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Cultivation of Olives in Australia

  • Australian Oils Research
Cultivation of Olives in Australia
Rodney J. Mailer
Australian Oils Research
1. Introduction
Australia, by European standards, is a very young country with the first European settlers
arriving as recently as 1788. Olives were not native to Australia but it took only a short time
before the species was introduced. The first introduction of an olive tree to Australia was in
1800 (Spennemann, 2000), 12 years after the country was settled. Other importations have
been recorded into New South Wales (NSW) including a tree planted by John Macarthur,
one of Australia’s pioneers and a man considered to be the father of the Australian sheep
wool industry. A remaining olive tree still stands at Elizabeth Farm where he lived.
Despite the early start in the new settlement in NSW, little development occurred in that
state over subsequent years. As the colony moved to other areas in Australia, olive
production was spurred on by European immigrants particularly in the states of South
Australia and Victoria. The NSW Department of Agriculture was formed in 1890 with an
agenda to introduce new and useful species and study orchard farming and animal
husbandry. The Department established experimental farms at sites throughout NSW
including Wollongbar and Hawkesbury which became sites for evaluating olive production.
In 1891 several Department of Agriculture research stations established schools and
experimental farms including one at Wagga Wagga in Southern NSW, which included olive
One of the most significant early developments for the olive industry was through the
efforts of Sir Samuel Davenport (1818 – 1906), one of the early settlers of Australia, who
became a landowner and parliamentarian in South Australia. His father was an agent of the
“South Australia Company” in England and purchased land in South Australia. Samuel and
his wife Margaret went to Australia in 1843 and ventured into mixed farming, almonds and
vines. He tried sheep-farming and in 1860 he bought land near Port Augusta, SA, and
turned to ranching horses and cattle. Davenport strongly promoted agriculture in South
Australia and between 1864 and 1872 he published a number of papers, some concerning
the cultivation of olives and manufacture of olive oil ( In 1891 Davenport
provided the NSW Department of Agriculture and other parts of the colony with olive
cuttings from four cultivars, Verdale, Pigale, Blanquette and Bouquettier, from the south of
France which were trialled for fruit production at the experimental farms.
In 1894, the farm at Wagga Wagga established orchards for evaluation of various fruits
including plums, pears, persimmons and others. It was decided to establish a complete
collection of olive cultivars within that orchard (Wagga Wagga Advertiser, 14 June 1894
Olive Oil – Constituents, Quality, Health Properties and Bioconversions
from Spennemann 2000). Spennemann reports (2000) that by 1895, 8 acres of olives had
been sown in Wagga Wagga “which now had the finest collection of cultivars in Australia”
including many from California. By the turn of the century approximately 60 cultivars were
present in the Wagga Wagga collection.
In future years significant studies were carried out on oil production and fruit pickling
based on cultivars including cvv: Amelau, Blanquette, Bouquettier, Boutillan, Corregiola,
Cucco, Dr Fiaschi, Gros Redondou, Macrocarpa, Nevadillo Blanco, Pigalle and Pleureur.
Small scale commercial production and sales occurred after 1900 with the sale of olive oil
and the distribution of olive cuttings for orchard development.
New cultivars continued to be introduced and the grove at Wagga Wagga expanded over
subsequent years with several lines brought from Spain in 1932. Despite the excellent
collection which had been established at Wagga Wagga, in 1959 it was decided to remove
many of the trees due to low demand for the product. Although one of each of the cultivars
was to be retained, subsequent loses through trees dying or being removed resulted in
confusion about tree identification.
Fig. 1. One of over 100 trees and 60 cultivars planted at the Wagga Experimental Farm in
There was resurgence in interest in olive production in 1995 with the formation of the
Australian Olive Association. At that time, Charles Sturt University, which had taken over
ownership of the olive collection, made an attempt to resurrect the grove. The trees were
severely pruned back from the massive size to which they had grown. A project funded by
Rural Industries and Research Organisation (RIRDC) (Mailer & May, 2002) analysed DNA
from leaves of the individual trees using RAPD analysis to attempt to identify the collection.
This study was successful in naming many of the trees but for others there were no matches
and identification was not possible. Some of the trees by this time had been named by areas
in which the cuttings had been taken, such as Pera Bore or Hawkesbury Agricultural
College, although logically, they were of European origin. At the same time, research on
yield, oil content and oil quality was being carried out.
Based on this research, together with data from the original maps and planting diagrams,
the Wagga Wagga orchard became the source of cuttings for some of Australia’s leading
Cultivation of Olives in Australia 213
nurseries. Many trees were propagated and sold to new growers. Despite the best attempts
to ensure correct identification, many of these new trees were misidentified and created
problems for new orchardists in future years.
Amelon Dr Fiiaschi Pecholine
Arecrizza Frantojo Pecholine de St Chamis
Atro Violacca Gros Redoneaux Pendulina
Attica Hardy’s Mammoth Pera Bore
Attro Rubens Hawkesbury Agric. College Pigalle
Barouni Large Fruited Polymorpha
Belle d’Espagne Lucca Praecox
Big Spanish Manzanillo No.14 Regalaise de Languedoc
Blanquette Manzanillo No.2. Regalis
Borregiola Marcocarpa Rubra
Bouchine Nevadillo Blanco Saloma
Bouquettier O de Gras Sevillano
Boutillon Oblitza Tarascoa
Columella Oblonga Verdale
Corregiolla Oje Blanco Doncel
Cucco Olive de Gras
Table 1. Olive Cultivars included in the historic Wagga Wagga Olive Grove. NB. Names and
spelling of cultivars are from the Spennemann report (1997). Some names are descriptive (e.g. large
fruited) or the source of cuttings (e.g. Pera Bore).
Despite an early start, for over 100 years olive production showed only minor indications of
becoming a substantial crop in Australia. Olive oil production remained only a boutique
industry with the bulk of olive products being imported, almost entirely from Spain, Italy
and Greece. There were several feasibility studies carried out which indicated a potential for
an olive industry. These included a report published by Farnell Hobman (1995), a Senior
Research Officer with the South Australian Department of Primary Industries, on the
economic feasibility of olive growing. This reported stimulated further interest.
Olives today are planted throughout Australia, from the most southern point of Western
Australia to the northern tropical areas of Queensland (Fig. 2.). The trees have been found to
be capable of surviving in a wide range of environments from hot tropical regions to the
cold areas of Tasmania. Over many years, birds have spread seeds across the land around
many of these established orchards and numerous feral trees now grow throughout olive
production areas, reinforcing the suitability of the Australian environment to grow olive
trees. Studies to select for new cultivars from these wild trees (Sedgley, 2000) failed to
establish any outstanding new cultivars. These wild trees are now considered a pest to
native flora and in some States have been declared noxious weeds.
Olive Oil – Constituents, Quality, Health Properties and Bioconversions
Fig. 2. Olive growing regions and intensity in Australia.
Today, the Australian olive industry is a modern production system for excellent quality oil.
