with poor skin quality had an increased susceptibility to damage from CaCl2. Some fruits had uneven, broken skin from heat and drought stress, making them more susceptible to damage. Also, many of these fruits had high residues of CaCl2 on the skin from excessive spray applications preharvest which also put the fruits further at risk of damage. Visual examination of fruits before treatment may help in deciding whether to use posharvest calcium drench but apple skins can be sensitized without this being apparent to the naked eye.
Phosyn have now set international guidelines covering the postharvest application of Stopit on apples. These are listed in a booklet, which is part of a kit available to packhouse operators using Stopit in their drench plants. The kit consists of the booklet, guidelines and a sample bottle to test the dilution of the drench solution.
For further information contact:
Phosyn plc - Head Office, Manor Place, Wellington Road, The Industrial Estate, Pocklington, York YO42 1DN, UK. Tel: +44 1759 302545 Fax: +44 1759 303650 Telex: 57679, Email:
From: The Orchardist

Postharvest 2000. 4th International Conference on Postharvest Science, Jerusalem, Israel, 26-31 March 2000

A most successful International Society for Horticultural Science (ISHS) Symposium was held in Jerusalem, Israel, 26-31 March 2000. Convened by Professor Ruth Ben-Arie and her formidable Organizing Committee, this action-packed Symposium was appreciated and enjoyed by over 400 registrants from more than 40 countries. With scientific sessions spread over 3 days, separated by an excellent choice of 4 professional tours to various parts of this extraordinary diverse country, participants were fortunate to be exposed to a broad range of up-to-the-minute topics covering the broad range of subjects that comprise postharvest science.
Each day commenced with a plenary session in which a leading expert in the field gave an overview of pertinent and relevant subjects. Professor Don Grierson, University of Nottingham, UK, in his characteristically inimical style, provided an erudite and dispassionate (and sometimes passionate) outline of the advances and prospects made in biotechnology for postharvest. He outlined the potential for molecular biology to contribute to both an understanding of maturation and senescence processes that lead to postharvest problems in fresh products, as well as describing potential benefits that genetic manipulation holds for improving food quality and reducing losses in both developed and developing countries.
Dr Dov Prusky from the Volcani Research Center in Israel, provided an elegant and broad ranging discussion of mechanisms influencing susceptibility to diseases and the process of pathogenesis for postharvest pathogens in important horticultural crops. Drawing from a wide range of sources, as well as recent unpublished work in Israel, he was optimistic about the opportunities for modern technologies to help solve some of the basic conundrums still facing pathologists and suggested future research options for reducing food losses resulting from postharvest diseases.
Programmed cell death (is it or is it not apoptosis?), a topic receiving widespread attention in the animal research world, is also being examined increasingly in plants; it clearly plays a major role in physiological disorders, cellular responses to stress as well as the senescence process in fruits and vegetables. Dr Ian Ferguson, HortResearch, New Zealand, gave a laconic, fluent and incisive explanation of the subject, drawing heavily on experiments from his laboratory where the use of flow cytometry techniques is allowing ever more detailed investigation of cell death events derived from a number of different causes. Much more will be learned about postharvest problems and processes as this type of work is developed in laboratories utilizing such tools.
A timely reminder that quality in the eyes of the consumer constitutes many attributes and that flavour and aroma, as well as crispness and juiciness, will increasingly become key decision making features with buyers of fresh fruit and vegetables, was provided by Professor Adel Kader, University of California, USA. He reminded the audience that introduction of quality assurance systems to all crops was essential for the successful development and retention of markets, and that benefits were to be gained by developing systems that were consistent and took into account a wider spread of attributes than those commonly used today. The ability to segregate product lines as a result of non-destructive techniques for measuring quality in line, has become possible through the development of a range of technologies, some of which are now being introduced into commercial packhouses.
The remaining sessions were concurrent and covered the main topics of interest to postharvest scientists. Inevitably the importance of the Symposium topic (perhaps rivalled by the significance of the venue in this momentous year 2000) meant that there were a large number of oral and poster presentations that could only be presented in multiple or concurrent sessions. For those who were interested in all topics some difficult choices had to be made about which sessions to attend. However, all the sessions were well attended and the overall quality of both poster and oral presentations was excellent.

Overall there were 145 oral and more than 200 poster presentations. Topics dealt with in detail included: sensor technology and non-destructive quality assessment; developmental regulation from germination to senescence; texture and cell wall metabolism; preharvest effects on postharvest behaviour; plant growth regulators and ethylene; colour and pigmentation; volatiles including flavour and scent compounds; refrigeration; senescence; CA/MAP technology; coatings and waxes; biological control and host resistance; alternatives to chemical control of postharvest pests and diseases; quarantine related issues; freshcut produce; food safety; physiological disorders; postharvest trends in developing countries; future trends and postharvest science in the new Millennium.

