|
Abstracts
Session 1:
Trends in the consumption of fresh and processed citrus fruits
|
Panorama of the world citrus market:
the singular evolution of easy peelers
Eric Imbert, Cirad-flhor, France
Analysis of the world fresh citrus trade during the period 1970/2000
reveals strong growth, with the quantities traded increasing from
5.5 million to approximately 9.6 million tonnes.
This apparent dynamism should nevertheless be tempered. Indeed,
the growth observed is distinctly below the average for the fruits
group and well below that of products such as pip fruits, exotic
fruits or bananas. However, there are considerable disparities within
the different families making up the citrus group. Although the
performance of lemon and orange is disappointing, the rate of increase
was particularly strong for the easy peeler family. What is the
foundation-intrinsic to the citrus market-for this exemplary dynamism?
On the one hand, there is less competition between fresh and processed
fruits than for other citrus fruits such as orange and lemon. The
change in consumption patterns benefiting juices and other citrus-based
processed products has only had a small effect on clementines, mandarins
and hybrids.
On the other hand, real efforts have been made in varietal research,
making it possible to improve the quality of the fruits available
(no seeds, sugar content, etc.), especially at the beginning of
the season, enabling substantial increases in consumption. The development
of early clementines at the expense of satsumas is a good example
of this quality-based substitution in the EU. Furthermore, these
varietal innovations have also made possible a substantial increase
in the length of the sales season. The broad range of late hybrids
that hardly existed in the 1980s and was developed in the 1990s
now accounts for about 15% of winter sales on EU markets.
Finally, exporters have been particularly dynamic in the opening
up of new markets. The shipping of easy peelers from the Mediterranean
area was developed to eastern Europe and then to North America.
Likewise, southern hemisphere exporters have developed a counter-season
market, especially in northern Europe.
Will easy peelers continue to play a driving role in the future
? Competition from processed products based on easy peelers should
remain limited. Varietal creation is still active and should meet
expectations in more coloured, sweeter fruits at the beginning of
the season and fruits with fewer seeds at the end of the season.
Eastern European markets remain to be developed, especially for
late hybrids. Likewise, new prospects are emerging in the large
Asian consumer markets and there is room for the development of
the counter-season market in the EU.
|
Evolution of the fresh citrus fruits
demand
Frederik van der Monde, Univeg, Belgium
|
Community policy concerning citrus
Raimondo Serra, European Commission
|
Fruit and vegetables and preventive
nutrition
Catherine Nicolle **, Christian Rémésy
*
* Unité des Maladies Métaboliques et Micronutriments
- INRA Clermont-Ferrand / Theix , 63122 Saint Genès Champanelle,
France
** Vilmorin Clause & Cie, BP 1, 63 720 Chappes, France
The beneficial effect on health of fruit and vegetable consumption
is one of the important points that has emerged from epidemiological
studies performed in recent years. These plant products have an
effect on health through the non-energy fraction-fibres, minerals
and micronutrients. They can thus be considered as functional foods
but that have a very great diversity of impacts in the digestive
sphere, the liver and circulation. They contribute significantly
to the supplying of minerals and micronutrients, play a key role
in antioxidant protection, in fighting excess weight and also play
a major role in the prevention of the plurimetabolic syndrome. They
also have other specific effects through their alkali forming capacity
and their richness in varied plant micronutrients. For good protection,
in particular against cardiovascular diseases and certain cancers,
fruit and vegetable consumption must not only be sufficiently varied
but must also supply at least 10% of the total energy intake, i.e.
about 300 g fruits and 300 g vegetables.
|
Session
2: Breeding and certification of plant material: towards a new generation
of varieties |
The new clementine varieties
Francisco Llatser, Viveros Avasa, Spain
|
Varietal diversification in the
mandarin group: the promise of seedless hybrid triploids
P. Ollitrault *, D. Dambier *, F. Luro
**, Y. Froelicher **
* Cirad-flhor Montpellier, TA 50/PS4, 34398 Montpellier cedex 5,
France
** SRA Inra-Cirad, San Giuliano, 20215 San Nicolao, France
The quality of produce is becoming the essential criterion for
the fresh fruit market. The definition of organoleptic quality varies
in the different European countries. Breeders must therefore attempt
to develop a varietal range that can respond to the diversity of
these perceptions of organoleptic quality. Seedless fruits, easy
peeling, internal and external colour and regular peel contribute
to the definition of fruit quality. In addition to seedlessness
of new varieties, it is necessary to seek cultivars that are incapable
of pollinating self-incompatible varieties, and especially clementine,
which now forms most of the easy peeler orchards in production in
the Mediterranean area. The spreading of production in time is also
a very important objective of easy peeler group breeding programmes.
