RIRDC Completed Projects in 2002-2003 & Research in Progress as at June 2003

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To Essential Oils Research in Progress

2.4 Essential Oils - Completed Projects
PROJECT No	PROJECT TITLE	RESEARCHER	PHONE	ORGANISATION

Development and Improvement of Products

DAQ-269A	The control of chalkbrood disease with natural products (eg essential oils)	Dr. Craig Davis	(07) 3406 8611	Dept of Primary Industries (Qld)
DAV-168A	Kesom oil a new essential oil for flavours	Mr. Fred Bienvenu	(03) 5731 1222	Dept of Natural Resources & Environment (Vic)
UNC-6A	Generation of high quality Australian Skullcap products	Prof. Ron Wills	(02) 4348 4140	The University of Newcastle
UNC-11A	Generation of high quality Australian valerian products	Prof. Ron Wills	(02) 4348 4140	The University of Newcastle
UT-27A	Optimisation of parsley seed oil production	Prof. Robert Menary	(03) 6226 2723	University of Tasmania

Improved Production Systems

UNC-13A

Optimisation of polysaccharides in processed echinacea purpurea products

Dr. Douglas Stuart

(02) 4548 4124

The University of Newcastle

Understanding of Markets

AMR-9A

The world market for onion oil

Mr. Grant Vinning

(07) 3376 2244

Asian Markets Research


 

Project Title:	The control of chalkbrood disease with natural products
RIRDC Project No:	DAQ-269A
Researcher:	Dr Craig Davis
Organisation:	Queensland Department of Primary Industries
Phone:	(07) 3406 8611
Fax:	(07) 3406 8677
Email:	craig.davis@dpi.qld.gov.au
Objectives:	To conduct a laboratory study on the efficacy of natural products against Chalkbrood fungi and to develop an appropriate field treatment plan to evaluate the products identified above.
Background:	Despite the broad range of experimental work that has been carried out to develop chalkbrood control strategies, there is no specific strategy that has been universally adopted or accepted by beekeepers around the world. Management strategies, chemicals and the use of bees that show resistance to chalkbrood have all been shown to have some benefit although no individual control strategy will ensure a cure for the disease. The effective control of chalkbrood will probably require a combination of control strategies. The fact that A. apis is so widespread makes the possibility of its eradication unlikely. If the disease cannot be eradicated, then any chemical that is considered for use against chalkbrood must be demonstrated to produce minimal residues in honey or other bee products. Long-term use of any chemical for disease control is likely to result in the development of resistance to that chemical. However, the use of a chemical that controls chalkbrood and does not produce residues in honeybee products would be of benefit to beekeepers, even if A. apis did develop resistance. In the long-term, the development of antibiotic resistance by a honeybee pathogen has already occurred in the beekeeping industry in several countries where American Foulbrood has developed resistance to oxytetracycline. The effective control of chalkbrood will probably require a combination of control strategies. This project has attempted to identify and test candidate chemicals for the control of chalkbrood disease.
Research:	The susceptibility of the chalkbrood fungi to a range of treatments have been examined in the laboratory. The treatments which have been studied so far include a selection of natural products (e.g. essential oils). More than 40 essential oils have been assessed including native (tea tree oil, lemon myrtle oil and Manuka oil) and exotic spice oils (like sage, rosemary and clove oil). Fatty acid derivatives (e.g. glycerol monolaurate), and an extract from banana were also tested. The current knowledge in this area has been reviewed and will be presented with the final report, along with an outline for a field trial for the evaluation of the most active and appropriate anti-microbiological agents in experimentally-infected hives. If these trials are subsequently undertaken, the success of treatments will be assessed by regular examination for disease development and culture of adult bee samples for Chalkbrood. This work has the potential to improve the economic viability of the Australian apiarist while producing an effective and environmentally-sound treatment regime.
Outcomes:	In our investigation, two strains of Chalkbrood fungus were obtained from mummies of naturally infected hives in two widely diverse areas of Queensland. The most active antifungal test agents in this study were Nepalese Lemon Grass oil, Lemon Scented Eucalyptus (Eucalyptus citrodora) oil, Lemon Scented Tea Tree (Leptospermum petersonii) oil and a particular fraction of a New Zealand Manuka (Leptospermum scoparium) oil. All of these agents presented with a Minimal Fungicidal Concentration against Ascosphaera apis of 250 ppm. Citral is the major component of the former three oils while the active chemical in the New Zealand Manuka (Leptospermum) oil is a unique terpenoid agent (leptospermone).  This project has also proposed a field test system to assess the efficacy of the most active antifungal agents identified in the in vitro assay system presented in this report (see Appendix 3). There are few reports in the literature of field trials of natural products against bee diseases, and even fewer investigating the efficacy of natural products against the causative agent of chalkbrood in an apiary system.