High yields have been achieved with low production costs. It is estimated that in the late
1990s, Australia had only 2,000 hectares of traditional olive groves, producing about 400
tonnes of oil. By 2008, Australia produced approximately 12,000 tonnes of oil. By 2013 it is
expected that this production will have doubled. Most of this new oil production comes
from 30,000 hectares of modern olive groves planted since 2000. There have been significant
improvements in mechanical harvesting to achieve high levels of efficiency and economy
which is comparable with any in the world. In traditional olive growing regions mechanical
harvesting using trunk shakers was once considered as the best and most reliable method
for reducing labour costs over the past decade. Today, continuous straddle harvesting
machines are used which have been adapted or developed for Australian conditions with
great success. These are currently used for more than 75% of Australian production.
Cultivation of Olives in Australia 215
Australia produces mostly extra virgin olive oil. The natural diversity of the Australian
environment along with the selection of the most productive cultivars, harvested and
processed under optimal conditions, is responsible for the exciting range of high quality
olive oil products from Australia.
2. Formal development of an Australian Olive Association
The first national symposium on olive growing was held at the Roseworthy Campus of the
Adelaide University in 1994, with strong interest spurred on by the economic feasibility
report by Farnell Hobman (1995). The symposium was attended by over 100 participants. A
decision was made to form an “olive industry group”. Over the next two years this olive
group drafted a constitution which was to become the Australian Olive Association (AOA).
The AOA committee had identified several issues which were critical to the development of
a new industry (Rowe and Parsons 2005). These included:
The lack of any Australian or State quality standard for olives
A lack of knowledge about cultivars suited to the large range of environments
Strong optimism about growing olives in Australia
A network needed to be established for the free transfer of information.
The constitution was adopted by the committee in Mildura in May, 1995. Of the 100
participants at that meeting, 65 became members of the new AOA. The committee adopted a
number of objectives:
a. To promote interest in olive growing and processing
b. To foster cooperation between regional groups
c. To facilitate research
d. Encourage education and information
e. Develop and distribute superior genetic olive material
f. Market research and promotion
g. Quality assurance
Following the formation of the AOA, several State industry organisations were then formed.
The first publication of the AOA magazine, the Olive Press, was printed in 1995. By the end
of 1995 regional grower groups had been established in Queensland (Qld), New South
Wales (NSW), South Australia (SA) and Tasmania (Tas).
The International Olive Oil Council (IOC) provided assistance to the developing industry in
Australia. The IOC funded olive experts to attend workshops held in Wagga Wagga NSW
and Roseworthy, SA and provided information to further encourage the industry in
Australia. This included the development of Australia’s first organoleptic panel, in South
Australia in 1997. The AOA and State Departments also held industry and grower
workshops throughout the country on oil quality and production.
The AOA developed a five year strategic plan for the industry in 1997. This plan described
the AOA as an “umbrella organisation” with a national industry structure (Rowe & Parsons
2005) overseeing State grower groups. In 1999 the Association was well established with
the creation of 27 Regional Olive Associations and 1000 members.
Olive Oil – Constituents, Quality, Health Properties and Bioconversions
The AOA made a commitment to establish an Australian standard. Existing international
standards were based on oil produced under limited environmental variation, particularly
in Mediterranean climates, and failed to recognise the natural variation in Australian olive
oil. The AOA, together with the Australian Government and international organisations has
been able to illustrate the high quality of Australian oil and the limitations of existing
standards. The Australian standards were approved by Standards Australia in June 2011.
Today the Australian Olive Association Limited is recognised as the Peak Industry Body in
Australia for olive growers. In its own words “The Australian Olive Association (AOA) is the
national body representing the Australian olive industry. Formed in 1995 as a result of a burgeoning
industry that recognised the need for collective action in developing and supporting the industry, it
now represents over 800 people nationwide. Members are involved in all aspects of the Australian
olive industry, from grower (small and large), processors to end-user and associated business partners
and service industries” (
The Australian Olive Association exists to:
set and maintain quality standards for Australian-produced olive products
provide quality research & development to create and maintain a sustainable integrated
olive industry
implement an ongoing consumer awareness programme to promote the benefits, and
create a preference for Australian olive products
provide a focal organisation which facilitates progressive direction for stakeholders in
the olive industry.
The AOA holds an annual conference (Expo) within Australia to address the latest
technology and research. The National Extra Virgin Olive Oil and the Australian Table Olive
Competitions are held concurrently with the Expo to highlight the quality of Australian
olive products.
3. The code of practice
One of the major outcomes of the AOA has been a Code of Practice. This was developed to
ensure to consumers that signatories to this Code have undergone rigorous procedures to
certify that the contents of a bottle of olive oil being sold is indeed Australian extra virgin
olive oil. Signatories to the Code of Practice are listed on the Australian Extra Virgin
website. To conform to the code of practice, producers must apply for registration and have
their oil tested to ensure it meets specific criteria.
Australian extra virgin olive oil must have the following characteristics:
be produced only from olives grown in Australia
have a free fatty acid content of not more than 0.8 grams per 100 grams (as oleic acid)
have a peroxide value of less than 20 (mEq peroxide oxygen per kg of oil)
not exceed the following extinction coefficients for ultra-violet absorbency tests:
An absorbance value at 270nm of no greater than 0.22
An absorbance value at 232nm of no greater than 2.5
A K value of no greater than 0.01
Cultivation of Olives in Australia 217
have been assessed organoleptically by a person or persons accredited by the
Australian Olive Association Ltd or in accordance with processes determined by the
Australian Olive Association Ltd as having positive attributes such as fruitiness and not
having any defects including fusty, muddy, musty, rancid or winey characteristics.
The chemical analyses for these purposes shall be undertaken by a person or organisation
accredited by the Australian Olive Association. A sample from each batch identified on
labels needs to meet the above tests before the claim that the oil is Australian extra virgin
olive oil can legitimately be made. Inclusion of a ‘best before’ date on a label shall not be
more than the equivalent of 30 days for every hour of the oil in Rancimat® at 110°C. Where
the oil is a blend and the constituent oils have been tested separately the ‘best before’ date
shall be that for the lowest scoring constituent.
In 2010 there were 230 Australian producers signed up to the Code of Practice including
grocery retailers who use the Code as an internal standard for extra virgin olive oils
4. Interaction with the International Olive Council
The Australian olive industry has learnt and benefited from input from the IOC and continues
to work with their members. Both chemists and producers utilise the IOC website and advice
from the IOC technical experts. Australia has two chemical laboratories and sensory laboratory
which continue to participate in the IOC proficiency program. The laboratories utilise IOC
methods of analysis and generally follow the limits of IOC standards.
The IOC initially provided funding for representatives to attend IOC meetings and during
the 1990s the Australian Government Analytical Laboratories (AGAL), Sydney, gained IOC
accreditation. Unfortunately, this provided no support for the industry due to a lack of
contact between the two organisations.
In 1996 the NSW Government laboratory at Wagga Wagga pursued accreditation for the
laboratory and in 2005, with funds from Horticulture Australia Limited, the organoleptic
laboratory was also accredited (Mailer, 2005a). In 2007 the Modern Olives laboratory in
Victoria also gained IOC accreditation. The sensory panels and chemical laboratories
provide the industry with a resource to monitor quality and to meet the stringent
requirements of the IOC and international standards.