Thus, late varieties are particularly expected by the market.
In the light of these issues, French teams (CIRAD and INRA) have
concentrated their efforts on the diversification of the seedless
easy peeler range using criteria of high quality in order to extend
the production period and prevent the possibility of cross-pollination
with clementine. The search for sterility led them to move towards
the breeding of triploid cultivars. Plants with three sets of chromosomes
rather than two (diploids) are indeed known to display a high level
of sterility of both ovules and pollen. It is thus possible to devote
efforts on breeding in the field more effectively on other characters.
Various biotechnology-based strategies have been developed to obtain
triploid hybrids.
The first strategy consists of selecting spontaneous triploidisation
events. Numerous triploid mandarin, tangor (mandarin x orange) and
tangelo (mandarin x grapefruit) triploid hybrids were obtained after
controlled hybridisation, embryo saving and flow cytometry selection.
The first fruitings have confirmed the very low fertility of these
hybrids and fruits with interesting pomological and organoleptic
characteristics have been observed. The second strategy is based
on crosses between diploid and tetraploid varieties. The tetraploid
varieties are bred by somatic hybridisation or selected from nucellar
seed. Several tens of allotetraploid and autotetraploid hybrids
were obtained. The first flowering of some of these this year made
it possible to start the second stage of the strategy by pollinating
diploid varieties. Finally, a method for the fusion of diploid and
haploid protoplasts was applied more recently for the direct synthesis
of triploid hybrids by conserving the entire genetic make-up of
the preselected diploid cultivars. It is thus hoped that the breeding
of varieties with predefined characteristics can be guided more
effectively.
Following the first selection based on qualitative aspects, the
best hybrids resulting from these various strategies will be subjected
to varietal trials in order to appraise their agronomic potential.
As the juvenile phase lasts for 5 to 6 years, a minimum of 13 to
14 years must elapse between the hybridisation and the extension
of a new variety. Beyond the quality aspects, hybridisation is also
performed using parents known for their tolerance to African citrus
leaf spot in order to develop a varietal range tolerant to this
disease that causes considerable damage in sub-Saharan Africa and
is threatening the Mediterranean area.
|
Rootstocks, a key component in sustainable
citrus growing
C. Jacquemond *, F. Curk *, R. Zurru **,
D. Ezzoubir ***, T. Kabbage ****, F. Luro *,
P. Ollitrault *****
* SRA Inra-Cirad, San Giuliano, 20230 San Nicolao, Corse, France
** Consorzio Interprovinciale per la Frutticoltura, Cagliari, Sardinia,
Italy
*** Direction des Domaines Agricoles, Casablanca, Morocco
**** Domaines Abbes kabbage, Taroudant, Morocco
***** Cirad-flhor, TA 50/PS4, 34398 Montpellier cedex 5, France
Citrus form the world's leading fruit production, in a zone lying
between 40°N and 40°S. The Mediterranean area is the second
most important cultivation zone and displays a great diversity of
soil and climate conditions. A number of constraints are therefore
encountered, such as salinity, limestone and drought, at the same
place. With regard to crop health, tristeza is already present in
the Mediterranean and is a growing danger because of the massive
use of sour orange (Citrus aurantium L.) as rootstock. Finally,
the Mediterranean area specialised in the production and marketing
of fresh fruits. The fruit quality requirements for this type of
market form a considerable constraint and depend to a considerable
extent on the choice of rootstock. It allows the adaptation of the
varieties cultivated to soil and climate conditions and pest pressure
and also plays an important role in yields and the internal and
external quality of fruits. The INRA-CIRAD agricultural research
station (SRA) at San Giuliano in Corsica set up the first rootstock
breeding trials using clementine (Citrus clementina Hort. ex Tan)
in 1964. Nearly 160 rootstocks have since been tested and evaluated.
These 40 years of experience have made it possible to breed two
rootstocks for Corsica that outperform sour orange: Carrizo citrange
(Citrus sinensis (L.) Burm. x Poncirus trifoliata (L.) Raf.) and
Poncirus trifoliata cv 'Pomeroy'. The rootstocks have faster fruit-setting
and higher yields with comparable fruit quality to that induced
by sour orange. However, Corsica does not have the same constraints
as the rest of the Mediterranean and this is why San Giuliano station
is participating today in reflection on the replacement of sour
orange in other countries in the Mediterranean zone. The first results
of joint trials conducted in Morocco and Italy reveal considerable
differences in the behaviour of a rootstock in different locations.
