Anise Myrtle (Syzygium anisatum) Oils

Syzygium anisatum (formerly Backhousia anisata and Anetholea anisata) is an Australian rainforest tree with leaves that produce an essential oil (EO) that has the characteristic aroma of aniseed. It is referred to as aniseed myrtle or anise myrtle in the trade and the fresh and dried leaves of this plant are used as a herb in culinary applications. The EO is extracted by steam distillation of the leaves and the major aromatic volatile compound is anethole. The EO has broad spectrum antimicrobial activity but is more effective against bacteria than fungi. Indigenous Australians have used anise myrtle for its medicinal values and in recent times it has been used as a flavoring agent by the food and beverage industry. This chapter covers the use of anise myrtle EO in food and agricultural applications, botanical aspects, and chemical composition.

Lemon Myrtle (Backhousia citriodora) Oils

Lemon myrtle has been traditionally used by indigenous Australians for cooking and healing. More recently, lemon myrtle leaves are used as a dry or fresh herb in food applications and the essential oil (EO) used as a flavoring agent in food and beverages. The leaf of the lemon myrtle (Backhousia citriodora) is steam distilled to produce the EO. Lemon myrtle EO is known for its characteristic lemon flavor and the major chemical component contributing to the aroma is citral. The EO has broad spectrum antimicrobial activity and is very effective against fungi and has increased the potential of using the EO in food preservation and treatment of postharvest diseases in fruits. This chapter covers the use of lemon myrtle EO in food and agriculture applications, general usage, botanical aspects, and chemical composition.

Tasmanian Pepper Leaf (Tasmannia lanceolata) Oils

Tasmannia lanceolata, commonly known as Tasmanian pepper leaf or mountain pepper, is an Australian native plant that produces an essential oil with a characteristic pungent flavor attributed to the sesquiterpene polygodial. The dried and fresh leaves are used in culinary applications. The essential oil is produced by a solvent extraction process, and the resultant concrete is a rich source of the principal pungent molecule polygodial and other volatiles. The Tasmanian pepper leaf extract has broad-spectrum antimicrobial activity and is very effective against fungi, especially yeasts. This demonstrates its potential to be used in the food industry as a natural preservative. Indigenous Australians have used Tasmanian pepper leaves for therapeutic purposes; in recent times, it is been used as a flavoring agent and enhancer of pungency in food products. This chapter covers the use of Tasmanian pepper leaf essential oil in food applications, its botanical aspects, and its chemical composition.

An investigation of environmental conditions experienced during the life of high-value wood components and products

Australian forest industries have a long history of export trade of a wide range of products from woodchips (for paper manufacturing), sandalwood (essential oils, carving and incense) to high value musical instruments, flooring and outdoor furniture. For the high value group, fluctuating environmental conditions brought on by changes in temperature and relative humidity, can lead to performance problems due to consequential swelling, shrinkage and/or distortion of the wood elements. A survey determined the types of value-added products exported, including species and dimensions packaging used and export markets. Data loggers were installed with shipments to monitor temperature and relative humidity conditions. These data were converted to timber equilibrium moisture content values to provide an indication of the environment that the wood elements would be acclimatising to. The results of the initial survey indicated that primary high value wood export products included guitars, flooring, decking and outdoor furniture. The destination markets were mainly located in the northern hemisphere, particularly the United States of America, China, Hong Kong, Europe (including the United Kingdom), Japan, Korea and the Middle East. Other regions importing Australian-made wooden articles were south-east Asia, New Zealand and South Africa. Different timber species have differing rates of swelling and shrinkage, so the types of timber were also recorded during the survey. Results from this work determined that the major species were ash-type eucalypts from south-eastern Australia (commonly referred to in the market as Tasmanian oak), jarrah from Western Australia, spotted gum, hoop pine, white cypress, black butt, brush box and Sydney blue gum from Queensland and New South Wales. The environmental conditions data indicated that microclimates in shipping containers can fluctuate extensively during shipping. Conditions at the time of manufacturing were usually between 10 and 12% equilibrium moisture content, however conditions during shipping could range from 5 (very dry) to 20% (very humid). The packaging systems incorporated were reported to be efficient at protecting the wooden articles from damage during transit. The research highlighted the potential risk for wood components to ‘move’ in response to periods of drier or more humid conditions than those at the time of manufacturing, and the importance of engineering a packaging system that can account for the environmental conditions experienced in shipping containers. Examples of potential dimensional changes in wooden components were calculated based on published unit shrinkage data for key species and the climatic data returned from the logging equipment. The information highlighted the importance of good design to account for possible timber movement during shipping. A timber movement calculator was developed to allow designers to input component species, dimensions, site of manufacture and destination, to see validate their product design.

Effect of citrus peel chemicals on Bactrocera tryonilarval survival

Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) is a major horticultural insect pest in Australia which significantly limits domestic and international market access for Australian horticultural produce. Citrus is one of the industries seriously affected by the fruit fly problem in Australia. This research investigated the effect of citrus peel essential oil chemicals on B. tryoni larval survival in five different commercially important Citrus species and cultivars as a way of better understanding fruit susceptibility. The fruits used were Murcott Mandarin, Navel orange, Eureka lemon, Valencia orange and yellow grapefruit. The essential oils of each citrus type were extracted using hydrodistillation and then mixed, at different concentrations, with artificial larval diets to which B. tryoni eggs were added. Surviving larvae were counted after five trial days. The same process was repeated for six essential oil components. Regression analysis of increasing oil concentration against larval survival showed that the crude oil blends of Navel orange, Eureka lemon and yellow grapefruit had significant negative effects on B. tryoni larval survival, but no such effects were seen for Murcott Mandarin and Valencia orange. Of the individual essential oil fractions, only D-limonene had a significant effect on B. tryoni larval survival, with this chemical being highly toxic at very low concentrations. The results of this study open up opportunities for incorporating B. tryoni resistance mechanisms into citrus through minor peel property changes which would not impact on the eating attributes of the fruit.