In addition to the main programme, a representative from the EU outlined new programmes whereby collaborative projects between EU and developing countries might be funded with the objective of providing R&D support for projects that would improve both scientific expertise and food security in developing countries. This programme is commended to postharvest scientists in appropriate countries, who should actively seek funds to further postharvest R&D and associated technology transfer activities.

A Business meeting of the Postharvest Commission of the ISHS was well attended and final decisions were made as to the postharvest topics that will form the basis of Postharvest Symposia at the XVI International Horticultural Congress in Toronto 2002. Approval was given for the Commission to re-organize its structure to form two new Working Groups, one on Controlled Atmosphere Storage, (the next CA Conference to be held in Rotterdam, 8-13 July 2001), and the second to develop strategies for the Commission to become involved in postharvest science in developing countries. Finally the decision was made that the venue for the next Postharvest Symposium in this series will be in Verona, Italy in 2004 with Dr Pietro Tonutti being Convenor, assisted by Dr Fabio Mencarelli and the postharvest group within the Italian Society for Horticultural Science.

Professional tours were to the northern part of the country including Upper Galilee and the Golan Heights, the Lower Galilee, to see exotic crop production the southern desert and to visit the Postharvest and Storage Laboratory, Bet Dagan, Volcani Center. All participants appreciated each of these visits, having the chance to see a small part of what constitutes a very successful horticultural industry. In addition, most participants took the opportunity to visit both the old and new city of Jerusalem, made easier when His Holiness the Pope had completed his momentous visit to this special city.

This was an extremely successful Symposium, enjoyed by a large gathering of Postharvest scientists. Congratulations to Ruth Ben-Arie and her team for making this such a special event. Proceedings will be published in an Acta Horticulturae later this year. Further details can be obtained on the ISHS web site at

Errol W. Hewett Chair, ISHS Postharvest Commission

Postharvest Heat Treatments: Effects on Commodity, Pathogens and Insect Pests

Immediately prior to the ISHS Postharvest meeting in Jerusalem, a satellite meeting on Postharvest Heat treatments was held at Maagan on the shores of the Sea of Galilee, Israel, on 22-24 March 2000. This Workshop was hosted by BARD, (a cooperative agricultural research programme between Israel and the USA) and organized by Dr Susan Lurie, Volcani Center, Israel with the assistance of Dr Roy McDonald, USDA, and Professor Robert Paull, University of Hawaii.
Attended by about 50 participants from 15 countries, this was an excellent example of a highly specific meeting where all participants could interact professionally and socially, with time on the programme for ample discussion of the papers presented. Seventeen papers were presented ranging from reviews to reports of ongoing research.
A highlight of the Workshop was the mix of skills and expertise of participants. It is rare for truly multidisciplinary meetings to be organized these days as scientists become more and more specialized in their activities. But this Workshop was successful because it provided an opportunity for plant pathologists, entomologists, plant physiologists and biochemists, molecular biologists and engineers to listen to research and experiences of colleagues in different disciplines.
The programme consisted of 5 sessions. Professor Lutz Nover provided an elegant insight into the molecular complexities of the heat response in plants indicating how such primary events may be manifested as thermotolerance. This was followed by sessions on heat treatments of fruits and vegetables with overviews of the physiological, biochemical and cellular changes that occur following exposure to temperatures in the range from 38 to 55oC. Knowledge of the responses of plant pathogens and insects to heat is crucially important if we are to be able to replace chemical treatments with some form of heat application. A series of contributions outlined the varied responses that can occur depending on the time/temperature interactions as well as the importance of the host condition and the developmental stage of the organism.
It is all very well for scientists and regulatory authorities in different countries to come up with detailed recommendations for controlling pests and/or diseases on different products; it can be a different and difficult challenge to achieve such conditions on a commercial scale. Thus the experiences of an engineering company in establishing hot water treatment systems for treating mangoes in Central and South America were a salutary reminder to the participants that increasing the complexity of treatment protocols makes it increasingly difficult to achieve required quarantine conditions in spite of sophisticated computer-controlled systems.
Several important messages emerged from this Workshop. It is clear that in plants, pathogens and insects, a multiple range of processes is involved in responses to heat, but there is no one blanket response for all species. Production of heat shock proteins, while important and still an active topic of research, is not the only response occurring, and we must continue to explore other metabolic processes to identify critical points that may be amenable to manipulation. A strong case was made for re-examination of the role of membranes in heat responses; it is felt that perhaps they are not the key as has been widely believed, but the changes that occur may be a consequence of the stress or merely a reflection of its role as a sensor of the stress received.