These preliminary results show the need to continue multisite experimentation
and breeding work in the production zones. Solutions to the Mediterranean
abiotic constraints do exist in matters of rootstock but they are
not necessarily satisfactory in terms of resistance or tolerance
to pests and diseases and fruit yield and quality. The breeding,
evaluation and creation of rootstocks is more than ever a topical
area. Somatic hybridisation methods seem to be particularly suitable.
FLHOR-AG1 (common mandarin Citrus deliciosa Tan. + Poncirus trifoliata
(L.) Raf.), bred in such a programme, is already being studied and
seems to be promising in the face of the constraints of the Mediterranean
area.
|
The behaviour of traditional rootstocks
under abiotic constraints in Morocco
Driss Ezzoubir, Domaines Agricoles, Morocco
The Moroccan citrus sector is of great socio-economic importance.
Until very recently, practically all the trees were grafted on sour
orange rootstock. The latter is well suited to the various soils
and gave good agronomic performance and good fruit quality. However,
sour orange gives combinations that are susceptible to tristeza.
The latter is a serious threat to Moroccan citrus orchards. It is
essential to replace sour orange by other, tolerant rootstocks in
order to face up to the threat and conserve the citrus sector.
The lack of information about the behaviour of the new reputedly
tolerant rootstocks in the different production regions has meant
that a rapid change from sour orange has not been possible. The
constraints are numerous: lime soils, salinity, hydromorphic soils
and fears that the new rootstocks may not give the same quality
of fruits. As a result, growers have displayed reticence with regard
to the new rootstocks.
New rootstocks have been introduced accidentally or intentionally
in commercial plantations. Trials have also been set up. This means
that we have been able to monitor the advantages and disadvantages
of the various rootstocks in commercial plantations (vigour, start
of production, yield, grade profile, inner and outer quality of
the fruits, evolution of maturity, tolerance to lime soils and salinity,
susceptibility to Phytophthora, etc.) and to make recommendations
for growers.
Monitoring the behaviour of these rootstocks enables us to conclude
that sour orange can be replaced by other rootstocks without risks
and even advantageously. The importance of sour orange in new plantations
is decreasing today.
|
The Spanish varietal certification
system
Luis Navarro, J.A. Pina, J. Juárez, J.F. Ballester-Olmos,
N. Duran-Vila, J. Guerri, P. Moreno, C. Ortega, A. Navarro, J.M.
Arregui, M. Cambra, S. Zaragoza
Instituto Valenciano de Investigaciones Agrarias (IVIA), 46113-Moncada,
Valencia, Spain
The Citrus Variety Improvement Program in Spain (CVIPS) started
in 1975. It has the following objectives: a) to recover pathogen-free
plants of local cultivars by shoot-tip grafting in vitro (STG);
b) to import foreign genotypes through an STG based quarantine procedure;
c) maintain healthy genotypes in a Germplasm Bank; and d) to release
healthy budwood to citrus nurseries through a certification program.
Plants recovered by STG are biologically indexed by inoculation
to the following indicator plants: Mexican lime, Pineapple sweet
orange, Dweet tangor, Citrus excelsa, Etrog citron, and Parson's
Special mandarin. In addition, they are indexed by sPAGE or imprint-hybridization
for viroids, by PCR for Citrus leaf blotch virus, by dsRNA analysis
for viruses that produce dsRNA during their replication cycle, and
by tissue print-ELISA for Citrus tristeza virus. Only healthy genotypes
are included in the Germplasm Bank, which has a field collection
used for research and horticultural evaluation, a cryostored collection
for long-term maintenance, and a screen-house collection that is
used to release budwood to nurseries. It contains a total of 475
genotypes, 272 selected in Spain and 203 imported from other countries,
representing 43 Citrus species and 33 species from 17 Citrus related
genera. Release of healthy budwood from this program to nurseries
started in 1979. At that time, there were only 10 registered nurseries,
but in the last few years the number has increased to 39. For commercial
propagation all nurseries are using budwood from the Germplasm Bank.
