Australian
Table Olive Production Manual
After in depth examination
of international table olive production and discussions with Australian
olive growers and processors the Australian Table Olive Production Manual
focuses on the processing olives in brine, without pre-treatment with sodium
hydroxide, and by salt and heat drying methods.
Quality and safety and HAACP
management of table olive production
Factors identified in relation
to quality and safety and HAACP management of table olive production include
the use of: quality inputs; appropriate equipment; a sanitary environment;
trained operatives; documented methods; product profiles which include
product testing criteria and packing/storage requirements.
Testing
Selected tests were developed
and/or applied to some 300 batches of olives including fresh and processed
olives for the purpose of obtaining base line data and developing product
testing criteria. During processing the aim was to monitor the pH, salt
levels and levels of Enterobacteriacae, Lactic Acid Bacteria, yeasts
and moulds in the brine for the purpose of ensuring effective processing
and reducing the risk of spoilage and harm to consumers. In the case of
chemical, physical and organoleptic assessment, the aim was to provide
base line data for assessing quality and producing data for nutritional
labelling. Microbiological evaluation of processed olives was undertaken
to identify the most suitable testing procedures to ensure safety.
Physical Parameters
• Appearance – colour, size
and shape: maturation state, firmness, flesh to stone ratios
Pressure studies on the fruit
indicated distinct differences in firmness between varieties and maturation
states. Black ripe olives were softer than green ripe olives. Excessively
firm green olives tended to be immature and difficult to process. Processed
olives showed lower pressures than fresh olives. For cracked or bruised
olives where the stone was to be retained, clingstone varieties were more
suitable eg Sevillana, Verdale, whereas for destoning, freestone
varieties such as Manzanilla and Kalamata, were suitable. Large olives
with a high flesh to stone ratio were suitable for destoning and stuffing.
Chemical Parameters
• Olive flesh - moisture,
fat, level of saturated fats, protein, ash, soluble sugars and total carbohydrate.
Fresh olive flesh depending
on the maturation state gave the following range of results – Moisture
(60.9 to 66.86%w/w), fat (14.9 to 24.7%w/w), saturated fats (15.2 to 16.9%w/w
of fat), protein (1.2 to 1.6%w/w), ash (0.6 to 1.0%w/w), total carbohydrate
(8.7 to 10%w/w) and soluble sugars (2.1 to 2.3%).
Similar results were obtained
with processed olives. The soluble sugars were much lower because these
were consumed or lost during processing procedures. Ash levels were higher
because of the added salt content.
• Minerals in olive flesh
– phosphorus, potassium, sodium, calcium, magnesium, sulphur, boron, copper
iron, manganese and zinc.
All olives tested had varying
levels of the above minerals. This screen provided base-line information
on important nutrients as well as the salt concentration of the flesh.
Typical results for two olive styles are given below.
• Kalamata Style (20 samples)
– Phosphorus (0.02+0.002%w/w), Potassium (0.27+0.21%w/w),
Sodium (1.67+0.69%w/w), Calcium (0.04+0.04%w/w), Magnesium
(0.009+0.004%w/w), Sulphur (0.02+0.01%w/w), Boron (11.3+14.52
mg/kg), Copper (2.71+1.68mg/kg), Iron (4.8+1.6mg/kg), Manganese
(1.1+0.6mg/kg) and Zinc (2.3+1.1mg/kg).
• Green Manzanilla Olives
in Brine (17samples) Phosphorus (0.018+0.006%w/w), Potassium (0.21+0.07%w/w),
Sodium (1.81+0.26%w/w), Calcium (0.036+0.009%w/w), Magnesium
(0.007+0.001%w/w), Sulphur (0.015+0.002%w/w), Boron (4.54+1.77
mg/kg), Copper (1.52+0.6 mg/kg), Iron (3.15+0.74 mg/kg),
Manganese (0.65+0.18 mg/kg) and Zinc(2.21+0.66%mg/kg).
• Heavy metal screen of fresh
olives – cadmium and lead
Levels of these elements
were within safe limits for 14 different olive varieties
• Brines – pH, salt and acid
levels
Most commercially available
processed table olives tested had salt and pH levels within IOOC recommendations.
On the experimental side, processing batches of fresh olives in a brine
of 10%w/v of sodium chloride, the levels stabilised to between 5% to 8.8%w/v
sodium chloride and pH values ranging from 4.2 to 6.5. Addition of food
acid (vinegar) would bring the salt and pH parameters within the IOOC recommended
levels.
Microbiological Parameters
The following tests were
undertaken on selected olives and brines. For routine monitoring, levels
of indicator organisms for hygiene, food hazard potential, processing and
spoilage were assessed. All tests were applied to selected processed table
olives and brines.
• Tests on brines during
processing - Enterobacteriacae, Escherecia coli Lactic Acid
Bacteria, yeasts and moulds -
• Tests on olives - Enterobacteriacae,
Lactic Acid Bacteria, Coagulase positive staphylococci, Clostridium
perfringens, Clostridium botulinum, Listeria monocytogenes,
yeasts and moulds.
Of the olives and brines
tested only low levels of organisms were detected.
Organoleptic Assessment
The following Organoleptic
evaluation was undertaken on 210 batches of processed olives - appearance,
colour, colour intensity and homogeneity, aroma, taste, flesh texture,
flesh stone detachment. Attributes were scored on a scale from 1 to 10.
Olives were then graded as – Extra (<1.5), First, (>1.5<3.5),
Second (>3.5<5.5), Mediocre (>5.5<7.5) and Inedible
(>7.5). Findings were Extra (11%), First (32%), Second o29%), Mediocre
(9%).
The main problems found with
processed olives were mixed fruit sizes, skin discolourations, possibly
due to air exposure during processing and olive damage, +bitterness
levels, +salt levels, soft olives and loss of texture.
The Australian Table Olive
Industry
Production of Australian
table olives is small, compared to international markets, however Australia
is a significant importer of table olive products black olives processed
in brine and Spanish style green olives) mainly from Spain, Greece and
to a lesser extent Italy. Table olive imports into Australia are currently
around 12000Tonnes/year. Australian domestic table olive production has
increased markedly from 2000Tonnes/year in 1999/00 to an estimated current
production of 4000Tonnes/year. As few olives are exported from Australia,
olive consumption by Australians is currently of the order of 16000Tonnes/year.
Most of the imported olives come in bulk quantities and are repacked into
consumer size containers either in their original form or marinated with
herbs, spices and other aromatics.
The Australian table olive
industry can be divided into 4 categories – Boutique (up to 5Tonnes/year),
Small (5 to 100Tones/year, Medium (100 to 500Tonnes/year) and Large
scale (greater than 500Tonnes/year). Most Australian table olive enterprises
are boutique or small scale. There are no large-scale operations and there
is only one at the medium scale, which reflects the early stage of the
industry. Most table olive processing is sited in regional Australia often
in close proximity to vineyards and wineries. The latter help induce consumers
to cellar door sales. Other Australian table olives are sold in food outlets.
Most Australian table olive
processors consulted during the study were in favour of using natural fermentation
methods and drying methods (salt or heat drying) for processing table olives
rather than those using alkali treatments. |