It must be remembered that heat treatments can and will be used for different purposes including delay of senescence, reduction of decay and mortality of insects. Each should be examined separately as they will require different operating parameters for successful implementation. Such treatments will affect multilayered processes and hence each must be investigated both independently and then holistically. For example, it was shown that insects become conditioned very rapidly to heat, although this may be reduced by anoxia. Of particular interest was the development of mathematical models, based on models derived from extensive data sets, that have potential to be used to identify the most promising, efficient and user friendly quarantine solutions for industry.

The session on the technology of heating was particularly interesting. Scientists were reminded that their laboratory results always had to be scaled up to a large scale before they could be used commercially. Practical examples of some of the constraints and difficulties in achieving this were graphically presented with a plea to researchers to provide generic and relatively straightforward recommendations for treatments wherever possible.

Apart from the valuable networking that took place in this highly specialized but diverse meeting, 3 main messages emerged:

This was an excellent, high quality and productive meeting organized efficiently by Susan Lurie and her Organizing Committee. The proceedings are to be published in a special edition of Postharvest Biology and Technology later this year.
Errol W. Hewett, Chair, ISHS Postharvest Commission

CA Storage: Meeting the Market Requirements

The proceedings of the workshop on CA Storage: Meeting the Market Requirements held in August 1999 in Ithaca, New York, have been published by NRAES. The workshop surveyed key issues for fruit growers and storage operators and packers who aim to maximize market quality, especially those who have controlled atmosphere (CA) facilities or who are considering building CA facilities.
The publication includes papers on: Issues for the New York storage industry; Storage physiology 101: fundamentals of product response to CA; CA storage technology; New York recommendations for controlled atmosphere storage and application of diphenylamine; Ethylene technology: Ethylene scrubbing, ReTain, and MCP; Economics of CA storage; Postharvest decays: Research results and future directions; Packing house sanitation; Maintaining firmness of apples: and Effects of packing, cooling, and transport.
In addition to fruit growers, packers and storage operators, horticulturists, fruit and vegetable scientists, and specialists in related areas of agricultural engineering should find the book a useful new resource.
CA Storage: Meeting the Market Requirements (price US$16.00) is available from:
NRAES, Cooperative Extension, 152 Riley-Robb Hall Ithaca, New York 14853-5701, USA.

Email: WWW:


Heat Treatment Workshop

A hands-on workshop during which the Department of Grain Science and Industry's pilot flour mill and feed mill were heated to 120-130oF using electric and gas heaters, respectively, to kill insects was organized by Kansas State University on 4-6 August of this year.
The aim of the workshop was to provide practical information to the food and feed industry quality assurance personnel, consultants, pest control service technicians, educators and researchers on the use of extremely high temperatures for managing stored-product insect pests. Specific objectives aimed to:
 About 67 people, representing pest control companies, food industries, academia, government and regulatory agencies attended the workshop.
A CD-ROM containing formal presentations, digital images of heating equipment, temperature data, a list of participants, and images of participants was provided free of cost to each workshop participant. The CD-ROM also contains information and temperature and relative humidity data from heat treatment of the flour mill carried out on 24-26 June 1999. The CD-ROM and hard copies of presentations and other handouts (that are not on the CD-ROM) are now available for sale through the Department of Grain Science and Industry. The cost of the CD-ROM and handouts (arranged in a 3-ring binder) is $100.
The CD-ROM and hardcopies of workshop materials can be ordered from:
Heat Treatment Workshop (Subi), Department of Grain Science and Industry, Kansas State University, 201 Shellenberger Hall, Manhattan, KS 66506-2201, USA.
For further information and an order form see:

QPod System for CA Storage

The Postharvest Group of Lincoln Ventures is working on the development of a controlled atmosphere (CA) system for a New Zealand Company, QPod Systems Ltd.
The QPod System consists of individually controlled pallets of produce where the temperature, oxygen level and carbon dioxide level are monitored and controlled. Shipping is possible in standard 6 m or 12 m refrigerated containers. The system is developed primarily as a sea freight CA system, but can also be used in local storage. The QPod System should appeal to those exporting highly perishable crops who are seeking cost effective alternatives to airfreighting produce.
Lincoln Ventures offers research, development and consulting services in a variety of areas including postharvest engineering, sensors and biosensors, instrumentation, plant protection and water management.