Since the beginning of the program, about 92 million certified nursery
trees from this origin have been planted in the field. This represents
more than 75% of the Spanish citrus industry. The CVIPS has produced
a very high impact in the citrus industry. Virus and virus-like
diseases do not cause any significant damage in the new plantings
now and a wide selection of healthy material from the best varieties
are available for growers.
|
The implications of varietal protection
for operators
Françoise Dosba
UMR 1098, Biologie du développement des plantes pérennes
cultivées, ENSA.M - INRA, 2 place viala, 34060 Montpellier
cedex 1
The aim of the International Union for the Protection of New Varieties
of Plants (UPOV) is the protection of new plant varieties, and especially
Citrus. Any new variety for which an application has been made by
the breeder or his successor in title can be the subject of DUS
testing (for Distinctness Uniformity and Stability).The aim is to
demonstrate that the variety deposited is distinct from any other
variety, that it is sufficiently uniform and remains unchanged after
successive reproduction or multiplication operations. This examination
with a view to awarding a breeder's right is performed by bodies
competent in comparative growing tests and leads to the description
of a variety on the basis of pertinent, essential characters. The
material supplied for examination must be representative of the
variety and free of important pests or diseases that might affect
the expression of characters. Qualitative, quantitative or pseudo-quantitative
pomological characters are used to distinguish between varieties
and must be the subject of at least two observation seasons. New
types of character such as molecular characters are envisaged but
are not yet accepted by UPOV regulations. An international organisation
is being set up for DUS testing. Variety protection can be effective
at the national or international level. In France, the CPOV (Comité
pour la protection des obtentions végétales) handles
all applications for national protection, while the OCVV (Office
communautaire des variétés végétales)
in Angers records applications for protection throughout the European
Union. Discussion of the advantages of protection for operators.
|
Session 3:
Quality from the orchard onwards: the impact of pests and diseases
|
The present status of citrus pathogens
in the Mediterranean basin
Christian Vernière *, Luis Navarro **,
Joseph Marie Bové ***
* Cirad-flhor, TA 50/PS4, 34398 Montpellier cedex 5, France
** IVIA, Moncada, Valencia, Spain
*** INRA et Université Victor Segalen Bordeaux 2, BP 81,
33883 Villenave d'Ornon, France
Mediterranean citrus production is mainly dedicated to the fresh
market. The sanitary aspect of fruits may therefore greatly impact
the benefit of the producers. The Mediterranean Basin is still free
of the most important citrus diseases, but citrus must face endemic
and newly emerging pathogens.
Some existing pathogens may induce dramatic consequences and their
transmission by insects makes their control difficult. Two viruses
are responsible for citrus Tristeza and Vein Enation Woody Gall
diseases and the mollicute Spiroplasma citri causes Stubborn. They
are classified as quarantine organisms in the EC where they are
found in some countries. Other pathogens can induce symptoms on
citrus and their effects are noticeable under certain conditions.
They are only mechanically or graft transmissible agents. They include
the viroids responsible for exocortis and cachexia, the psorosis
virus and the virus-like agents inducing oak leaf patterns. The
propagation of material tested free from all these graft-transmissible
diseases makes it possible to decrease the inoculum and sometimes
eradicate some of these pathogens from the orchards. However, additional
strategies are necessary to lessen the impact of insect transmitted
agents.
Fungal diseases can lead to important fruit losses and tree decline.
Mal Secco, which is caused by Phoma tracheiphila, is a major problem
on lemons and citrons in certain areas of the Mediterranean Basin.
Phytophthora species, which cause gummosis and root rot, are endemic
in all the citrus producing countries. Appropriate cultural practices
and the use of tolerant rootstocks should control Phytophthora-induced
diseases.
Two viral diseases were recently described in the Mediterranean
Basin. Citrus Chlorotic Dwarf CCD appeared in the mid-1980s in Turkey
and mainly affects lemons, grapefruit and some mandarins. The CCD
virus is transmitted by a whitefly and induces chlorotic and variegation
patterns on leaves and stunting on early infected trees. The Citrus
Leaf Blotch Virus was detected during indexing of the Spanish citrus
quarantine programme from a kumquat cultivar inducing bud union
crease on Troyer citrange. It was later detected in other citrus
cultivars.
The quarantine, sanitation and certification programmes in some
Mediterranean countries have contributed to improving the sanitary
status of citriculture and to revealing new biotic constraints.
They will help to prevent the introduction of economically damageable
pathogens that cause serious epidemics in other citrus producing
regions: severe strains of CTV, Huanglongbing, variegated chlorosis,
citrus bacterial canker and Phaeoramularia fruit and leaf spot disease.
|
Mediterranean citrus pests
Serge Quilici
Cirad-flhor, Pôle de Protection des Plantes (3P), 7 Chemin
de l'IRAT, 97410, Saint-Pierre, La Réunion, France
Although the citrus crops in the Mediterranean area are subject
to attacks by fairly numerous pest species, only a small number
of these are likely to be key pests.
