Issue 6

Muntari - Much More than a Ground Cover!

Brian King, Muntari Wild Food Plants of Australia

Common names:

Muntari, Muntaberry, Munthari, Muntries

Botanical name: Kunzea pomifera muntari

Family: MYRTACEAE

This plant is well known to people in southern areas of South Australia and western coastal districts of Victoria but perhaps not so to those on the eastern sea board. It was brought into cultivation some years for use as a flowering ground cover.

Index: 6
From the Ed
Letters
Introducing diploglottis
Aboriginal Food
Temperate species
Tourists and Bushfoods
Muntari
Essential Oil Distillation
Profile: Brian King
Bushfood Plants for Colder Climates
3 Bucket Garden
Profile: Jenny Allen
Bush Jams - John Wrench
Recipes
Company profiles
Book reviews
Resources
Who's buying and selling

The natural habitats of this temperate zone plant are coastal sandhills and mallees.

It is a long lived prostrate (trailing) shrub or ground cover which can spread to around 2-3 metres, sometimes more. It's leaves are dark green and glossy with an ovate shape and recurved tip. This simply means the leaf shape is oval and that the edges of the leaf near the tip are bent slightly downwards, as when someone pokes out their tongue.

The stems are woody and many branched and in good conditions may root at the nodes (points on branches from which new leaves grow). This helps the plant to spread. White or cream coloured, very showy flowers are produced abundantly in terminal clusters (groups at the end of branches) during late spring and early summer resembling blossom of the Eucalyptus sp. to which the Kunzea is related.

Small round green berries 10 - 12mm in diameter and resembling miniature apples are produced following the flowering period. This is usually around mid to late summer (Dec - Feb) in southern areas. The fruit develop a red / purple colouring when ripe and have a flavour similar to apple but without the acidity. They may be eaten fresh or used in jams, chutneys and sauces.

Fruit may be frozen without loosing colour, texture or flavour so this may be the best way to store excess harvest although they can also be dried using conventional dehydration methods.

Propagation of this Kunzea is from seed or cuttings however, seedlings will not usually bear fruit until the second or third year. Plants propagated from cuttings on the other hand, will fruit in the first season if the root structure is advanced enough.

Growing naturally in sandy soils over limestone, it can be appreciated that in cultivation also, the plant requires a well drained alkaline soil in full sun to be at it's best for fruit production. While it may survive in neutral to slightly acid soils and produce plenty of leaf and stem growth, it will be at the expense of flowering and hence fruit.

Although a relatively hardy plant that will tolerate frosts and short dry periods, it will not survive prolonged drought conditions. Water logged soils will definitely kill the plant as the root system is very fibrous and better adapted to sandy soils not swamps! For home gardens a rockery is the perfect place for Kunzea pomifera.

Slow release fertiliser formulated for native plants can be applied twice a year, in early Spring and mid Autumn. Small amounts of blood and bone fertiliser can be applied in late Spring - early Summer to steady the plant through it's fruiting period. Watering should be kept constant but not excessive with deep soakings every 12 - 14 days using a dripper system rather than overhead spraying.

Once the plant reaches a suitable size it can be tip pruned to keep it's shape. Although this can be done anytime of year, our experience has shown late winter to be the best period.

One of the hurdles to be overcome in commercial production is the picking of the fruit. The berries are held in neat little clusters making it easy to grasp them but, because they are so near ground level, hand picking can be a real pain in the back, literally. A number of different ways of circumventing this problem have been tried ranging from training onto trellises through to growing in large diameter PVC pipe stood on it's end.

The main goal is to achieve a comfortable picking height without causing damage to the plant. Another way is to graft the plant onto a suitable rootstock which is grown to the required height. The problem here is to find one or more compatible rootstocks having singular upright growth habits and reliability when grown on a variety of soil types.

We have grafted onto 4 different varieties and will be testing them further under trial conditions over the next 4-5 years to ascertain their qualities and deficiencies.

Whatever way is chosen to grow them, this great little bushfood plant will produce a fruit that is tasty, versatile and well deserving of its place in Australian cuisine.

Essential Oil Distillation -

Dennis Archer, Toona Essential Oils, (O7) 5486 5216

Essential oils - everybody uses them, whether it's eucalyptus oil for cleaning sticky tape off the walls, tea tree for medicinal purposes. a couple of drops of your favourite in a relaxing bath, burning a bug repellent candle at a barbecue, or adding Lemon scented myrtle to a cheesecake.

An essential oil is any class of oil obtained from a plant possessing the smell and other properties of the plant, and volatilising completely when heated.

Whether you live in a flat or have thousand of acres, it is possible to grow the raw material (biomass) needed to produce essential oils. Australia has a large number of native trees and shrubs which are suitable for the production of essential oils, and these compare more than favourably with imported oils.

 

 

Wouldn't it be great to be able to produce our own essential oils from our own trees ? Yes and no. Unless you are planning to produce commercially, it is often cheaper in the long run to buy from retail outlets. However, it can he a lot of fun, albeit time consuming, to produce your own oil from your own plants.

