Aniseed production
Anise is cultivated in Turkey, Egypt, Spain, Russia, Italy, India, Greece, Northern Africa, Argentina, Malta, Romania and Syria. Anise is primarily exported from Turkey, and also from Egypt and Spain in particular. From an industrial standpoint, the quality differences between anise seed from different origins are not significant and therefore specifications need not limit the spice to a specific country of origin.
P. anisum requires a warm and long frost-free growing season of 120 days. The plant needs a hot summer to thrive and for seeds to ripen. The reported life zone for anise production is 8 to 23°C with 0.4 to 1.7 metres of precipitation on a soil pH of 6.3 to 7.3. Anise develops best in deep, rich, well-drained, sandy and calcerous soils. Cold, loamy and moist soils are unsuitable for the cultivation of anise. The thousand seeds weight of the part-fruits amounts to 1.5 to 3.0 g and should have a minimum purity of 90% and a minimum germination of 70%.
Ripe-fruits seeds germinate relatively quickly. The germination time is 14 days. Only seeds from the previous year’s harvest germinate well. Long storage quickly reduces germination vigour: seeds stored for five years will no longer germinate. Planting begins when the soil in the beds is warmed. Optimum soil temperature for germination is 18-21°C. It is essential to prepare good seedbeds and to create a good contact between the planted seed and the soil because the seeds are small and have low germination percentage (70%). The planting is carried out in spring or autumn depending on the areas it is cultivated. The seeds with a seeding rate of 20-25 kg/ha are sown in rows 20-30 cm apart, at a depth of 1 cm. The plant develops slowly after germination and for the following few weeks it is necessary to control weeds closely. It is recommended to apply fertilizers at a rate of 80-100 kg per hectare. With nitrogen, it is important to be careful, since excessive nitrogen fertilization results in luxuriant vegetative growth with reduced yields, and increased vulnerability to lodging. 50-100 kg/ ha N is normally enough. The small white flowers bloom in midsummer, and seed maturity usually occurs one month after pollination, when the oil content in the dried fruits is about 2.5%. Anise seeds are harvested between from the end of July to the beginning of September, depending on the cultivation areas. Yields of seed up to 500-1000 kg/ha have been achieved. P. anisum is recommended in companion planting to repel aphids and cabbage worms.
The world production of anise oil amounts to 40-50 tons per annum. The most significant importing countries of anise oil are the USA and France. Russia, Spain and Poland are among the largest producers of anise oil. There is no distillation of anise oil and no production of anethole in many of the countries which cultivate the crop.
Anise oil is steam distilled from the crushed seeds of the plant Pimpinella anisum. The process of steam distillation is the most widely accepted process for the production of essential oils on a large scale. A still is charged with plant material to be processed. Steam is introduced at the base of the still and the crushed anise seeds’ volatile elements evaporate with the steam. A condensation process turns this vapour-mix into a liquid form of water and essential oil. The essential oil floats on top of the water and is separated off. The essential oil of aniseed is a colourless to faintly yellow oil which solidifies upon cooling to about 15-19°C due to the crystallization of anethole.
Oleoresin anise is a yellowish-green to orange-brown fluid oleoresin. Volatile oil content of oleoresin anise is 15-18%. The presence of a large quantity of fixed oil in this product limits its shelf-life and the addition of a permitted antioxidant is advised. Anise and anise oil are widely used as flavouring ingredients in all major categories of foods, including alcoholic and non-alcoholic beverages, frozen dairy desserts, sweets, baked goods, gelatines and puddings, and meat and meat products.
Tags: aniseed, production, herbs, spices, cooking