Fruit coatings made
from reformulated shellac and sucrose ester have been shown to help maintain
fruit quality after harvest by promoting the growth of beneficial natural
yeast and bacteria populations on fruits. In trials at ARS Subtropical
Horticulture Research Station in Miami, Florida, in cooperation with Mantrose
Haeuser Co Inc. of Westport, Connecticut, application of shellac formulations
to grapefruits (cv. Marsh) facilitated higher epiphytic populations on
the fruit surface and delayed fruit decay in storage. The bacterial and
yeast populations help maintain fruit quality by competing more efficiently
than pathogens for nutrients, such as sugars and proteins, at a critical
early stage in the pathogen's development. Preliminary test results also
indicated that the coatings prevented off-flavours by allowing for a better
exchange of oxygen and carbon dioxide than commercial chemicals permit.
For further information
contact:
Raymond G. McGuire, ARS Subtropical Horticulture
Research Station, Miami, Florida, USA.
Tel: (305) 254 3641.Fax (305) 238
9330.Email: miarm@ars-grin.gov
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Improved
Potato Storage in Madagascar
The Vakinankaratra region
of Madagascar produces about 60% of the national potato harvest. Three
crops are grown per year: the main crop, rainfed from October to February:
the second rainfed crop of limited acreage from January to May; and the
irrigated crop from June to September. Prices are lowest in January-February
when the main crop is harvested. With adequate storage facilities, farmers
would not be obliged to sell their harvest immediately but could store
it until market prices improve. Experiments with storage systems have shown
consistently good results.
Under the ASARACA (Association
for Strengthening Agricultural Research in Eastern and Central Africa)
Technology Transfer Project, the Centre de dévelopment Rural et
de Recherche Appliquée (FFIAMANOR), with the support of scientists
from Centro Internacional de la Papa (CIP), is undertaking a project with
the aim of storing consumption potatoes for longer periods to fetch better
prices. The beneficiaries are the members of the farmers associations in
Vakinankaratra region where potatoes are the principal crop.
Selected farmer groups
were sensitized on improved storage systems and informed about their own
contribution towards the construction of the stores. The farmers were trained
and they contributed local materials, about a tenth of the total material
cost, plus their labour towards the construction of the storage buildings.
Five naturally ventilated potato stores were constructed. Strong partnerships
were established between the project and the farmer associations. The latter
were involved in the initiation of the project and the planning stages.
On average, 72% of the total cost was met by the project itself while the
beneficiaries contributed 28%.
Many other regions have
expressed demand for improved storage facilities. The availability of these
facilities has greatly reduced demand on transportation. Only small recurrent
costs for the maintenance of the storage chambers are needed, which the
farmers association themselves can meet.
This storage system could be expanded
to other crops.
For further information contact:
Director, FIFAMANOR, BP 198, Antsirabe
110, Madagascar. Tel: 261 2 4448954. Fax: 261 2 4449964.
From: AgriForum
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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: cwang@asrr.arsusda.gov
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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.
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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
Email: jwa@aloha.net
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