During the period through 1995 - 2000, the IOC helped raise awareness of the health benefits
of olive oil. Partly, as a result of the Olive Council’s interaction, olive oil imports increased
in Australia from 7 million litres in 1978 to 15 million litres in 1992 and to 30 million litres by
2000. The IOC continues to play a role in the Australian industry. Accredited Australian
chemists are invited to attend chemists meetings in Madrid and the laboratories are invited
to participate in proficiency programs and ring tests in the development of new methods.
5. Codex alimentarius
During the early years of the olive industry, although Australian growers were producing
high quality olive oil, it was recognised that there were minor differences in the chemical
profile of oil from olives grown across the range of Australian environment. These oils had a
Olive Oil – Constituents, Quality, Health Properties and Bioconversions
spectrum of flavours and qualities not apparent in olives grown in the limited
environmental fluctuations of the Mediterranean climate. The first workshops in Wagga
Wagga in 1996, identified linolenic acid levels from 0.6 – 1.8% whereas the IOC standard for
olive oil was <1.0%. Many studies have shown that fatty acid profiles are strongly
influenced by environment, particularly the temperature during fruit development.
Although insignificant in value, and no problem in terms of nutritional quality, this factor
needed to be considered within international standards.
Further studies at WWAI in subsequent years showed other chemical parameters to
sometimes vary from the existing and restrictive limits of the IOC standards (Mailer,
2007). Some cultivars being grown in Australia, particularly cv Barnea, from Israel,
contained up to 5% campesterol whereas the limit imposed by IOC was <4.0%. These
limits, developed as a means to detect adulteration, have no bearing on the nutritional
value in olive oil. These components became a limitation for exporters of Australian olive
oil but it became apparent that not only did Australian oils fail to meet these standards
but many countries from the Southern Hemisphere (Argentina, Australia, Chile and New
Zealand) also failed.
Through Food Standards Australia and New Zealand (FSANZ) Australia has attempted to
have these limitations in the standards amended so that the standards represent olive oil
grown throughout the world. Over several years Australia has sent representatives to Codex
meetings to discuss these issues. IOC have responded vigorously, defending the standards
on the basis that changes will encourage fraud, despite the fact that genuine oils, such as
those growing in countries in the Southern Hemisphere, fail these limits. Due to the lack of
agreement Codex have failed to come to a conclusion and particularly, an accepted level for
linolenic acid in virgin olive oil has not been agreed upon.
6. An Australian standard
The lack of an Australian standard left Australia exposed to a lack of control of imported
product as well as limitations for the domestic industry. Until recently no testing was done
within Australia on imported olive oil. Several recent studies of imported olive oil products
taken from supermarket shelves has illustrated that a significant proportion of it does not
meet the international trade standards of IOC and Codex Alimentarius. Similar recent
studies have shown that many imported oils into the USA do not meet European and
international standards (Frankel et al 2011).
Surveys of Australian olive cultivars have been used to determine compliance with
international standards (Mailer et al, 2002). Reports show the effects of olive cultivars, the
influence of harvest timing and the changes to quality as a result of site and seasonal
growing conditions.
From the first inception of the Australian Olive Association, it has been recognised that
Australia must have its own standards for olive oil. The standards are required to set
guidelines for Australian producers to ensure the oil was authentic and of acceptable
quality. It was also critical to allow authorities to determine if the imported and local
product meets the quality levels demanded by the industry and the consumers. The
Cultivation of Olives in Australia 219
standard was created with consultation within the industry including producers, marketing
and exporters. It needed to address issues of authenticity, to detect any efforts to blend or
mislabel the product. It needed also to be able to detect oil which had been heated and/or
refined or if the oil had exceeded its potential use by date.
The standard was established with the support of Australian Standards organisation
( A wide spectrum of representatives from the industry contributed.
A final draft was made available to the public for comment in early 2011. The draft drew
both praise and criticism from all aspects of the industry both domestically and
internationally. Ultimately it had strong support and was accepted with the final standard
approved in July 2011 for release during 2011.
The new standard is similar in many ways to that of the IOC. The standard allows for a
higher level of linolenic acid and campesterol, reflecting the actual properties of the
Australian product. It has also included some new tests developed by the German DGF
which allow traders to identify fresh oil from old oils or oil which has undergone heating,
such as in refining. The standard is available from Standards Australia.
7. Consumption and production
7.1 Development of a boutique industry
In the early years of Australian settlement, there was not a strong demand for olive oil.
Olives were grown for personal use or for a small boutique industry. The major edible oils
used continue to be refined sunflower, cottonseed and canola oil. It was not until the late
20th Century that the olive industry began to grow. Australia had an increasingly
cosmopolitan population including a large portion of Greek and Italian migrant workers
who increased the demand for olive oil production. Despite this, the industry continued for
many years as a boutique industry with small farms of only a few trees in which people
produced their own oil or sold small quantities to others. Olive oil was imported from
Spain, Greece and Italy for many years and by the 1990s the value of the imported olive oil
products was in excess of $100 million dollars per annum.
7.2 Australian consumption
Outside the Mediterranean region, Australia is currently the largest consumer of olive oil
per capita, consuming about 32,000 tonnes of olive oil in 2008. The demand for olive oil
continues to grow, creating a good opportunity for the domestic market. The increased
demand is highlighted by the increase in total imports of olive products in the last five years
(Table 2).
7.3 Australian production
Australia currently has about 10 million olive trees spread across approximately 30,000 ha.
Although the initial plantings of olives in Australia included a large number of cultivars,
today about 90 percent of Australian olive oil is produced from 10 major cultivars including
Arbequina, Barnea, Coratina, Corregiola, Frantoio, Koroneiki, Leccino, Manzanillo,
Pendolino and Picual. These cultivars have been found to be agronomically suitable while at
Olive Oil – Constituents, Quality, Health Properties and Bioconversions
the same time producing a good range of oil types. Barnea, a cultivar from Israel, is a recent
addition to the other predominantly European cultivars but is today the most prolific.
Commercial production increased rapidly from the mid 1990s onwards, designed using
state of the art equipment and methodologies. From an almost non-existent crop prior to
1990, olive oil production in Australia reached 12,000 tonnes in 2008. Due to the modern
technologies used, that production is almost 100% extra virgin olive oil with no facilities or
requirements for solvent extraction and only limited refining capacity for the oil. Only rarely
do harvest conditions produce poor quality fruit which requires refining. These refined oils
would generally be marketed as alternative products. Hence, Australian olive oils in
supermarkets are all extra virgin olive oil. Additionally, around 10 per cent of Australian
groves have organic certification, representing an increase of 60 per cent since 2006
(Australian Olive Association).
Most of Australia’s olives are grown in the east, south and west of the country. Although
South Australia was originally the largest producer, with 39% of total production in 2003,
Victoria has become the leader with 48% of the production in 2009. New South Wales,
Queensland, Western Australia and South Australia share the other half of production. The
main harvest time is May to July although Queensland tends to harvest first due to climate,
although harvest time vary across the states.
Australia’s share of the world’s extra virgin olive oil production has grown from only 0.31
percent in 2006, to 3 per cent of the world market with a 2008 harvest of 12,000 tonnes. By
2014, production is expected to reach 25,000 tonnes.
