Diospyros kaki, better known as the Japanese persimmon, kaki persimmon (kaki) 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, 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, and numerous cultivars have been selected. A variety is Diospyros kaki var. sylvestris Makino. When ripe, this fruit comprises thick pulpy jelly encased in a waxy thin-skinned shell.
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. The tannin levels are reduced as the fruit matures. It is not edible in its crisp, firm state; it tastes best 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. Other 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.
"Sharon Fruit" (named originally after Sharon plain in Israel) is the trade name for D. kaki fruit whose astringency has been chemically removed. It is also known as the "Korean mango".
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).
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.
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.