AUSTRALIAN GARLIC FOR PHARMACEUTICAL USE?

Samantha Sterling,
Institute for Horticultural Development, Knoxfield, Tel. (03) 9210 9222

Garlic (Allium sativum) has been utilised for centuries as a health-giving vegetable in Asia and Europe. Until recently, Australia has been slow to realise this potential but garlic is now becoming an important crop.

With an overwhelming amount of medical studies now confirming the positive effects of garlic on the immune system, bloodstream and heart, a new market in processing garlic for pharmaceutical products may be on the horizon. Australia finds itself in a strong position to participate in these potential new markets. Research has shown Australian garlic contains higher than average levels of the main health-giving compound in garlic, alliin. Studies conducted at the Institute for Horticultural Development (IHD) for the past two and a half years have recorded alliin levels above 20mg/g by fresh weight (FW), which are higher than any levels previously published (world-wide).

More importantly, Australian growing conditions have been shown to consistently produce high levels of alliin (in the order of 10-15mg/g FW) for many regions of Eastern Australia. It is this ability to consistently produce pharmaceutically superior garlic crops that may lead to new markets for Australian garlic in the future.

The regions tested including Queensland, New South Wales (NSW), Victoria, South Australia and Tasmania have returned alliin results in the desired range for pharmaceutical interests - above 10mg/g FW. This has meant that a large number of different garlic varieties have proved capable of producing the desired levels of alliin, as different varieties are grown in different regions dependent on the climate. Hence all regions of Australia are able to participate in growing pharmaceutical garlic crops (with some care taken in selecting the particular variety to be grown in each region) should the market opportunities eventuate.

Further studies are now underway to determine best practice methods for growing garlic crops with a pharmaceutical outlet in mind, taking into account strategies for enhancing alliin content of bulbs rather than looking at common domestic and export market requirements such as size, colour and flavour.

This work is being conducted at IHD, Knoxfield in conjunction with Pharmaction Pty Ltd. Enquiries can be directed to Samantha Sterling.

GARLIC *

Garlic (Allium sativum) comes from the family Alliaceae the same family as onions and leeks. A herbaceous biennial, it grows to 40-60 cm in height. The leaves are flat, 5-6 cm long and 1-3 cm wide. There are two types of plants: one with soft tender leaves, the other with hard leaves. The garlic bulb develops entirely below the ground.

Each garlic variety can differ in shape and colour of leaves and bulb (white or a purplish pink) and the number and size of cloves present. Such differences can be caused by a change in environmental conditions. Australian garlic tends to be larger in size (7.5-8cm in diameter) than the imported Chinese garlic (4.5-5cm in diameter) that is commonly seen and readily available in the domestic markets. Australian garlic is stronger in flavour and contains higher levels of the health-giving compound alliin than garlic grown elsewhere.

Nutritional Value In every 100g of fresh bulb there is:
61.3 g water 6.2 g protein 0.2 g fat 5 mg calcium 0.4 mg iron 15mg Vitamin C	30.8 g carbohydrates 44 mg phosphorus 0.25 mg Vitamin B1 0.8 mg Vitamin B2 0.5 mg niacin

To the Chinese, garlic is a 'warming food', a powerful tonic for the digestive and respiratory systems. In the colder northern provinces of China, raw garlic is routinely eaten to kill worms and to prevent and/or treat dysentery and pneumonia. Excess garlic is however believed to harm the stomach and liver.

Preparation
Garlic has a distinct flavour. For maximum development of the flavour, garlic should be thoroughly minced or crushed. The myriad uses of garlic are well known.

Chinese Cooking
Position unpeeled clove(s) on the chopping board. Using the broadside of a heavy cleaver, crush the garlic with a single blow. The husks would have fallen away from the inner clove which is now ready for use.
Garlic can be stir-fried with leafy vegetables or braised whole in casseroles.
Should only a touch of garlic be desired, add crushed garlic to hot oil, then remove and discard from the oil before cooking proceeds. Alternately, use garlic shoots.

Western Cooking
Garlic can be used wherever onions are used - salads, salad dressings, roasts, casseroles, stir-frys

Cultivation
Garlic is propagated from individual cloves. No seed is produced by the plant. Depending on the variety, each clove planted propagates an entire bulb consisting of 10-15 cloves at harvest.

Garlic is planted in March-April in NSW and Victoria, earlier in the warmer climates of Queensland and later in cooler areas such as Tasmania. There are a large number of different varieties available and it is important to choose a variety suitable for the climate in which the crop is to be grown. Harvest is in summer (December-February). Garlic can be grown on a wide range of soil types, but prefers well drained soils with a relatively neutral pH. Fertiliser rates are best determined with a pre-plant soil test and side-dressing will be necessary due to the length of the growing season. This is usually based on leaf tissue analysis throughout the season. Applications of nitrogen are stopped before the initiation of bulbing to avoid problems with side-shooting.

Irrigation is essential to ensure the plants are never stressed for water. The supply of water to the plant is stopped as the bulb reaches maturity. Watering at this stage often causes staining and can lead to storage problems.

Weed control is important and is initiated with a pre-emergent herbicide. This allows the plants to become established without too much competition. Regular applications for both broad leaf and grass weeds are required throughout the season. They are applied on an "as necessary" basis to ensure that weeds never impinge upon the crop.

Viruses are inherent in garlic and often expressed when other factors cause difficulties for the plant. Virus is usually a symptom of another problem, rather than the problem itself. This can be contained by optimising management practices.

Pests and diseases of garlic include downy mildew, white rot, purple blotch, nematodes and onion thrips. Problems should be investigated early and proper identification sought. Use management practices such as avoiding areas previously used to grow garlic or onions and screening "seed" material carefully before bringing it onto the property to reduce the risk of disease problems.

Harvest
One indication that the crop is ready to harvest is when the outer leaves dry out and fall over. This signifies nutrient withdrawal (from the leaves down into the bulb) is well progressed. Once removed from the ground, bulbs are left to "dry" or "cure" for a period of weeks. This is done in a dry, well-ventilated area out of direct sunlight. Tops usually remain attached during this period, to allow the process of nutrient withdrawal to continue. Once cured, bulbs have their tops (leaves) and tails (roots) removed and are prepared and packed for market.

Market Information
Although Australian grown garlic is often a premium product, local buyers are largely unaware of the differences between local and imported lines. Hence market opportunities are perhaps more limited than they should be. Most Australian garlic is sold through the wholesale markets. There are also a number of niche markets available that avoid the need for distribution through the wholesale markets. These niche markets include organic garlic and value added products, and require informed choices as to the varieties, production practices and marketing methods to be employed.

* For additional information see also our Vegetable Thesaurus

PICK FROM THE BOOK SHELF

In each newsletter we will present a brief summary on one of RIRDC's publications on Asian Foods. This month's issue looks at

Review of the Market Potential for Indigenous Indian Dairy Desserts
Suku Bhaskaran, Australian Food Marketing Centre
Peter J Irwin, Murray Goulburn Co-operative Co Ltd
RIRDC Research Paper 95/6, 127 pages, $30 ($6 p&h)

Evaluates the opportunities for Australian dairy companies to manufacture and market indigenous dairy desserts in India. Suggests that India could provide opportunities for market diversification as dairy products make up a significantly important portion of the Indian diet.

The book can be purchased from
Rural Industries Research and Development Corporation (RIRDC)
P O Box 4776, Kingston, ACT 2600, Phone: (02) 6272 4819, Fax: (02) 6272 5877
Webpage: http://www.rirdc.gov.au/

For more RIRDC publications see our first 'Asian Foods' Newsletter.