 

Project Title:	Kesom Oil - New Essential Oil for Flavours
RIRDC Project No.:	DAV - 168A
Researcher:	Fred Bienvenu
Organisation:	Ovens Research & Development Unit, Dept. Primary Industries P.O. Box 235, Myrtleford VIC 3737
Phone:	0357311203
Fax:	0357311223
Email:	fred.bienvenu@dpi.vic.gov.au
Objectives	· To develop of an effective weed control protocol · To establish effects on oil yield and composition due to agronomic factors · To evaluate market opportunities through industry linkages · To establish of likely costs of production
Background	Kesom oil is distilled from Persicaria odorata providing a natural source of n-decanal C10 (~ 25%) & dodecanal C12 (~55%) as major components. These oil components are currently obtained from synthetic sources. P. odorata offers an opportunity to produce natural decanal and dodecanal on a commercial scale. To successfully commercialise wild plants in monoculture, one of the major problems is weed control. Effective weed control and a suitable nutrition strategy are needed for Kesom oil to become a low cost/high return adjunct to the peppermint industry.
Research	Research strategies included:- · developing an effective weed control protocol for a plant closely related to many weed species using selected herbicide strategies · understanding oil yield and composition effects of rate/time of nitrogen application and time/number/height of harvests  · examining market opportunities through industry linkages, for a range of Kesom oils/components produced under commercial conditions · estimating likely costs of production of a commercial scale Kesom oil production system
Outcomes	· An effective weed control strategy has been developed using a range of herbicides targeting local weed spectra. · In most cases oil yield response to nitrogen application peaks at 90kg/ha(actual N). Changes in nitrogen have almost no effect on the levels of the four major oil components decanal, dodecanal, decanol and dodecanol. · Height of cutting of Kesom does not effect oil yield but oil composition was affected by height of cutting. Cutting increased stem length led to reductions in decanal and dodecanal and increasing decanol and dodecanol levels. · A full chemical analysis of locally produced Kesom oil based on GC/MS is reported. · An analysis of market acceptance to Kesom oil was commenced. · An estimated gross margin for Kesom oil production has been determined.
Implications	Kesom oil can be produced in association with peppermint oil production in south eastern Australia. Weeds can be controlled using protocol outlined. Nutrition and harvest techniques are better understood. Further work is required to enable acceptance of Kesom oil by international flavour and fragrance markets.


 
 

Project Title:	Generation of high quality Australian Skullcap products
RIRDC Project No.:	UNC-6A
Researcher:	Professor R.B.H. Wills and Dr D.L. Stuart
Organisation:	University of Newcastle
Phone:	(02) 43484140
Fax:	(02) 43494565
Email:	Ron.Wills@newcastle.edu.au
Objectives	The project determined the flavonoid compounds in skullcap (Scutellaria lateriflora) and changes during growth, postharvest handling and processing with the aim of optimising handling and processing systems for retention of quality in end products.
Background	Skullcap is a medicinal herb with the aerial parts used as a sedative. Skullcap quality is related to the constituents that impart a health benefit with the major constituents of interest being the flavonoids. Recent events in the Australian therapeutic goods industry have emphasised the need for consumers to be assured of high medicinal quality in products.
Research	The research objectives were to develop an effective method for analysis of flavonoids, and determine changes in flavonoids in plant parts during plant growth, postharvest handling and processing, and in retail products.
Outcomes	15 flavonoids in skullcap were identified with 40-50% of the total being baicalin. The flavonoids concentration was leaf>root>stem. They were highest in immature leaf although the total yield of flavonoids was highest in the larger plants at the current commercial stage of harvest. Mechanical stressing but not cutting of fresh plants resulted in a loss of flavonoids. Undamaged plants showed little loss of flavonoids if held for 30 days in ambient conditions although the rate of water loss was rapid. Drying plants in a hot air drier was faster as the temperature increased from 40-70° C but with no additional decrease in flavonoids. Storage of dried skullcap at 5-30° C in low and ambient RH showed a loss of flavonoids of about 0.05 mg/day except at high RH where moisture absorption occurred and the loss was 0.85 mg/day. Maximum extraction of flavonoids from dried skullcap with aqueous ethanol was 70% of the total with 40-60% ethanol. Storage of extracts showed a 0.17% loss/day, twice that of dried skullcap. Commercial solid products consisting only of skullcap showed a typical skullcap flavonoids profile but a liquid was more consistent with S. incana. Five mixed herbal products did not contain all the skullcap flavonoids and only one product contained the expected level of flavonoids.
Implications	The leaf is the preferred plant section for quality but the root is superior to the stem. Careful handling after harvest is required especially to prevent mechanical stressing.  Holding fresh plants in ambient conditions seems a viable method of almost drying plants. Hot air drying of skullcap at 70° C seems a feasible quality option with cost advantages. Storage of dried skullcap at 5° -30ºC and protected from water uptake resulted in a 0.1% loss of flavonoids per day and can be a quality issue for long term storage.  Maximum extraction of flavonoids is at 40-60% ethanol.  Long term storage of extracts results in a commercially significance loss of flavonoids.  The medicinal quality of commercial products is highly variable.
Publications	No publications have yet been generated.