Among fruit flies, the Mediterranean fruit fly or Medfly, Ceratitis
capitata, is generally a cause of direct damage to numerous citrus
species and varieties. For many years, the methods used to control
this pest have been based on the placing of a combination of bait
and insecticide or, more recently, mass trapping using attractants
that are specific for females. The peach fruit fly, Bactrocera zonata,
which appeared a few years ago in Egypt, is also a major risk for
all the countries in the region.
Several aphid species can cause direct damage to citrus crops, but
the main risk in certain countries results from the ability of certain
species (in particular Aphis gossypii) to spread tristeza virus.
Scales are serious pests in numerous countries in the region, and
in particular a number of diaspine species and also certain Lecaniidae
and Pseudoccidae. They are generally controlled by mineral oil spraying
and sometimes insecticides. The citrus flower moth, Prays citri,
causes varying degrees of damage according to the country, sometimes
strongly affecting production and necessitating specific treatment.
The appearance of the citrus leafminer, Phyllocnistis citrella,
in numerous Mediterranean countries in the first half of the 1990s
resulted in much work on chemical and biological control methods
in order to adapt the integrated control programmes previously set
up. These generally contributed to a distinct improvement of the
situation. The impressive damage caused by the leafminer in the
years following its arrival is now considered to be limited in adult
orchards. Furthermore, various mites belonging to the Tetranychidae
(Tetranychus urticae, Panonychus citri) or Eriophyiidae (Phyllocoptruta
oleivora, Aceria sheldoni) families are regular pests whose control
often requires the one-off application of mineral oils or specific
acaricides.
|
Citrus leaf spot in tropical and subtropical
Africa: a threat for neighbouring regions?
Christian Vernière *, Jean Kuaté
**
* Cirad-flhor, TA 50/PS4, 34398 Montpellier cedex 5, France
** IRAD, Yaoundé, Cameroun
Citrus leaf spot, a fungal disease caused by Phaeoramularia angolensis,
is spreading rapidly in Africa. It was described in 1952 in Angola
and Mozambique and is now present in 19 countries in tropical and
subtropical Africa, reaching the Republic of Guinea in the west
and going northward in the east as far as Ethiopia and even the
Yemen. Citrus production in tropical and subtropical Africa (excepting
South Africa) totals some 4.9 million tonnes (FAO 1999-2000). In
tropical Africa, citrus fruits are a diversification crop in comparison
with cash crops and are generally grown in smallholding orchards.
They are a source of income through outlets on growing urban markets
and export sales. Furthermore, the European Union classifies Phaeoramularia
angolensis as a quarantine organism and prohibits all citrus imports
from contaminated regions.
Attacks cause 20 to 100% crop loss through deterioration or the
fall of early infected fruits. They can also lead to the depreciation
of the orchard as leaf fall causes the slow decline of the trees.
Expression of the disease can occur in zones whose altitude ranges
from sea level to 2,000 metres, but the most serious attacks occur
at between 600 and 1,000 m, which are also the zones that are favourable
for the production of high-quality fruits. Furthermore, chemical
control is the only strategy applied to attempt to reduce the impact
of the disease, but it pollutes and is expensive and hence poorly
suited to these developing countries.
Little work has been performed on citrus leaf spot. Research has
been conducted above all in Cameroon and also in Kenya. It has shown
that no resistance to the fungus exists; only satsuma, grapefruit,
lemon and kumquats display tolerance or low susceptibility. The
main commercial varieties (orange, grapefruit, mandarin) are susceptible.
Temperature and rainfall appear to affect expression of the disease.
However, very few data exist on the sources of inoculum, population
variability and the spread of the disease in time and space. This
poor knowledge of the fungus and epidemic factors means that citrus
leaf spot is a threat to neighbouring producer countries like South
Africa and those of the Mediterranean area.
|
Tephritid fruit flies (Diptera, Tephritidae):
pests of economic significance for citrus production
J.P. Cayol, W. Enkerlin, A. Bakri, J.
