THE AMAZING ROSELLE

SCIENTIFIC NAME: Hibiscus sabdariffa
FAMILY: Malvaceae

The true roselle, Hibiscus sabdariffa, is of two main types. The more important, economically, is altissima, an erect, sparsely-branched annual to 16' high, which is cultivated for its jute-like fiber in India, the East Indies, Nigeria and to some extent, in tropical America. The other distinct type, Hibiscus sabdariffa , is the one that we are most interested in and embraces shorter bushy forms which have been described as races. One of the four races has inedible calyces; two have green/yellow edible calyces and also yield fiber, but the one we are most interested in is the race "Ruber" and its named cultivars with edible red calyces, or the green-fruited strain belonging to the race "Albus".

The Hibiscus sabdariffa ruber is an annual erect, bushy, herbaceous shrub to 8' tall with smoother, cylindrical, red stems. The leaves are alternate, 3-5" long, green with reddish veins, deeply three-, five- or even seven-lobed. The flowers, borne singly in the leaf axils, are up to 4" wide, yellow with a rose or maroon eye that turns pink as they wither at the end of the day. The calyx, consisting of 5 large sepals with a collar of 8 to 12 slim, pointed bracts around the base, begins to enlarge, becomes fleshy, crisp and juicy, 1¼"-2¼" long, fully encloses the velvety seed capsule, which is green when immature, 5-podded, with each pod containing 3 to 4 kidney-shaped, light brown seeds. The capsule turns brown and splits open when mature and dry. The calyx, stems and leaves are acid and closely resemble the cranberry, Vaccinium species, in flavour.

A minor ornamental in Florida is the red leafed hibiscus, Hibiscus acetosella, of tropical Africa which has red stems, red or bronze leaves and red-striped yellow flowers with a dark red eye. This plant has often been confused with roselle, though its calyx is not fleshy and only the young leaves are used for culinary purposes, usually cooked with rice or vegetables because of their acid flavor. The roselle is native from India to Malaysia and must have been carried at an early date to Africa. It has become widely distributed in the tropics and subtropics of both hemispheres, and in many areas of the West Indies and Central America has become naturalized. Seeds are said to have been brought to the New World by African slaves. Roselle was grown in Brazil in the 17th century and Jamaica in 1707 and by the turn of the century was being cultivated for food use in Guatemala and Mexico, at which time factories were producing roselle jam in Australia and exporting considerable quantities to Europe. At about the same time, seeds were brought into California and Hawaii and into Florida. It received much publicity in southern Florida as a substitute for cranberries. The roselle is still produced in large quantities in Central America and in the Philippines. Today, roselle is attracting attention of food and beverage manufacturers and pharmaceutical concerns who feel it may have exploitable possibilities as a natural fruit product and as a colorant to replace some synthetic dyes.

In 1971 it was reported that roselle calyxes produced and dried in Senegal were being shipped to Europe (Germany, Switzerland, France and Italy) at a rate of 10 to 25 tons annually.

After World War 2, the roselle lost popularity in Florida and gradually declined as a home-grown plant until about 1980 when a resurgence of interest began to be noticed.

The roselle is very sensitive to frost and succeeds best in tropical and subtropical regions, from sea level up to 3000 feet with a rainfall of about 70" during its growing season. Deep, fertile, sandy loam is the preferable soil for roselles, but they will grow and produce well in almost any soil including our sandy soil in central Florida and the limestone soil in Dade County. In some locations in southern Florida the plants have re-seeded themselves and have spread so extensively they have become a nuisance.