 
 
 

Project Title:	Generation of high quality Australian valerian products
RIRDC Project No:	UNC-11A
Researcher:	Professor R.B.H. Wills and Ms D. Shohet
Organisation:	University of Newcastle
Phone:	(02) 43484140
Fax:	(02) 43494565
Email:	Ron.Wills@newcastle.edu.au
Objectives	The project studied changes in the valerenic acids in valerian during growth, postharvest handling and processing operations with the aim of identifying varieties with high levels of valerenic acids and optimising handling and processing systems for retention of quality in end products.
Background	Valerian root is a medicinal herb used for the treatment of tension, irritability, restlessness and insomnia. It is the fourth best selling medicinal herb in Europe and is in the top 10 in Australia. The Australian industry needs to develop systems that generate high quality products in order to replace imports of dry concentrate and create export markets. Valerian quality is related to the constituents that impart a health benefit with the major constituents of interest being in the valerenic acids with the valepotriates and essential oil, also of interest.
Research	The project aim was to assist the Australian industry to improve the quality of Australian grown valerian. The research objectives were to determine the level of valerenic acids in valerian seed obtained from diverse sources, changes in the root during plant growth, postharvest handling and processing and in retail products.
Outcomes	The valerenic acids in commercial Anthos roots were about 3 mg/g but 5 new seed sources were found to generate levels >4 mg/g. The concentration of valerenic acids during a growth cycle was maximal in spring but the yield per root increased with root age due to linear growth of roots throughout the season. Cutting and soaking roots did not allow faster soil removal but reduced drying time with greater retention of valerenic acids. Drying time was related to temperature but loss of valerenic acids occurred above 40° C. Valerenic acids were unstable in storage with increased losses at higher temperature, lower humidity and exposure to light. Increased extraction of valerenic acids from dried valerian was obtained by percolation with increasing ethanol in aqueous mixtures up to about 70:30 ethanol:water. Supercritical fluid extraction with CO2 was found to also be an efficient extraction method. Retail products showed considerable variation in valerenic acids from <0.01 to 6.32 mg/g with 20% containing >2 mg/g and 16% <0.1 mg/g.
Implications	· Quality of Australian valerian could be raised by introducing different cultivars; · Separate drying of rootlets and crown at 40° C reduces drying time and enhances quality; · Losses during storage are minimised at low temperatures, high humidity and dark; · Current use of 60:40 ethanol:water by percolation is an efficient extraction solvent; and · Quality of retail valerian products is highly variable.
Publications	Shohet, D., Wills, R.B.H. & Stuart, D.L. (2001). Valepotriates and valerenic acids in commercial preparations of valerian available in Australia. Pharmazie 56: 860-3.


 

Project Title:	Optimisation of Parsley Seed Oil Production
RIRDC Project No.:	UT-27A
Researcher:	Professor R. C. Menary & Dr L. Falzari
Organisation:	University of Tasmania
Phone:	03 6226 2724
Fax:	03 6226 7609
Email:	R. Menary@utas.edu.au
Objectives	· Locate and test parsley varieties suitable for parsley seed oil production. · Examine oil recovery and losses in the commercial separator.
Background	Parsley herb oil is currently grown in Tasmania. Parsley seed oil is a by-product from this industry and the quality of the product has to be improved to meet international standards and specific needs.
Research	Parsley varieties, Napoli and Dark Green were found to produce seed oil of commercial standard. The recovery of the main component, apiole, proved difficult because its density was similar to that of water and it was therefore difficult to separate. Further, it has a high boiling point and is slow to distil. Recommendations were made for optimum distillation time and separation techniques.
Outcomes	Industry interest is high and the production of a quality seed oil is assured.
Implications	Strong links between industry and researchers and extensive background experience in the production and marketing of essential oils has led to the development of a new product which will increase the Tasmanian export product range and increase gross margins to growers.
Publications	The experimental work will be prepared for publication in international journals.