Hendrichs
Insect Pest Control Section, Joint FAO/IAEA Division for Food and
Agriculture, International Atomic Energy Agency, Vienna, Austria
The Tephritid fruit flies (Diptera, Tephritidae) of economic significance
are, for a large part, polyphagous species. The number of host plants
can vary from about ten to several hundred fruit varieties, as in
the case of the Mediterranean fruit fly or medfly, Ceratitis capitata
Wiedemann. Citrus species are often among the preferred hosts of
these tephritid fruit fly species. In many temperate, sub-tropical
and tropical countries, tephritid fruit flies are the major pests
of citrus, causing up to 80% losses when no effective control measure
is applied.
Medfly is the most important tephritid pest of citrus in the Mediterranean
Basin, but also in some Sub-Saharan countries, in the United States
of America (California and Florida), where it is a pest of quarantine
importance and is permanently monitored, and in some Latin-American
countries. In Central America, apart from the exotic medfly, the
major endemic tephritid pest of citrus is the Mexican fruit fly,
Anastrepha ludens (Loew), while in most of South America it is the
South-American fruit fly, Anastrepha fraterculus (Wiedemann). While
medfly is present on the Western coast of Australia, the Queensland
fruit fly, or Qfly, Bactrocera tryoni (Frogatt), is present on the
Eastern coast. In South-East Asia, the major tephritid pests of
citrus belong to the Oriental fruit fly, Bactrocera dorsalis (Hendel),
complex.
Several specific control methods have been developed and applied
successfully against tephritid fruit fly species. The Sterile Insect
Technique (SIT), developed in the 1950s, has been successfully used
against the medfly, the Oriental fruit fly, the Qfly, and the Mexican
fruit fly. The Male Annihilation Technique (MAT), based on the attractiveness
of methyl-eugenol or cue-lure for the males of several Bactrocera
species, was developed in the 1940s. The MAT has then been used
successfully, among others, against B. dorsalis in Hawaii and in
California. The Bait Application Technique (BAT), developed in the
1950s, though not as species-specific as the SIT and the MAT, has
been used against B. dorsalis in Hawaii. In Israel, the BAT, first
used in 1958, is until today the major control method used in commercial
citrus orchards throughout the country. In spite of the development
of these specific techniques, conventional control using cover sprays
of broad-spectrum insecticides is still used in some countries,
inducing resistance and major problems due to secondary pests such
as the citrus leafminer, Phyllocnistis citrella (Stainton).
In recent decades, the SIT and MAT were mainly used for the eradication
of the target tephritid species from a given area or country after
an outbreak of an exotic species of major economic importance had
occurred or from islands as in the case of Japan. Since the 1990s,
the constant efforts in the optimisation of the techniques, most
notably of the SIT, has paid off resulting in a cost-effective use
of such techniques for suppression, rather than only for eradication
of the target species. Consequently, the SIT is now often used as
a biological insecticide replacing the conventional control methods
for the areawide suppression of the target species, in combination
with other techniques, within an integrated pest management approach.
In some cases, these methods are even used on a preventive basis,
as is the case for the Preventive Medfly Release Programme in California,
or with the use of MAT against the peach fruit fly, Bactrocera zonata
(Saunders), in Israel.
The various aspects of tephritid fruit fly as major citrus pests
worldwide and the various control methods and strategies are reviewed
and discussed.
|
Session 4:
The labelling policy in Corsica and Spain
|
Promotion policies in the citrus sector
Octavio Ramon, President of CLAM, President of CGC, Vice-President
of Intercitrus, Spain
|
An example of segmentation by origin:
the PGI for Corsican clementine
Dominique Agostini* , JA. Prost**, F. Casabianca**, J.
Bouffin*
* Station de Recherches Agronomiques (SRA) INRA-CIRAD - San Giuliano
- Corsica
** Laboratoire de Recherche sur le Développement et l'Elevage
(LRDE) INRA - Corte - Corsica
Clementine forms an important proportion of the economy of Corsica.
For many years, marketing fruits with leaves-forbidden for the other
origins-enabled it to be very profitable. The leaf became the symbol
of Corsican clementine. Furthermore, as Corsica is the only citrus-producing
region of metropolitan France, national regulations were decentralised.
A change in European phytosanitary regulations in 1993 meant that
Corsican growers lost their exclusive right to sell clementines
'with leaves'. Meanwhile, certain producers' groups had encouraged
the planting of Spanish cultivars reputed to be more productive.
