Tobacco belongs to Solanaceae, Nicotiana, 66 species of Nicotiana have been found. At present, the main cultivated species are Nicotiana tabacum and Nicotiana tabacum, and most of the rest are wild. Safflower tobacco is also common tobacco. More than 90% of tobacco cultivars are safflower tobacco, and yellow flower tobacco is cultivated in a small amount in parts of Asia.
In the process of long-term cultivation, tobacco has formed many types due to differences in usage requirements and preparation methods, cultivation conditions and natural environmental conditions. Tobacco is classified according to quality characteristics, biological shape, and cultivation and modulation methods. It can be divided into four types: flue-cured tobacco, air-cured tobacco, sun-cured tobacco, and smoked tobacco; according to tobacco product classification, it is divided into cigarettes, pipe tobacco, hookah, cigars, snuff and Chewing tobacco, etc.
Also known as fire-tube flue-cured tobacco, is native to North America. It mainly uses fire tubes to conduct heat to modulate tobacco leaves. The leaves are not in direct contact with the fire. It is the largest and most productive tobacco type in China and the world, and it is also the main raw material for the cigarette industry. Flue-cured tobacco plants are large, with uniform and sparse leaf distribution. The plant is generally more than 1 meter high, with 20-30 leaves per plant. The middle leaves are of the best quality, and the leaves are harvested in stages from bottom to top. After the tobacco is harvested, it is roasted in the curing barn. During the roasting process, it undergoes a series of changes and finally turns yellow and dried. The world’s flue-cured tobacco production areas are mainly in China, the United States, India, Brazil, Canada and Zimbabwe, etc.
A natural modulation method. Generally, direct sunlight is not allowed during air-curing, but the leaves are placed in a cool and ventilated place to complete the process of natural yellowing. According to the variety and cultivation method, it is divided into the following types:
Ordinary air-cured tobacco
When the middle tobacco leaves are basically mature, the whole plant is cut, placed on the ground for a period of time to evaporate part of the leaf water, then put in a ventilated room, and the whole plant is hung until the leaves and main veins are all dry. Take off. There are dark-colored air-cured tobacco and light-colored air-cured tobacco.
Originated in the United States, it is a mutation of Maryland broadleaf tobacco. Except for the light green leaves, the veins and base of the leaves are milky white, hence the name Burley tobacco. The preparation method is to harvest the leaves one by one and hang them in the pergola to dry. In recent years, when the middle leaves are mature, the plants are pulled up from the field, so that they are hung in the drying room after losing part of the water in the field. The middle and lower leaves of burley tobacco are thin and large, grow faster, mature and concentrate. The sugar content of the leaves is lower. The content of nicotine and total nitrogen is higher than that of flue-cured tobacco. Because the leaves are thin and elastic, the filling power is high, and the smoldering keeps the firepower strong. Therefore, it is an indispensable raw material for hybrid leaf rolls. Burley tobacco produces the most in the United States, and the quality is the best in the United States and South Korea.
It is a kind of light-colored air-cured tobacco in the United States, originally produced in Maryland, the United States. Generally, the whole plant is harvested and air-cured. The leaves are thin and rough, with low nicotine content and strong combustibility. When mixed with other types of tobacco leaves, it can improve the smoldering properties of cigarettes without disturbing the flavor. The content of tar and nicotine in Maryland tobacco is lower than that of flue-cured tobacco. It has good filling and combustibility and is the main raw material for producing mixed cigarettes.
It is a special type of tobacco in Louisiana, USA, which has been cultivated there for many years. Each plant leaves 12-14 leaves, and the whole plant is harvested and hung in the room to dry.
Sun-dried tobacco mainly uses sunlight to dry the tobacco, which is also an ancient method of modulation. However, it is not directly exposed to the hot sun. This will make the leaves dry and affect the quality of the tobacco leaves. Therefore, direct sunlight should be avoided to slow down the drying speed. After the internal changes have been completed, the leaves will be dried to allow them The color and quality are fixed. Sun-cured tobacco can be used as the main raw material for pipe tobacco, dry tobacco, cigarettes, cigars, nasopharynx, and chewing tobacco.
The tobacco leaves after sun-curing are yellowish-brown or reddish-brown, with low sugar content, high protein and nicotine content, strong flavor and large ends. Mainly used as raw materials for mixed cigarettes and cigars.
Yellow sun-cured tobacco
It is formed under the conditions of low soil fertility, high topping and less fertilization. It is between flue-cured tobacco and sun-cured tobacco in terms of cultivation and tobacco leaf quality characteristics. The leaves of a single plant are slightly less than that of flue-cured tobacco. It is a raw material for blended cigarettes, flue-cured cigarettes and cigars.
The main producing area is in the eastern coastal zone of the Mediterranean, so it is also called Oriental tobacco or Turkish tobacco. Because its leaves have a special strong fragrance, especially the upper leaves have the strongest fragrance, it is called Oriental tobacco. The preparation method is half drying and half drying, and then exposure to the sun when it withers and turns yellow. In ordinary tobacco, the leaves are the smallest, only 5-20 cm long, each plant has about 30 leaves, and the plant height is 80-100 cm. There is no topping during the cultivation process, and the sugar content is low. It is an important raw material for mixed cigarettes. The main producing areas of oriental tobacco are Greece, Turkey, Bulgaria and other places
The difference from the above-mentioned types is that it belongs to different species in botanical classification and shows great differences in biological characteristics. The corolla is yellow, smaller than Nicotiana tabacum, with larger seeds, and the height of the plant is 50-100 cm. . It has 10-15 leaves, small, ovoid or heart-shaped, and stalked. Its biological characteristics are also different from safflower tobacco. It has a short growth period and is cold-tolerant. It is mostly planted in high latitudes and high altitude areas with short frost-free periods. Because the tobacco leaves after preparation have higher nicotine, total nitrogen, and protein content, and lower sugar content, the tobacco has a strong flavor and is the main raw material for waterpipe, pipe tobacco and chewing tobacco. Russia grows more
Smoke, in the early days, colonists transported tobacco leaves all over the world. In order to prevent the tobacco leaves from becoming moldy, they smoked the tobacco leaves on a fire before transporting them. Now the method has been improved. It is to start a fire in the room to dry the tobacco leaves, so it is called fumigation. Because the tobacco leaves are in direct contact with the smoke, the tobacco leaves are darker in color and have a strong special flavor. They are used in conjunction with the production of cigarettes, chewing tobacco, snuff and cigars. The tobacco varieties used for smoking are generally dark air-cured tobacco, and some varieties of flue-cured tobacco. The tobacco contains higher nitrogen content and lower sugar content after preparation. Now the United States, Canada, Spain, Italy, Zimbabwe and other places still retain this modulation method.