The genus Cinnamomum

164 Nguyen Kim Dao
A better method for the preparation of bark, but which is more complex, is prevalent
in certain areas in Vietnam. Here peeled cassia bark is put in fresh water right after
peeling for about 24 hours. The bark is then cleaned, washed and dried in a shady place
until it is apparently dry. Such bark is then kept in layers in a bamboo basket lined and
separated with dry banana leaves. The top layer is covered with dried banana leaves and
compressed by stones for 24 hours. The basket is then turned upside down and kept for
20–24 hours more. The bark is then washed and put on bamboo screen and dried for
about 15 days in summer and in spring and about 30 days in autumn. In this way, the
quality of the cinnamon bark is good with a better fragrance and taste. It also acquires
an attractive red color. Such processing is practiced only in Vietnam (Khoi, 1991).
Among cinnamon bark categories, the most valuable is the one having the shape of
number 3. It is uniquely produced in Quang Nam (Tra Mi) and Quang Ngai (Tra Bong)
areas of South Vietnam. To get this kind of cinnamon, the bark must be fresh, its thickness
must be over 1.2 cm and its width over 40 cm. Only then the bark may take the
form of number 3 on drying. People in Hong Kong and Taiwan are used to this kind
of cinnamon at the price of $50 (US)/kg. Besides drying, there are some complicated
procedures involved in the processing of this brand, such as waxing the cut ends of the
extremities of the bark, covering the bark with soft cloth and then storing in zinc tubes.
People with large quantities of cassia bark, usually make a double compartmented
wooden box. A honey bowl is kept at the bottom to keep suitable level of humidity, and
the upper compartment has a bottom made of a metal net for keeping the bark. In so
doing, fragrant flavour and taste are ensured. Such elaborate post-harvest handling is
practiced by some Vietnam growers.
In China the peeled bark (from three- to five-year old shoots) is dried in the sun and
bundled. Usually no further post-harvest operations are done by Chinese producers.
When a cleaner product is required the dried bark is washed in fresh clean water, and
dried thoroughly and packed in bundles. In cases where peelings do not come off easily,
the bark is either scraped or chipped (often together with a piece of wood) and dried in
the open and then packed in bags.
Production and International Trade
Cassia bark and leaf oil are economically important. China (Kwangsi and
Kwangtung Provinces) is the main producer and exporter of Chinese cassia. The
harvested area in 1998 was estimated by FAO at 35,000 ha with a production of
28,000 t (Coppen, 1995). Exports of dry bark from China during the period
1966–1976 amounted to 1250–2500 t annually. In 1987–1993 the United States
imported annually about 200 t of cassia bark and 340 t of cassia leaf oil. Given the
considerable domestic consumption in China, the production of leaf oil must be in
excess of 500 t. In 1991–1994 cassia leaf oil fetched a price of about $30–35
(US)/kg (Dao et al., 1999).
In Vietnam, from the early times to the present day, only the bark has been economically
important, while essential oil extracted from leaves and bark has been used only
locally. The harvested area in 1998 was estimated by FAO at 6100 ha with total
production of 3400 t. Exports of dry bark from Vietnam up to 1966–1976 varied from
300 to 500 t. The export, has gone up subsequently and currently it is around 3000 t
(Dao et al., 1999).