This strategy of imitation exposed them to fierce competition with
the countries with low production costs (Spain and Morocco). From
1994 to 1998, a research programme that included a study of the
sector aimed at identifying the reasons for the very poor sales
of the product that had led to a real danger for the Corsican production
system (Agostini et al., 1996; de Sainte Marie et al., 1999). The
decreased confidence of consumers and traders (at various levels)
in the product expected had become the main reason for lack of interest
to the advantage of other origins. The causes of the extreme variability
of the quality of commercial batches that tarnished the traditional
image of clementines grown in Corsica lay as much in cultural practices
and the modes of organisation formed by local packing and marketing
structures as in the different forms of relations between the stakeholders.
The presentation of these results in a technical meeting in June
1999 triggered brutal awareness. Guaranteeing the identification
of a specific product with a production zone requires the mobilisation
of the appropriate legal and institutional measures. The Corsican
citrus growing profession therefore undertook a certification process
with a request for a PGI for 'Clémentine de Corse'. In fact,
the setting up of such a sign of recognition does lead to identifying
a clementine market segment, making it possible to avoid a situation
of potential competition and achieving better product sales.
|
Session
5: Innovative juice production techniques
and the bioavailability of micronutrients |
Constraints and prospects for citrus
juice treatments
Max Reynes
Cirad-flhor, TA 50/PS4, 34398 Montpellier cedex 5, France
Consumer demand for processed products whose qualities are close
to those of fresh fruits is increasingly strongly in fruit juices.
Pure juices are gaining the edge on nectars, for example. Indeed,
the organoleptic and nutritional aspects are becoming determinant
criteria in the choice of extraction, stabilisation and concentration
technologies and also in packaging so that high quality products
can be ensured for consumers.
Citrus juices are very rich in micronutrients and vitamins and are
used as an example to show the different possible stabilisation
pathways for guaranteeing product quality-both nutritional and organoleptic-for
consumers who are usually far from the production zone.
The prospects of new processes will be mentioned in order to glimpse
the lines of co-operation and research that could develop between
the main stakeholders in the citrus sector.
|
Application of the vacuum flash-release
process to citrus for the preparation of purées, nectars
and essential oils
Pierre Brat
Cirad-flhor, TA 50/PS4, 34398 Montpellier cedex 5, France
Vacuum Flash-Détente®(flash release), a new alternative
to traditional blanching/crushing, is a process consisting of heating
the material (fruit, vegetables) to 60-90°C and then placing
it under a vacuum chamber (30-50 mbar). On release, the instantaneous
evaporation of a proportion of the water content (approximately
10 %) causes a break-down of the material as a result of expansion,
with the formation of intercellular micro-channels.
This adiabatic process applied to lemons has given, after refining,
purées with specific characteristics in comparison with juices
and purées prepared using a traditional process. The consistency
and viscosity of Flash-Détente® purées
are distinctly better than those of reference products as part of
the outer coating of the fruits is incorporated, giving higher cell
wall contents, and also because of the increase of intercellular
space in the middle lamella. The colour of Flash-Détente®
purées is also paler and more intense because of the incorporation
of whitish tissues (albedo) from the outer envelope of the fruits;
however, bitterness must be removed from Flash-Détente®
purée.
Finally, essential oils have been recovered from citrus peel (lemon,
sweet orange, mandarin and grapefruit) by the Flash-Détente®
process with comparable yields to those of traditional extraction
processes. Their terpene contents are higher and oxygen compound
contents are lower in comparison with cold-pressed oils.
|
Membrane technique application in the
processing of tropical fruit juices
Manuel Dornier
Cirad-flhor / Ensia-Siarc, TA 50/PS4, 34398 Montpellier cedex
5, France
Tropical fruit juices are an important economic issue for numerous
producer countries. Indeed, local and export markets have grown
continuously for several years. However, demand is focusing on fruit
juices with good sensorial and nutritional qualities and an increasingly
diversified range of products. Membrane techniques have considerable
potential in this context. They are often more respectful of the
fruit juice quality than conventional processes. Furthermore, some
are of great interest for the development of new products. The work
conducted since 1995 is aimed mainly at evaluating three membrane
techniques with the prospect of industrial use: tangential microfiltration
over ceramic membranes for the clarification or cold stabilisation
of pulpy tropical fruit juices, osmotic evaporation for low temperature
juice concentration and, more recently, electrodialysis for the
deacidification of particularly acid juices.