 
 
 

Project Title:	Optimisation of polysaccharides in processed Echinacea purpurea products
RIRDC Project No.:	UNC-13A
Researcher:	Dr. Douglas Stuart and Prof. Ron Wills
Organisation:	The University of Newcastle Centre for Food Industry Research and Development PO Box 127 Brush Road OURIMBAH NSW 2258
Phone:	(02) 4548 4124
Fax:	(02) 4348 4145
Email:	ftdls@cc.newcastle.edu.au
Objectives	To determine if echinacea extracts based on polysaccharide content could be grown and processed in Australia to eliminate the need for imported equivalents and develop a potential export market. The success of the project will encourage alternative crops of echinacea and other medicinal herbs within the primary producing and manufacturing sector.
Background	The active constituent groups within echinacea are the caffeoyl phenols, alkylamides and polysaccharides. We have previously investigated the alkylamides and caffeoyl phenols in postharvest and processing steps of alcoholic extracts, and have developed a guide outlining optimum conditions for growers and processors to maximise these constituents. This study will provide additional information for growers and processors who are interested in preserving the polysaccharide content.
Research	The concentration of polysaccharides was determined in each plant section during growth. The behaviour of the polysaccharides was determined in postharvest handling techniques of drying and storage, while processing of plant material into liquid extracts was investigated for fresh plant material and dried plant material.
Outcomes	The stem and root had the highest concentrations at 12 mg/g, with the leaf at 7.7 mg/g and the flower at 5.1 mg/g. The northern tablelands returned higher concentrations of polysaccharides per plant within the first season of growth and was similar to the coast in the second season. Fresh plant material has a limited storage time after harvesting as 50% of polysaccharide concentration was lost within the first 10 days of fresh material storage. The study on drying indicates that level of polysaccharides are affected by the drying temperature, and suggests that optimal drying occurred at 70°C and 40°C with significantly lower returns between these temperatures. This study found that polysaccharides were highly susceptible to storage of dried crushed material. Degradation is slightly minimised if material is kept at low humidity, though loss is still significant (40% in 3 days). Maximum extraction of 3-4% for polysaccharide 1 and 14-16% for polysaccharide 2 found that processing is highly undesirable for dried crushed material. In contrast to this was an extraction of 25% for polysaccharide 1 and 70% for polysaccharide 2 in fresh material extraction processing.
Implications	This project has shown that specific postharvest handling and processing requirements are needed to maximise individual active constituents with E. purpurea. These requirements are different for the polysaccharides, caffeoyl phenols and alkylamides. Consequently, if these recommendations are not followed, lower amounts of active constituents will be available.
Publications	Nil


 
 

Project Title	The world market for onion oil
RIRDC Project No:	AMR-9A
Researcher:	Mr. Grant Vinning
Organisation:	Asian Markets Research PO Box 371 SUMNER PARK QLD 4074
Phone:	(07) 3376 2244
Fax:	(07) 3376 7264
Email:	grant.vinning@asianmarketsresearch.com.au
Objectives	· Establish the world market for onion oil. · Use this data to establish a business plan for the commercialisation of the Tasmanian onion oil industry.
Background	The RIRDC has funded research into the production of onion oil as a means of establishing if the waste and surplus product from the Tasmanian onion industry could be profitably utilised.
Research	The onion oil industry is extremely small. There is virtually no production, trade or marketing data available. What price data is available must be related to the actual quality of the oil as enhancement is extremely common. Considerably sophisticated equipment is needed to establish "quality". Qualitative market research was undertaken in the United Kingdom and Japan.
Outcomes	It is estimated that onion oil should attract in the Japanese market a price of around Y150 000 / kg, CIF basis. The closed nature of the industry does suggest that any new entrant to the market can expect strong price competition. It is possible that Tasmania’s pristine production conditions may militate against the production of high quality onion oil.
Implications	Unless a cost effective method can be established to produce a high quality product, a Tasmanian onion oil industry could struggle to be financially viable.
Publications	No publications have yet been generated.