Diospyros kaki

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Diospyros kaki
Kaki 20041002.jpg
Botanical details of buds, flowers and fruit
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Ericales
Family: Ebenaceae
Genus: Diospyros
Species: D. kaki
Binomial name
Diospyros kaki
Thunb.
Synonyms

Diospyros chinensis Blume ('nom. nud.)

Diospyros kaki, better known as the Japanese persimmon, kaki persimmon (kaki [柿]) or Asian persimmon in North America, is the most widely cultivated species of the Diospyros genus. Although its first published botanical description was not until 1780,[1][2] the kaki is among the oldest plants in cultivation, known for its use in China for more than 2000 years. In some rural Chinese communities, the kaki fruit is seen as having a great mystical power that can be harnessed to solve headaches, back pains and foot ache.

The persimmon (kaki) is a sweet, slightly tangy fruit with a soft to occasionally fibrous texture. This species, native to China, is deciduous, with broad, stiff leaves. Cultivation extended first to other parts of East Asia and was later introduced to California and southern Europe in the 19th century, to Brazil in the 1890s,[3] and numerous cultivars have been selected. A variety is Diospyros kaki var. sylvestris Makino.

In many cultivars, known as the astringent varieties, the fruit has a high proanthocyanidin-type tannin content which makes the immature fruit astringent and bitter.[4] The tannin levels are reduced as the fruit matures. It is not edible in its crisp, firm state but has its best flavor when allowed to rest and soften after harvest. It has a soft jelly-like consistency and is best eaten with a spoon. The Japanese 'Hachiya' is a widely grown astringent cultivar. Some cultivars, such as Fuyu, do not contain tannins when firm. They can be eaten like an apple or can be allowed to go to any stage of ripeness, including to the jelly-like stage. These non-astringent varieties are considered to have a less complex flavor.[5]

When ripe, this fruit comprises thick pulpy jelly encased in a waxy thin-skinned shell. "Sharon Fruit" (named originally after Sharon plain in Israel) is the trade name for D. kaki fruit whose astringency has been chemically removed.[6] It is also known as the "Korean mango".

Tree[edit]

Nanyo City, Yamagata, Japan. October 2005.

The kaki tree reaches a size of up to ten meters. It is similar in shape to an apple tree. Its deciduous leaves are medium to dark green, broadly lanceolate, stiff and equally wide as long. It blooms from May to June. Trees are typically either male or female, but some produce both types of flowers. Furthermore, the sexual expression of a tree may vary from year to year. Unusually, the kaki fruits are ripe when the leaves have mostly fallen off the tree (October–November).

Flower[edit]

Kaki trees typically do not bear until they are 3 to 6 years old. The 2-2.5 cm wide flowers appear in the spring. Female flowers have a creamy yellow color and tend to grow singly while male flowers have a pink tint and tend to appear in threes. On occasion, bisexual flowers occur. The flowers have four crown-shaped sepals and four petals. Some varieties (parthenocarpic) will produce seedless fruit in the absence of pollination but if their flowers are pollinated, they will produce larger fruit riddled with seeds.

Fruit[edit]

Main article: Persimmon
Three kaki fruits, one cut open.

The spherical to oval fruit, bearing the indented stem and four sepals, can weigh up to 500 grams. The smooth, shiny, thin shell ranges in shade from yellow to red-orange. The slightly lighter fleshed fruits can contain up to eight seeds and may have an astringent taste. With increasing maturity, the fruit softens, similar to a kiwifruit.

The high content of tannin in the still-immature kaki provides a bitter component reminiscent of pear and apricot flavors, which becomes weaker with progressive maturation. The furry taste, caused by the tannins, is often reduced during the ripening process or by frost. The high content of the carotenoids beta-cryptoxanthin, beta-carotene, and zeaxanthin, along with some lutein and alpha-carotene makes the kaki fruit nutritionally valuable.[7]

Cultivation[edit]

Variety "Koushu-Hyakume" (astringent - for making it a dried kaki)

Kaki are grown worldwide, with 90 percent of production in China, Japan and Korea. In East Asia the main harvest time for kaki is in the months of October and November. The trees have lost their leaves by the time of harvest. Occasionally, the brightly colored fruit is left unharvested on the tree as a decorative effect.