For the production of clarified fruit juices, tangential microfiltration
has the advantage of being a continuous operation. The use of an
appropriate membrane also makes possible the total retention of
microorganisms and hence the stabilisation of the product without
heating. Most tropical fruit juices are very rich in pulp. Combination
with an appropriate enzymatic treatment (free enzymes or enzymes
fixed in a bioreactor) is proposed to reduce viscosity and membrane
fouling. We have shown that it is possible after the optimisation
of treatment conditions to obtain clarified juices of interesting
quality using numerous fruits such as passion fruit, mango, banana,
citrus fruits and pineapple.
Concentration is an operation of prime importance in the tropical
fruit juice industry as it makes it possible to limit transport
and storage costs. Heat evaporation is the concentration technique
most commonly used today. Although it is performed under vacuum,
the technique always results in a deterioration of product quality.
Osmotic evaporation, a new cold concentration process, is being
studied for better conservation of the qualities of fresh fruits.
The technique consists of placing a hydrophobic porous membrane
between the fruit juice to be processed and a concentrated saline
solution. The difference in the activity of the water in the two
solutions creates a vapour pressure gradient in the membrane pores,
which remain filled with water. This
spontaneous phenomenon causes a transfer of water from the fruit
juice to the brine without heating being required. Tests performed
at from 25 to 30°C on various fruit juices show that this technique
can be used to produce a soluble dry extract of at least 60%. The
evaporation flows obtained are close to 0.6 kg.h-1.m-2 under industrial
conditions and some 10 kg.h-1.m-2 in the laboratory. Sensorial analyses
show improvement of the colour, taste and aroma of the fruit juice
in comparison with heat concentration. Product vitamin C is conserved
as the process temperature is low.
The very high acidity of certain fruits such as passion fruits limits
use of the juice for adding aroma to beverages, for example. The
development of deacidification techniques that conserve the aromatic
characteristics of the initial juice should make it possible to
develop products that are better suited to this type of use. Ongoing
studies show that electrodialysis has strong potential in this field.
The technique is being evaluated using different configurations
(homopolar and bipolar membranes) and makes it possible to deacidify
products without significantly changing the aromatic profile.
|
Innovations in citrus peeling technology:
commercial development of fresh cut citrus
Mohamed A. Ismail, FDOC, USA
Fresh cut fruits and vegetables are among the fastest growing categories
in the food industry. In the U.S., sales of fresh-cut produce reached
$12 billion in 2000 (Produce Marketing Association, 2000), and more
than doubled from $5 billion in 1995 to $10.5 billion in 1999. Fresh-Cut
fruits and vegetables are increasingly more visible in the produce
department of most supermarkets. Attractively packaged watermelon,
cantaloupe, pineapple and honeydew melons are at the top of fresh-cut
fruit category. Consumer demand for convenience is the driving force
behind this phenomenal growth. Citrus fruit, however, did not participate
or contribute to the growth of the fresh-cut fruit category.
The decline in consumption of fresh citrus, particularly grapefruit
in the U.S. prompted the Florida Department of Citrus to initiate
a project aimed at developing a citrus peeling machine to enhance
convenience and increase consumption. In 1998, a single tabletop
peeling unit/head was built and tested on water infused fruit with
limited success. Heinzen Manufacturing International of Gilroy,
California constructed a two-head peeling system consisting of a
hopper, a two-lane singulating conveyor and a PLC indexing mechanism.
The two-head system was tested on enzyme-softened 'Valencia' oranges
and grapefruit, and was successful in peeling 50 fruit per minute.
The new peeling unit is relatively small with a footprint of approximately
1ft2 (0.09m2). It consists of a set of six blades mounted on spring-loaded
stainless steel members. The blades score the peel to a depth of
1-2mm. As the fruit clears the blade mechanism, it is impaled with
a six-member barb mechanism, which removes the peel from the majority
of the fruit. A special roller conveyor separates the peel from
partially peeled fruit.
The peeling machine is patented by the Florida Department of Citrus
and its domestic usage was granted to two United States companies,
Del Monte Fresh Produce of Coral Gables and Golden Groves of Fort
Pierce, Florida. Del Monte will soon be installing a citrus peeling
system in Florida with a projected capacity of approximately 2700kg.
peeled fruit per hour. Licensing of the peeling machine for use
overseas is still open.
|
Market News
Service - FruiTrop Journal
Cirad-flhor - TA 50/PS4 - 34398 Montpellier cedex 5 - France
Tél : 33 (0)4 67 61 71 41 - Fax : 33 (0)4 67 61 59 28
|
Centre de coopération internationale en recherche agronomique
pour le développement Flhor - Département des productions fruitières
horticoles catherine.sanchez@cirad.fr
© Cirad 2003 | | |