The history of the production of essential oils goes back to at least the Romans, and has continued since, with a variety of methods being used. Briefly, methods that can be used are as below. (More complete information can be obtained in Essential Oils, Kim Fletcher, 1995, Penguin.)

Maceration - steeping the flowers and other plant parts in oil until the oil has absorbed the fragrance of the plant.

Distillation - total immersion of the finely chopped leaves in water, heat to boiling point, essential oil rises to surface and volatilises.

Steam distillation - most common method. Biomass into pot; pass steam through, condense the vapour produced, oil and water to separator, draw off the oil.condensation

 

stillWater and steam distillation: support the biomass on a grid above boiling water, condense the vapour, separate and draw off the oil

 

Enfleurage - a series of sheets of glass, covered with a purified fat, onto which petals are laid, cover with another glass plate with a fat; layer (leave a small air gap) and leave for 24 hours. Remove flowers, replace with fresh material, and continue process. After harvest is finished, the perfumed fat, (pomade) is scraped off and stored in airtight containers. The pomade can be treated with alcohol to extract the natural flower extract. Solvent extraction - wash the biomass (usually flowers) with a solvent such as ethanol, evaporate off the solvent to produce a concrete of oil, resin & colours and other parts of the plant, wash with alcohol to remove all except the essential oil, evaporate to produce the floral absolute.  

Expression - cold press the essential oil from the rinds of citrus fruits, centrifuge to remove solids, cool, remove oil floating on top.express

 

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As mentioned, the most common and cheapest is steam distillation, which is basically a vessel (pot) with a grid just above the base which is loaded with biomass (charge). Steam is passed through the charge to rupture the oil glands of the plant material and carry the steam and oil to the top of the pot. This vapour passes into a condenser which cools and condenses the vapour into the liquid components. The liquids fall into a separator from which the essential oil can be recovered, remembering that essential oils can be both heavier and lighter than water.

 

Each biomass has a different yield, i.e. the volume or weight of essential oil that is produced from the weight of the biomass, and this is expressed in terms of a percentage. For example, some biomass will yield 2mls of oil from 200 grams of biomass, others will yield less than 1ml, while some may produce 4 mls from the same weight of original material.

Yields can be affected by many factors such as the time of year, climatic conditions, plant stress from lack of water or pest infestation, too much or too little nutrient, how much woody matter is included in the distilled material, has the biomass been comminuted (cut or shredded) and the condition of the biomass after harvesting. While some plants require wilting before distillation, the majority should be distilled as soon as possible after harvesting.

When discussing yield and extrapolating to mass production, remember - the yield achieved in a laboratory situation may be more than twice the yield achieved in a commercial distillation.

For home distillation, very small amounts of oil, maybe only a skim on the top of the water, can be produced by adaptation of household equipment.

A lab-type distillation unit will cost about $500 and each distillation will produce only a small amount of oil, maybe up to 4-5m1s, dependent on the raw material.

Apart from the cost, any distillation unit (still) must be registered with the Australian Customs Service. This does not cost anything (at present) but, if not registered, the Customs Service are able to seize the equipment with no compensation, and possible legal action could ensue. As an aside, the term ` still' is only used for production of spiritous liquors and that's another ball game.

The decision to install a commercial distillation unit is dependent on finance. Using second hand equipment, a distillation unit with all the bits and pieces may be set up for as little as $20,000. Alternatively, a system for large scale distillation can cost $350,000 or more.

mobileAnother alternative is to find a distillation unit in the near vicinity (within an hour's travel time), and contract out the distillation.

 

Mobile Still

The last is often used by growers in the early stages of development of their commercial plantation, until there are enough trees and produced oil to warrant the expenditure on their own farm-based unit.

What type of unit? Boiler or steam generated? Solvent extraction? What fuel to power the unit - wood, oil, diesel or gas and electricity requirements? What licences, permits, permissions and registrations are needed to install and run a distillation unit? What size steam production unit? How big, and what type, should the pot (into which the biomass or charge is placed) be? What size and sort of condenser and separator do I need? How much and what sort of water is required for the steam production unit? And for cooling the condenser? What material can I use to build the pot, condenser and separator?

Each of the above is dependent on the individual situation, and is not one that that can be answered in this article, except for the last.

Current regulations are that the material from and including the lid of the pot to the extraction point of the oil, has to be stainless steel or glass. For ease of cleaning, and to reduce contamination, the pot should also be stainless steel. You could use glass, but add a container capable of holding 500 or more kilograms of biomass, a spanner and a moment's inattention, and you have a very expensive accident.

Obviously, there's lots more that could and should be discussed for anyone contemplating doing their own distillation. Those interested should access the local library for further reading, where material can be found, generally in scientific literature.

Tim Denny at PO Box 42, Lilydale, Tasmania, 7268, has written `Field Distillation for Herbaceous Oils', which is available direct from the author.

Most commercial operators are available on a consulting basis to advise prospective essential oil producers, or there are organisations such as the Fraser Coast Essential Oil Association (07) 4121 4588 from which information can be obtained.

It can be fun, it can be frustrating and it can be very humbling, but the times when the air is scented with newly produced Australian native essential oil flowing from the separator makes at all worthwhile.

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