For further information contact:

QPod Systems Ltd, PO Box 28786, Auckland, New Zealand.

Tel: 0 9 525 6346, Fax: 0 9 525 6746, Lincoln Ventures Ltd, PO Box 84, Lincoln University, Canterbury, New Zealand, Tel: +64 3 325 3700, Fax: +64 3 325 3725, WWW:


Conference on Postharvest Treatment of Fruit and Vegetables

The following topics will be covered at the conference on Postharvest Treatment of Fruit and Vegetables in Murcia, Spain on 19-21 October 2000:
Proposals for papers must be submitted by 1 February 2000 and final papers submitted by 1 July 2000.
For further information contact:
Dr F. Artés Calero, CEBAS-CSIC,  Avenida de la Fama 1, Apartado 4195, 30080 Murcia, Spain.
Tel: +34 68 21 57 17, Fax: +34 68 26 66 13

Developing small-scale postharvest and agroprocessing equipment for farmers

In 1994, the Sasakawa Africa Association (SAA), which funds and manages the Sasakawa-Global 2000 (SG 2000) programme, joined forces with the Nigerian-based International Institute of Tropical Agriculture (IITA) to work together in Africa to identify, develop and extend improved postharvest and agroprocessing technology to farmers.
Within this partnership, IITA identifies, generates and packages technologies based on needs assessment and available resources. It also trains extension personnel and manufacturers, and provides quality control on fabricated equipment. SAA and government extension and small industry development agencies demonstrate the technologies and train farmers and agroprocessors.
Manufacturers fabricate the equipment and make it available to customers. The SAA/IITA partners train manufacturers in fabrication methods and carry out quality control checks on the equipment produced.
Both farmers and agroprocessors take part in demonstrations and field testing as, according to IITA's research specialist Leonides Halos-Kim, their feedback on utility, adequacy and profitability of the technologies have proved to be invaluable guides to the suitability of the technology within the local environment.
The success of the partnership can be seen in the fully-trained 83 machinists, welders, mechanics and other technicians from Ghana, Benin, Burkina Faso, Ethiopia, Guinea, Mali and Togo. As a result, in addition to sales within their own country, manufacturers in Ghana and Benin have reported export sales to 6 other countries including Mali, Niger and Zambia.

The expansion of the SAA/IITA agroprocessing programme from Ghana and Benin across the continent to Ethiopia has highlighted differences in Africa's agricultural marketplace. In West Africa, where small private agroprocessing businesses have taken root, there is more food in the marketplace. Alternatively, Ethiopia does not have this agroprocessing base and food remains to be grown and prepared at home.

Following the introduction of a multicrop threshing machine in Ethiopia, IITA is also developing a prototype roller mill for use in Ethiopia. These roller mills process good texture flour from maize, wheat and barley and, with the inclusion of quality protein maize (QPM), would make a considerable nutritional impact, particularly in the Ethiopian highlands. QPM, a superior quality maize which was first discovered in 1963, has a high yield potential, improved resistance to diseases and insects and greatly improved nutritional value.

The agroprocessing programme is also developing elsewhere. SAA/IITA expect to see an expansion of the wet grinder in northern Ghana and its use in processing oil crops such as groundnuts, shea nuts and soybeans. There is also increased interest in agroprocessing in Guinea, particularly in the development of a new rice polisher.

The IITA cassava grater is proving popular in Ghana and Benin, where over 170 units have now been sold. The cassava grater is expected to be popular in other countries, in particular Mozambique and Guinea, where manufacturers' training has taken place. For demonstration purposes, Yamaha donated two 3.5 horsepower petrol engines to power the graters. These petrol engines are small, light and mobile and have lower maintenance costs than diesel engines. SAA/IITA have also found that women find the petrol engines easier to operate.

The challenge now being faced by SAA/IITA is to reduce the cost of the agroprocessing industry network in order to make it sustainable. For example, at present the cost of field demonstrations and operator training - filling a gap between farmers and manufacturers - is mainly covered by SAA. Operator training should in fact be considered as part of the manufacturers' cost of customer care. Manufacturers need to evolve their business operations to include this cost, thereby maintaining their links with their customers.

Furthermore, more effort is required to forge partnerships and to structure the work of partnerships. This will fill the missing link in bringing improved technologies to the target users - rural farmers and agroprocessors.

For further information on the Sasakawa Africa Association (SAA) and SG-2000 contact:
Rachel Fisher, Raitt Orr and Associates Tel: 0171 828 5961. Fax: 0171 828 0714.