Production EVOO Table Olives
Year Table
Olives Olive Oil Imports
2001 500 27,680 385 11,545 74
2002 750 28,987 300 12,618 199
2003 1,500 28,447 278 14,483 138
2004 2,000 2,500 32,657 501 13,711 265
2005 2,700 5,000 29,062 1,652 15,143 215
2006 3,200 8,650 34,511 2,988 15,608 230
2007 2,500 9,250 43,404 2,502 16,364 207
2008 2,200 12,000 23,952 4,169 17,542 239
2009 3,000 15,000 31,169 6,960 16,210 366
Table 2. Extra virgin olive oil and table olive production, imports and exports
The majority of olives grown are for oil production. Much of the production is from a few
large producers although there are a large number of small producers spread throughout
the growing regions of Australia. Despite the rapid increase in production, Australians are
continuing to increase their consumption of olive oil and imports have been maintained at
around 20-30,000 tonnes per annum. It would seem however, that there is some import
Cultivation of Olives in Australia 221
replacement with imports of 43,000 tonnes in 2007 being reduced to around 31,000 tonnes
in 2009.
Fig. 3. a. Harvesting at night at Boundary Bend and b. aerial photograph of olive harvesting
at Boundary Bend (photo courtesy of Boundary Bend)
7.4 Australian imports / exports of extra virgin olive oil
Australia imports in excess of 31,000 tonnes of olive oil per annum. Despite that, an
increasing percentage of olive oil is being exported. In 2004, 501 tonnes, or 20 per cent of
Australian production was exported while in 2009, 6,959 tonnes, or around 46 per cent, was
destined for the export market, an average annual increase of 85 per cent. The value of
exports in 2009 was $37.8m (Source ABS).
The top five countries buying Australian extra virgin olive oil have been the United States,
England, China, Singapore and Japan. The Australian customers are changing over time,
with the United States and Italy now being major destinations of Australian olive oils.
Exports to China are also increasing albeit from a very low base.
The export figures from Table 2 indicate that there is a demand and an opportunity for
Australian olive producers to continue to sell olive oil overseas. Despite that, a significant
level of import replacement is a long term goal for the Australian olive industry and is on
track to being achieved. The amount of Australian produced olive oil that is consumed
domestically is now one quarter of the sum total of olive oil that is imported. The increased
Olive Oil – Constituents, Quality, Health Properties and Bioconversions
percentage of Australian olive oil that is being consumed domestically has occurred in the
context of fairly static import volumes over the last 5 years. Further increases in market
share for Australian extra virgin olive oil in the domestic market will require further
investment in consumer education.
7.5 Table olives
Data about table olive production in Australia is less well known than for olive oil.
Although olives for oil production have been increasing rapidly, table olives have not had
such success with production figures increasing from 2000 tonnes in 2004 to only 3000
tonnes in 2009 (Table 2). Although there are many boutique operations, a few operations
have the capacity to process hundreds of tonnes of olives. Table olives are appearing more
on domestic and export markets but large-scale production is still limited by the costs of
harvesting. Despite the limited increase in production of table olives, the demand for them
continues to increase. Imports of table olives have increased from 12,000 tonnes in 2001 to
16,000 tonnes in 2009 (Table 2.). Exports of Australian table olives have remained steady over
the past few years, with around $800,000 worth of table olives having been exported in 2007.
By far the greater amount of research on olives has been directed toward the production of
high quality olive oil. However, in addition to this research on oil and applications in
Australia, some work has also been carried out on table olives (Kailis & Harris, 2004). The
Australian table olive industry and trade currently has no nationally accepted guidelines for
ensuring the quality and safety of processed table olives and the Kailis report was prepared
for olive growers and processors from both national and international viewpoints.
Percentage of production for Australian States
Year Olive Oil
(tonnes) NSW Qld SA Vic Tas WA
2001 500 - - - - - -
2002 750 - - - - - -
2003 1,500 11 12 39 28 1 9
2004 2,500 12 8 16 47 1 16
2005 5,000 12.1 5 16.2 40.1 0.4 26.2
2006 8,650 8.3 4 18.2 53.9 0.2 15.4
2007 9,250 8 4.1 14.6 49.2 0.2 23.9
2008 12,000 7.7 4.1 19.5 53 0.2 15.5
2009 15,000 9.0 4.3 14.5 48.0 0.2 24
Table 3. Percentage of olive oil produced per State.
8. Quality
Australian olive oil quality is generally of high quality using modern technology for
growing, harvesting, processing and packaging. The majority of the crop is mechanically
harvested and transported to processing facilities within a few hours. Everything from the
Cultivation of Olives in Australia 223
machines used to harvest the fruit through to the temperature controlled stainless steel
storage vessels are built on new technology. Oil extractors are generally centrifugal
machines which are kept hygienically clean and housed in temperature controlled facilities.
The oil produced is almost entirely extra virgin olive oil and is ensured through the
Australian Olive Association’s “Code of Practice”. The code requires olive growers to have
their oil tested to ensure EVOO quality at the time of bottling. It also requires that the oil
remains within specifications throughout the oils “best before” date to provide the
consumer with confidence that the product meets the label qualifications. Only fruit that
may have been damaged through frost, insect or disease generally fails EVOO quality. In
these cases the oil is refined and redirected toward alternative uses.
Australia maintains two IOC accredited laboratories and sensory panels which advise the
industry on oil quality. There is a continuous educational program through workshops and
conferences to inform producers and consumers to help them understand defects and
attributes in olive oil. The AOA presents several industry awards to olive oil producers at
the annual AOA Expo. In addition, many regional growers groups have their own olive
competitions judged by trained sensory personnel. All of the olive competitions demand
that the oil passes basic chemical requirements.
8.1 Fatty acids
For commercial samples, the majority of oil analysis is carried out by the two Australian
IOC accredited laboratories. This allows the laboratories to keep accurate records of the
quality of oil being produced in Australia from year to year.
Free fatty acid value (FFA) of olive oil is a general indicator of how sound the olive fruit was
at harvest and how carefully it was processed into oil. Table 4 shows a typical range for free
fatty acids (FFA) and peroxide value (PV). The range shows that the majority of oils are well
within acceptable limits with the median value of 0.18 FFA and 8 mEq oxygen/kg.
Occasionally, due to fruit damage or climatic factors, oils may be outside of acceptable
standards. However, less than 3.3% of FFA samples and 2.2% of PV samples failed to meet
the IOC limits in 2006.
2006 Free Fatty Acid Peroxide Value
Minimum 0.05 0
Maximum 3.48 48
Average 0.26 9
Median 0.18 8
No of samples 585 501
Table 4. Typical range of free fatty acids and peroxide value in Australian olive oil based on
commercial samples in 2006.
The quality of Australian extra virgin olive oil has improved over the last decade. A
summary of the FFA’s of olive oils submitted to the Australian National EVOO Competition
since 1997 (Table 5) shows how oil quality has improved. Between 1997 and 2002, only 34%
Olive Oil – Constituents, Quality, Health Properties and Bioconversions
of the oils were less than 0.19% free fatty acids. In the following six years, from 2003 to 2009,
62% were less than 0.19% FFA.