The roselle is usually propagated by seed and grows readily from cuttings, but the yield from cuttings is relatively low. The roselle is a short-day plant and photo-periodic. The ideal planting time for production of calyxes is mid-May. Blooming will occur in September and October and calyces will be ready to harvest in November and December. Harvesting causes latent buds to develop and extends the flowering life of the plant to late February. However if the fruit is not gathered, but left to mature, the plants will die in January. A 4-6-8 fertilizer is recommended because an excess of ammonia encourages vegetative growth and reduces fruit production. The fruit of the roselle ripen progressively from the lowest to the highest limbs. Harvesting should occur when the fruit are full grown but still tender, and at this stage are easily snapped off by hand. They are easier to break off in the morning than at the end of the day. The roselle fruit is prepared for use by washing, then stripping the calyx from the seed pod. They may be chopped and added to fruit salad. In Africa, they are frequently cooked as a side dish eaten with ground up peanuts, for stewing as sauce or filling for tarts or pies; they may be left intact if tender and cooked with sugar. The product will be almost indistinguishable from cranberry sauce in taste and appearance. For making a finer texture of sauce or juice, syrup, jam, marmalade, relish, chutney or jelly, the calyx may be first chopped in a bowl or passed through a meat grinder, or the calyx, after cooking, may be pressed through a sieve. Some cooks steam the roselle with a little water until soft before adding the sugar, then boil for 15 minutes.

Roselle sauce or syrup may be added to puddings, cake frosting, gelatine and salad dressings; also as a topping for gingerbread, pancakes, waffles or ice cream. It is not necessary to add pectin to make a firm jelly. In fact, the calyxes possess 3.2% pectin. In Pakistan, roselle has been recommended as a source of pectin for fruit-preserving industry. The juices made by cooking a quantity of calyx with one quarter of water in ratio to amount of calyxes is used for cold drinks and may be frozen or bottled if not for immediate need. A lemonade-like beverage made from the calyxes is still one of the most popular summer drinks in Mexico. In Egypt roselle-ade is consumed cold in summer, hot in winter. Also the juice makes a very colorful wine.

Calyxes are either frozen or dried in the sun or artificially for out-of-season supply, marketing or export. In Mexico today, the dried calyxes are packed for sale in imprinted plastic bags.

For retailing in Africa, dried roselle is pressed into solid cakes or balls. In Senegal, the dried calyxes are squeezed into great balls weighing up to 175 lbs for shipment to Europe where they are utilized to make extract for flavouring liqueur, In the U.S. , the Food and Drug Administration regulations permit the use of the extract in alcoholic beverages. The young leaves and tender stems of roselle are eaten raw in salads or cooked as greens alone or in combination with other vegetables or with meat or fish. They are also added to curries as seasonings. The leaves of green roselle are marketed in large quantities in West Africa.

The juice of the boiled and strained leaves and stems is utilized for the same purpose as the juice extracted from the calyx. The herbage is most utilized in the fresh state in the Philippines. The seeds are somewhat bitter, but have been ground to a meal for human food in Africa and have also been roasted as a substitute for coffee. The residue remaining after extraction of oil by parching, soaking in water containing ashes for 3 or 4 days and then pounding the seeds or by crushing and boiling them, is eaten in soup or blended with bean meal in patties. It is high in protein, The seed is considered excellent feed for chickens. The residue after oil extraction is valued as cattle feed when available in quantity.

In India, Africa, and Mexico, all the above-ground parts of the roselle plant are valued in native medicine. Infusions of the leaves or calyxes are regarded as diuretic, cholerectic and hypotensive and decreasing the viscosity of the blood. In Senegal, roselle extract is used for lowering blood pressure. In 1962, the calyxes were found to be anti-spasmodic and anthelmintic and anti-bacterial as well. In 1964, the aqueous extract was found effective against a poultry disease. Three years later, an extract of the calyx was found to be lethal to Mycobacterium tuberculosis. In Guatemala, roselle-ade is a favourite for the after-effects of drunkenness. In East Africa, the calyx infusion called "Sudan tea" is taken to relieve coughs. Roselle juice with salt, pepper, asafetida and molasses is taken as a remedy for biliousness. The heated leaves are applied to cracks in the feet and on boils and ulcers to speed maturation. A lotion made from leaves is used on sores and wounds. The seeds are said to be diuretic and tonic in action and the brownish-yellow seed oil is claimed to heal sores on camels. In India, a decoction of the seeds is given to relieve dysuria, strangury and mild cases of dyspepsia and debllity. Brazilians attribute stomachic, emollient and resolutive properties to the bitter roots. The calyx is high in calcium, niacin, riboflavin and iron.

Article RFCI Tampa Bay Chapter July and Aug. 1992

DATE: September 1992

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