In China, kaki has been cultivated since time immemorial. It is considered to have four virtues:

  • It lives long.
  • It gives a large area of shade.
  • It is used by the birds as a nesting place.
  • It is not attacked by pests.

A vase adorned with a kaki cake, a pine branch and an orange is a symbol of the desire "great happiness in 100 affairs".

Throughout Asia, healing properties are attributed to the kaki. They are said to be helpful against stomach ailments and diarrhea. Immature fruits are said to be a treatment for fever, if they ripen in containers until they are sweet as honey. The juice of unripe fruit is said to lower the blood pressure and the fruit stem to relieve a cough. To reinforce these effects, the fruit is peeled before use, exposed to the sunlight during the day and to the dew at night, until a white powder coating forms.

Cultivation of this species at first spread through East Asia. Since the 19th century, kaki partially replaced date-plum (Diospyros lotus, also known as Caucasian persimmon) in some countries of South Europe and West Asia, because kaki has bigger fruits than date-plum; cultivation in California began at that time.

The "Sharon" is a variegated form of kaki from Israel, named after the fertile Plain of Sharon. It does not contain seeds and tastes more mild, since it clearly contains less tannin. Cross cut, the Sharon shows a star-shaped pattern of lines with darker flesh.

In Spain, there is a variegated form of kaki, the "Ribera del Xuquer" of the Valencia region.

Kaki is also produced in Albania, mainly in Elbasan region.

Consumption[edit]

Remove the leaves before serving. The skin can be eaten (especially when the fruit is ripe and the tannins are almost completely decomposed), but many remove the skin before eating. Dried (after skinning and rinsing with Shōchū or after leaving 24 hours in hot spring water). 2 fruits are attached by a string which is then hung over a pole.

In Korea, the persimmon is called gam (Korean: 감), and it is usually eaten as a dessert or when there are guests at home. The persimmon is usually cut into sections and the skin and core is usually removed. Persimmons were eaten dry during the winter, and they were highly sought after by many children. In autumn, families and farmers from the rural areas collect persimmons and hang them to dry. Powdered sugar is sometimes added to enhance the sweetness.

Chemistry[edit]

Apart from tannins, triterpenoid compounds such as α-amyrin, uvaol, ursolic acid, 19α-hydroxy ursolic acid and 19 α,24-dihydroxy ursolic acid can be isolated from the leaves of D. kaki.[8]

References[edit]

  1. ^ Published in Nova Acta Soc. Sc. Upsal. iii. 208, author Carl Peter Thunberg, [Thunb.] (1780); later in Fl. Jap. 157, author Thunb. (1784)."Plant Name Details for Diospyros kaki". IPNI. Retrieved October 12, 2009. 
  2. ^ "Diospyros kaki Thunb.". Germplasm Resources Information Network. United States Department of Agriculture. 2007-01-28. Retrieved 2009-04-09. 
  3. ^ The Japanese persimmon was first introduced to the State of São Paulo, afterward expanding across Brazil through Japanese immigration; State of São Paulo is still the greatest producer, with an area of 3,610 hectares dedicated to Japanese persimmon culture in 2003; cf. [1]
  4. ^ A model experiment for de-astringency of persimmon fruit with high carbon dioxide treatment: in vitro gelation of kaki-tannin by reacting with acetaldehyde. Matsuo T and Itoo S, Agricultural and Biological Chemistry, 1982, 46(3), pages 683-689
  5. ^ Crain, Liz (2006-11-03). "Whether Asian or American, persimmons will grow on you". The Portland Tribune. Retrieved 2009-10-19. 
  6. ^ "Persimmon Fruit Facts". California Rare Fruit Growers, Inc.,. Retrieved 2007-01-15. 
  7. ^ Zhou et al., Carotenoids in Fruits of Different Persimmon Cultivars; Molecules. 2011, 16, 624-636; doi:10.3390/molecules16010624 Table 3.
  8. ^ Effect of five triterpenoid compounds isolated from leaves of Diospyroskaki on stimulus-induced superoxide generation and tyrosyl phosphorylation in human polymorphonuclear leukocytes. Guang Chen, Huangwei Lu, Chunlei Wang, Koichi Yamashita, Masanobu Manabe, Suixu Xu and Hiroyuki Kodama, Clinica Chimica Acta, June 2002, Volume 320, Issues 1–2, Pages 11–16, doi:10.1016/S0009-8981(02)00021-9