1997-2002 2003-2009
<0.19 34% <0.19 62%
0.20-0.29 33% 0.20-0.29 26%
0.30-0.39 14% 0.30-0.3 8%
>0.40 19% >0.40 4%
Table 5. Average free fatty acid levels of Australian olive over two periods (AOA)
The variable Australian climate and differences in temperature during fruit development
has a strong influence on fatty acid profiles (FAP) as shown for oil analyses carried out in
2006 (Table 6). The profile of the fatty acids covers the full IOC range for acceptable limits
but exceeds that range in several instances. Although the range is not indicative of nutritive
value, the issues of compliance to international standards are significant.
Sample C16:0 C16:1 C17:0 C17:1 C18:0 C18:1 C18:2 C18:3 C20:0 C20:1 C22:0
limits 7.5- 20.0 0.3-3.5 0.3 0.3 0.5 - 5.0 55.0 - 83.0 3.5 - 21.0 1.0 0.6 0.4 0.2
Average 12.3 0.9 0.1 0.1 2.1 74.1 8.9 0.7 0.3 0.3 0.1
Min 7.4 0.4 0.0 0.0 1.1 55.7 2.7 0.4 0.2 0.1 0.0
Max 18.3 1.9 0.4 0.6 4.0 84.9 23.4 1.5 0.5 0.5 0.2
Table 6. Average, minimum and maximum limits for FAP of Australian olive oil in 2006
The range of fatty acids is further demonstrated with the analysis of samples from New
Zealand, a cooler climate to that of the Australian olive producing areas. The FAP of 56
randomly selected samples in 2006 (Table 7) show that the oleic acid level often (23%)
exceeds the IOC values which suggest these oils are nutritionally superior to those with high
levels of saturated fat. However, these oils would officially fail the IOC standard. Many
samples are lower (17%) than the IOC standard for palmitic (saturated) acid.
Fatty Acids C16:0 C16:1 C17:0 C17:1 C18:0 C18:1 C18:2 C18:3 C20:0 C20:1 C22:0
Max 12.4 0.9 0.06 0.11 2.59
85.5 7.6 0.9 0.4 0.4 0.2
Min 6.4 0.3 0.03 0.06 1.12 78.2 3.0 0.5 0.2 0.2 0.1
Table 7. Fatty acid profile of 56 randomly selected New Zealand oils from 2006.
8.2 Phytosterols
There is also a significant range in the phytosterol content and profile in Australian olive oil
(Table 8). In particular, the level of campesterol often exceeds 4.0%, generally due to the
production level of cv Barnea which is higher in campesterol than other cultivars. Due to the
Cultivation of Olives in Australia 225
suitability of this cultivar to the Australian climate and its high production rate, this cultivar
will continue to be a significant portion of the Australian crop. As for other parameters,
these components may exceed the international limits.
Sterols (%)
D-7- Avenasterol
D-7- Stigmastenol
Average 0.08 0.00 0.09 3.61 0.16 0.63 0.50 0.19 0.13
Min. 0.03 0.00 0.02 2.27 0.10 0.34 0.22 0.00 0.00
Max. 0.16 0.02 0.48 4.89 0.25 1.41 1.00 0.52 0.59
Median 0.07 0.00 0.07 3.49 0.15 0.56 0.47 0.19 0.06
D-5- Avenasterol
β sitosterol
Total Sterols
Average 85.08 7.34 0.01 0.58 0.93 0.68 94.62 1.11 1537.8
Min. 79.45 5.21 0.00 0.20 0.28 0.21 93.83 0.64 1131.7
Max. 88.24 13.66 0.13 0.93 2.51 1.27 96.38 3.09 2153.8
Median 85.75 6.81 0.00 0.60 0.48 0.58 94.56 1.06 1520.9
Table 8. Phytosterols profile in Australian olive oil showing the range and the average and
median values for each component.
9. Research
9.1 Funding
A new agricultural industry requires significant research and development support to
optimise the industry. Such was the case with the awakening of the olive industry in
Australia. It created a need for Australian research scientists to develop an understanding of
the agronomy and the chemistry of the crop, essential for producing the highest yield with
the best quality. The research effort has been supported strongly by the Australian Olive
Association and financial support from some of the larger producers. Much of the financial
support has come from the Federal Governments “Rural Industries Research and
Olive Oil – Constituents, Quality, Health Properties and Bioconversions
Development Council” ( which has consistently supported projects the
olive industry considered to be of significant value.
Although most Australian agricultural industries pay a levy to the Federal Government to
support research, olives have always been considered a new crop and have been exempt
from a levy. However, in 2011, through support from the Australian Olive Association, the
industry has agreed to contribute to a crop levy. This guarantees ongoing funding for the
research and development of this industry in the future.
9.2 Cultivar selection
Determining which cultivars to grow was an early requirement for growers. At the early
stages of development one of Australia’s best resources was the historic olive orchard at
Wagga Wagga. This orchard, with over 50 cultivars and trees which, in some cases, were
over 100 years old, provided an ideal resource for study. Such was one of the first research
projects funded by RIRDC (Ayton et al., 2001) in which oil content, oil quality and initial
attempts to identify cultivars by DNA were carried out. The range of trees, some of which
were grafting experiments and others with varying levels of irrigation, appeared to be an
ideal study. Although the trees were producing reasonable crops due to poor maintenance
for such a long period, and the variable conditions under which each of the trees were
grown, the use of the data was limited.
There remained considerable confusion about cultivars being grown in Australia and if they
were true to type. After many years, maps of the grove had been altered and many trees
removed. Using RAPD DNA methods to discriminate between the cultivars (Mailer & May,
2002), dendrograms were constructed showing the relationship of the cultivars to each
other. Although some trees were identified, it was not possible to obtain reference standards
for many of the cultivars and they remained unknown. Errors in this labelling on the map
became evident as shown by the dendrogram of trees labelled as cv Manzanillo in Fig 4. The
comparison of trees, reportedly to be the same cultivar, was clearly different, based on DNA
patterns and seed morphology.
There was little data on the performance of any olive variety for optimal yields and quality
under Australian conditions and the industry has relied on information from the Northern
hemisphere, particularly from Mediterranean sources. Performance characteristics of
cultivars are the basis on which a selection is made for a particular use or physical situation.
The National Olive Variety Assessment (NOVA) project was established to help resolve the
confusion in olive variety identity and to evaluate the performance, in different climatic
regions of Australia, of the majority of known commercial olive varieties. (Sweeney, 2005).
The establishment of a national varietal grove at Roseworthy provided an opportunity for
growers to evaluate different cultivars, grown at that site.
At the same time studies were being undertaken on wild olive trees which had become
established in the Adelaide Hills to attempt to identify feral olives which may be better
adapted to the Australian conditions (Sedgley, 2000). Despite these investigations, the
Australian industry has been established on common European cultivars and some more
recently introduced including cv Barnea from Israel.
Cultivation of Olives in Australia 227
Fig. 4. Dendrogram created with 10 RAPD primers illustrating differences in seed
morphology of 11 trees identified by the historic map as cv Manzanillo (Mailer
9.3 Environment
Perhaps the main issue for Australian oils was the very variable environmental conditions
under which the crop was being grown. Oil quantity and quality rely heavily on crop
management, moisture availability, harvest timing, processing methodology and storage. As
a result of these differences Australian oils showed a wide range in the fatty acid profiles
(Mailer, 2005b). The diversity in other quality characteristics and sensory analysis were also
In the initial stages of the development of this industry, there was little understanding of the
intricacies of these crop management practices and the resultant crop yield, chemical quality
and sensory attributes such as taste, colour and odour. For these reasons, several studies
have been undertaken to look at the relationship between oil quality and harvest timing,
irrigation treatments, yield and sensory characteristics (Mailer 2007).
As a result of the low rainfall and unpredictable nature of the Australian environment,
almost all Australian olive groves are irrigated. Irrigation provides more predictable yields
and harvest timing unlike dryland groves. Due to the importance of irrigation, research has
focussed on water requirements, particularly in the stages from planting to commercial
harvesting (De Barro, 2005). This research has been aimed at increasing the understanding
of olive water use and requirements in the period from planting to early fruit bearing. As
most Australian olive groves are irrigated several studies have focussed on variation in
maturity, yield, oil quality and sensory attributes under variable moisture availability
(Ayton et al., 2007) and with different harvest times.
Environmental effects on oil production have created unexpected issues for Australian
producers. The variation in quality and sensory has created a new spectrum of oils with
unique qualities and sometimes more variable attributes than has been produced in
Mediterranean climates. This sometimes results in the oil being outside the limited range of
existing international standards (Mailer, 2007).
Olive Oil – Constituents, Quality, Health Properties and Bioconversions
9.4 Harvesting and processing
Along with the determination of the best cultivars, the methods of harvesting and
processing have been evaluated. Many types of harvesters and extractors, generally from
European manufacturers, were being used throughout the industry. Hand harvesting and
many types of vibrating rakes, tree shakers and accessories were unsuitable for large scale
production. Larger producers investigated straddle harvesters (Fig. 3) which underwent
several modifications to make them suitable. These are used widely today.
Processing also went through stages. Some producers tried mechanical mat presses or stone
mills (Mailer & Ayton, 2004) in the early stages but these were never used for large scale
production The majority of processors have installed modern two or three phase centrifugal
extraction mills.
Fig. 5. One of the early harvesting methods adopted in an Australian olive grove.
9.5 Quality analysis
As the industry developed, a need for quality evaluation increased. Using the resources of
the International Olive Oil Council, Australian laboratories were able to set up methods to
determine oil quality. Many of the existing methods were time consuming, reasonably
difficult to carry out and expensive. This prompted the investigation of more rapid methods
such as the near infra red spectrometry (Mailer, 2004), a rapid screening analytical tool
whilst more intensive, wet chemistry methods were maintained as checks where necessary.
Minor compounds in olive oil were recognised as the basis of the sensory attributes,
nutritional value and stability, or antioxidant capacity, of the oil. Additionally, minor
compounds are used to ensure authenticity in Australian research, particularly the sterol
profile. As Australian oil has a wide spectrum for each of the sterol components, which may lie
outside the limits of the IOC standards, this has been an important focus for Australian
scientists (Guillaume et al., 2010). Environmental effects and irrigation on polyphenols both
showed a significant effect (Mailer et al 2007). The influence of frost on these compounds and
the resulting changes in sensory and chemical characteristics has also been investigated
(Guillaume et al., 2009). Frost is one of the most important weather related hazards for the
Australian olive industry and has caused significant economic losses during the past decade.
Its impact on oil quality has been significant in 2006 with more than 20 per cent of Australian
Cultivation of Olives in Australia 229
oil of that year being affected to some degree. Early frosts will normally affect the fruit leading
to significant changes in the chemical and organoleptic characteristics of the oils.
9.6 Shelf life
Although oil may be acceptable when it is processed, maintaining the quality after
processing became a major consideration. Two studies carried out in 2008 by the
Australian Olive Association on supermarket oils (AOA Report – unpublished) included
22 oils initially and later, a further 33 oils of random brands. The reports revealed that
many oils would not pass IOC tests most likely because of poor storage or old age,
although some oils were clearly adulterated. The AOA and RIRDC have funded long term
storage studies under extremes of temperature, light and oxygen exposure to determine
potential shelf life and develop an understanding of methods used to advise marketing on
potential shelf life.
Shelf life depends heavily on the type of material the oil is stored in. Although most experts
would recommend the use of glass or stainless steel, often oil is stored temporarily in plastic
bottles or collapsible bags. Studies on the effects of the different types of containers used for
transport and sometimes for long term storage have been published (Mailer & Graham,
2009). The study reinforces that the best storage conditions for olive oil is in opaque,
impervious and inert containers, stored at cool temperatures. Metallised flexible bags used
for short term transport may provide reasonable protection. Storage in clear plastic,
particularly in the light and at elevated temperatures, is unacceptable and results in loss of
extra-virgin olive oil quality within a short period. Re-use of these containers is highly
undesirable and would cause more rapid degradation.
9.7 Pest and disease
Australia has been free of many cosmopolitan olive pests due to its isolation but the rapid
expansion of the olive industry in all mainland states has led to increased problems with
pests and diseases. The control of these problems became a focus for all growers. A report
on sustainable Pest & Disease Management in Australia Olive Production (Spooner-Hart,
2005) describes sustainable management, monitoring pest and beneficial species in groves
and identified a number of previously unreported pests and diseases. Further publications
have included a field guide to olive pests, diseases and disorders in Australia (Spooner-Hart
et al., 2007) designed as a quick reference to take into the grove and use to identify pests and
diseases and the damage they cause.
9.8 Waste management
Dealing with by-products of olive oil processing is another important issue in modern
agriculture. A study on recycling of solid waste from the olive oil extraction process (Tan &
Markham, 2008) and a subsequent report outlines methods for developing an
environmentally sustainable system to manage solid waste from the 2- and 3-phase olive oil
mill extraction processes. The expanding Australian olive industry over recent years, with
significant increase in fruit production, has resulted in vast quantities of solid and liquid
wastes generated to the detriment of the environment. The industry is been faced with the
Olive Oil – Constituents, Quality, Health Properties and Bioconversions
challenge to manage these wastes in order to achieve sustainable production under a clean
environment. The research work provided the industry with a tool to recycle processed oil
mill waste to improve the health of the crop and the status of the soil.
9.9 Reviews
The revival and development of the olive industry stimulated wide areas of research over a
relatively short period. The quest for information has been intense. This has led to the
publication of several reviews being carried out, particularly regarding the potential for
olive production in Australia. These include studies by McEvoy et al. (1999) in which the
market for the development of an olive industry in Australia was examined based on
analysis of: trends in international production and trade; consumer segments and product
characteristics; whether Australia could compete with imported olive products.
Another review contains detailed steps required to establish an olive grove in Australia and
is a comprehensive survey of the Australian Industry (Meyers Strategy Group, 2010). It was
developed as a method of establishing how Australia could compete in a rapidly growing
olive industry worldwide.
10. References
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developing olives in a selection of Australian cultivars. Australian Journal of
Experimental Agricultural. 41: 815-821
Ayton, J., R. J. Mailer, A. Haigh, D. Tronson, D. Conlan. 2007. Quality and oxidative stability
of Australian olive oil according to harvest date and irrigation. Journal of Food Lipids
De Barro J. 2005. From Planting to Harvest - A Study of Water Requirements of Olives, from
planting to first commercial harvest. Report No. 05-039, 1 Jun 2005. ISBN: 1-74151-
138-0. Web:
Frankel, E.N., Mailer, R.J., Wang, S. C., Shoemaker, C.F., Guinard, J-X., Flynn, D., and
Sturzenberger, N. 2011. Evaluation of extra virgin olive oil sold in California. UC
Davis Olive Centre.
Guillaume, C., Ravetti, L. And Gwyn, S. 2009 Characterisation of Phenolic Compounds in
Oils Produced from Frosted Olives. Report 09-058. 5 May ISBN: 1-74151-860-1.
Guillaume, C; Ravetti, L and Johnson J. Sterols in Australian olive oils: The effects of
technological and biological factors. RIRDC Report: 14 Oct 2010. ISBN: 978-1-74254-
Hobman F. 1995. An economic study into irrigated olive growing and oil processing in
Southern Australia. A report for RIRDC. Research Paper No 95/5.
Kailis, S. G. And Harris, D. 2004. Establish protocols and guidelines for table olive
processing in Australia. Report No. 04-136. 1 Oct 2004. ISBN: 1-74151-044-9. Web:
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Mailer, R.J. 2004. Rapid evaluation of olive oil by NIR reflectance spectroscopy. Journal
American Oil Chemists’ Society. 81(9):823-827
Mailer, R.J. 2005a. Establishment of an olive oil sensory panel. A Report prepared for
Horticulture Australia Limited. Report FR02054.
Mailer, R.J., 2005b. Variation in oil quality and fatty acid composition in Australian olive oil.
Australian Journal of Experimental Agriculture. 45:115-119)
Mailer, R.J. 2007. The natural chemistry of Australian extra virgin olive oil. RIRDC
Publication No. 06/132, Project DAN239A.
Mailer, R.J., Ayton, J. 2004. Comparison of olive oil (Olea europaea) quality extracted by
stone mill and hammermill. New Zealand Journal of Horticultural Science.
Mailer, R.J. Ayton, J. and Conlan, D. 2002. Comparison and evaluation of the quality of
thirty eight commercial Australian and New Zealand olive oils. Advances in
Horticultural Sciences. (16)3-4: 259-256).
Mailer R.J., Ayton, J. and Conlan D. 2007. Influence of harvest timing on olive (Olea
europaea) oil accumulation and fruit characteristics in Australian conditions
Journal of Food, Agriculture & Environment. Vol 5. (3 & 4): 58-63).
Mailer, R. J., and Graham, K. 2009. Effect of storage containers on olive oil quality. Report
No. 09-160. 26 Oct 2009. ISBN: 1-74151-957-8. Web:
Mailer, R.J. and May, C.E. 2002. Variability and interrelationships of olive trees and cultivars
using RAPD analysis. Advances in Horticultural Sciences. (16)3-4: 192-197
McEvoy, D., Gomez, E., McCarrol, A and Sevil, J. 1999. The olive industry: a marketing
study report. No. 99-086, 1 Jan 1999. ISBN: 0-642-57993-8. Web:
Meyers Strategy Group Pty. Ltd. 2001. Regional Australia olive oil processing plants. RIRDC
Report No. 00-187. 1 Feb 2001. ISBN: 0-642-58218-1. Web:
Nair (Tan), N.G. and Markham, J. 2008. Recycling solid waste from the olive oil extraction
process. Report Code: 08-165, 28 Oct 2008. ISBN: 1-74151-754-0. Web:
Rowe, I and Parsons, L. 2005 Ten years of the AOA. The Olive Press - Winter Edition.
Australian Olive Association newsletter. pp 9-10.
Sedgley, M. 2000. Wild olive selection for quality oil production. A report for the Rural
Industries Research and Development Corporation. RIRDC Publication No 00/116
RDC Project No UA-41A.
Spennemann, D H R. 1997. The spread of Olives (Olea sp.) on Waggas Wagga Campus.
I. Biology and History. Charles Sturt University. Johnstone Centre Report No.
Spennemann, DHR. 2000. Centenary of Olive Processing at Charles Sturt University. Charles
Sturt University, Faculty of Science and Agriculture. ISBN 1 86467 070 3
Spooner-Hart, R. 2005. Sustainable Pest & Disease Management in Australia Olive
Production. Report No. 05-080, 1 Jun 2005. ISBN: 1-74151-143-7.
Olive Oil – Constituents, Quality, Health Properties and Bioconversions
Spooner-Hart, R., Tesoriero, L. and Hall B. 2007. Field guide to olive pests, diseases and
disorders in Australia. Report No. 07-153, 1 Oct 2007. ISBN: 1-74151-549-1.
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Publication No 05/155. Project No. SAR-47A. Rural Industries Research and
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... Olive production has expanded rapidly in recent years due to the adaptation of intensive and super-high density planting systems in new commercial orchards. As a result of the low rainfall and the unpredictable nature of Australian olive crop environments, almost all Australian olive orchards are irrigated (Mailer, 2012). This is also the case in Argentina because annual rainfall is most often between 100 and 400 mm . ...
Full-text available
Olive (Olea europaea L.) is a crop well adapted to the environmental conditions prevailing in the Mediterranean Basin. Nevertheless, the increasing international demand for olive oil and table olives in the last two decades has led to expansion of olive cultivation in some countries of the southern hemisphere, notably in Argentina, Chile, Perú and Australia. While the percentage of world production represented by these countries is still low, many of the new production regions do not have typical Mediterranean climates, and some are located at subtropical latitudes where there is relatively little information about crop function. Thus, the primary objective of this review was to assess recently published scientific literature on olive cultivation in these new crop environments. The review focuses on three main aspects: (a) chilling requirements for flowering, (b) water requirements and irrigation management, and (c) environmental effects on fruit oil concentration and quality. In many arid and semiarid regions of South America, temperatures are high and rainfall is low in the winter and early spring months compared to conditions in much of the Mediterranean Basin. High temperatures have often been found to have detrimental effects on olive flowering in many olive cultivars that have been introduced to South America, and a better understanding of chilling requirements is needed. Lack of rainfall in the winter and spring also has resulted in an urgent need to evaluate water requirements from the flower differentiation period in the winter to early fruit bearing. Additionally, in some olive growing areas of South America and Australia, high early season temperatures affect the timing of phenological events such that the onset of oil synthesis occurs sooner than in the Mediterranean Basin with most oil accumulation taking place in the summer when temperatures are very high. Increasing mean daily temperatures have been demonstrated to decrease fruit oil concentration (%) and negatively affect some aspects of oil quality based on both correlative field studies and manipulative experiments. From a practical standpoint, current findings could be used as approximate tools to determine whether the temperature conditions in a proposed new growing region are appropriate for achieving sustainable oil productivity and quality.
Full-text available
With the rapid expansion of the Australian olive industry during the past decade, plantings have been made in many parts of Australia including both temperate and sub-tropical regions, where summer-dominant rainfall may present production problems. Australia appears to be free of many cosmopolitan olive pests and diseases such as olive moth (Prays oleae), olive fly (Bactrocera oleae) and olive knot (Pseudomonas savastanoi), although some species such as black scale (Saissetia oleae) and peacock spot (Spilocea oleaginea) are widely distributed. Australia also has several native pests of cultivated olive, including olive lace bug, Froggattia olivinia and Queensland fruit fly, Bactrocera tryoni. The industry has identified sustainable pest and disease management as a key priority, and a national project has been funded by the Australian Government through the Rural Industries Research and Development Corporation.
Full-text available
The Australian olive oil industry is expanding rapidly, with production set to reach 30,000 tonnes by 2010. Harvest timing plays a key role in the yield and quality of olive oil. In this study, fruit from three olive cultivars, Corregiolla, Mission and Paragon growing in the south western region of New South Wales, Australia, were harvested at six different times during the season, over three years. Physical measurements of the fruit, such as maturity index, moisture content, oil content (solvent extracted and mechanical) and fruit weight were determined. Most parameters measured showed a significant year effect. Harvest timing effects were also apparent. Generally, the moisture content of the fruit decreased as the fruit matured. Oil content by solvent extraction showed a rapid increase during the first part of fruit maturation, followed by a slower increase later in the season. Fresh fruit weight increased with maturity for most cultivars. Information about individual cultivars is important for growers when harvesting in order to gain maximum yield.
Full-text available
This study compared two olive oil extraction processes used in New Zealand to assess the influence of processing on oil quality. The extraction systems included an Enorossi stonemill and an Oliomio 50 hammermill, malaxing basin, and centrifuge. Olives (Olea europaea) from individual harvests were found to show significantly higher polyphenol and chlorophyll content from the hammermill process. Slightly higher free fatty acids resulted from the hammermill. Fatty acid profiles did not show significant differences between the methods of extraction. Storage over 17 months resulted in increased peroxide values for both oils but no change in chlorophyll, free fatty acids, or polyphenols.
Olive oil consumption in Australia has increased dramatically in recent years with the volume of imports increasing from 13,500 tonnes in 1990/91 to 30,000 tonnes in 2000/01. More than 20,000 hectares of olives have been established in Australia and New Zealand since the mid 1990s and some of these are now beginning to bear commercial yields of fruit for oil production from a diverse range of environments. This study has been carried out to determine the range in quality of Australian and New Zealand olive oils and if the quality meets the International Olive Oil Council standards. The results illustrate that the oils selected cover a wide range for each of the quality characteristics tested. Most of the oils were within the IOOC standards for extra virgin olive oil. The fatty acid profiles showed a considerable range with palmitic acid (saturated) levels from 9 to 16% and oleic acid (monounsaturated) from 57 to 84%. Peroxide values were all below 20 meq O2/kg although some were higher than 15 meq O2/kg. Free fatty acids were also generally less than 1.0%. Chlorophyll, polyphenol content, UV absorption and induction time were also tested. These results indicate that Australian processing and storage methods, and olive oil quality, are of a high standard.
Random amplified polymorphic DNA sequence (RAPDs) analysis has been used to characterize two historic olivetums in Wagga Wagga and Yanco in southern New South Wales. We have checked the authenticity of some of the cultivars against international standards and have used the collection as a whole to determine the degree of genetic heterogeneity within and between cultivars. Using six selected oligonucleotide primers, we analysed DNA from 92 olive trees of the Wagga Wagga orchard (comprised of 46 named cultivars, 4 selections, and 4 trees of unknown or dubious origin), and from 35 trees of the Yanco orchard (comprised of 4 cultivars). The level of heterogeneity that was found suggests that many, if not all, cultivars are composed of varietal populations with often a considerable genetic overlap between cultivars.
Sterols are important lipids related to the quality of the oil and broadly used for checking its genuineness. Recent analyses have identified that some Australian olive oils would not meet international standards for total content of sterols or for certain individual components. Several research works would indicate that there are some significant correlations between cultural and processing practices and sterols content and composition. In this work we analysed the horticultural and processing practices that may have an impact on the sterol content and profile of the most important Australian cultivars. The information generated with this project does not only aim to solve a legislation problem but also to maximise the nutritional and health value of the Australian olive oils. The evaluation was undertaken in three different cultivars and the horticultural and processing practices evaluated were: irrigation, fruit size, maturity, malaxing time, malaxing temperature and delays between harvest and process. The total content of sterols and their composition in olive oil is strongly influenced by genetic factors and year. Processing practices particularly affect triterpene dialcohols and stigmasterol while horticultural practices and fruit characteristics tend to affect more significantly other sterols such as β-sitosterol, sitostanol, δ5-avenasterol and δ7-avenasterol.
This paper reports on an observational study of the oil and moisture content, and fatty acid profile, of olives (Olea europaea) for 15 tree groupings with groups consisting of trees with similar DNA patterns. Observations were taken at 2 sites (Wagga Wagga and Yanco) in south-western New South Wales, over 2 seasons. These sites represent the largest gene pool of developed olive trees in Australia. Differences in oil and moisture content were identified at both the Wagga Wagga and Yanco sites. At the former site, group 12 (˜cv. Tarascoa) had the highest oil content at full colour development in both 1998 and 1999 (50.1 and 45.5% dry weight, respectively) while at Yanco, group 15 (˜cv. Verdale) had the highest oil content in both years with 51.6 and 45.3%, respectively. The fatty acid profile was shown to be highly dependent upon tree group (i.e. cultivar), and with further study may be used as a method for discriminating among cultivars. The pattern of development of oil, moisture and fatty acids (palmitic, palmitoleic, stearic, oleic, linoleic and linolenic acids) is also detailed for 4 trees in the Wagga Wagga grove over the ripening season in 1998 and 1999. For these trees, oil content (dry weight basis) increased rapidly in the first 15 weeks (January–April) while moisture declined except for a small increase at around 10 weeks (mid-March). Fatty acid development showed similar trends between the trees over the length of the study.
There is little information on the fatty acid composition or other quality aspects of Australian olive oil. In future years, it is predicted that domestic supply will outstrip demand. The industry is therefore focussed on export quality oil that meets international standards. Australia has a very variable environment that has been shown to contribute to a wide range in oil quality, both chemically and organoleptically. This paper summarises the results of the chemical analyses of 822 Australian olive oils carried out at the Wagga Wagga Agricultural Institute over 2002 and 2003. The analyses are compared with IOOC standards for extra virgin olive oil and show that Australia olive oils are generally within these standards. Peroxide values were between 1.9 and 27.2 meq/kg oil with only 10 exceeding 20 meq/kg. Free fatty acids were between 0.05 and 2.16 although they were generally less than the accepted limit of 0.8% with only 28 exceeding that level. Polyphenol content (38-1352 g/kg) and induction time (1.4-23.6 h) showed wide variation although these have no IOOC recommended standard. The fatty acid profiles also showed a considerable range with palmitic acid (saturated) levels from 7.8 to 18.9% and oleic acid (monounsaturated) from 58.5 to 83.2%. Linoleic acid ranged from 2.8 to 21.1%. Of particular concern was the range for linolenic acid from 0.42 to 1.91%. For this component, 29 oils exceeded the maximum linolenic acid level of less than or equal to1.0% recommended by the IOOC. This data provides evidence of the variation in oil quality and fatty acid profiles resulting from Australia's diverse environments and cultivars.