Lemon peel, Limonis Fructus, Limonis Cortex
Lemon is the fruit of Citrus limon (L.) Burm., a small tree of the family Rutaceae.
Lemons are widely cultivated in many countries of the world including Africa, the Mediterranean countries, Australia, many European and North and South American countries.
Macroscopical and Microscopical characters
The whole fruit is ovoid or obovoid in shape, 6 to 10 cm long, 4 to 7 cm wide with a nipple-shaped apex. It has 8 to 10 loculi, each of which is completely filled with juice filled small outgrowths from the inner epidermis of the outer pericarp wall and from the placenta. The pulp has an agreeable strongly acidulous taste. The lemon peel occurs in small strips, about 2 cm wide and 3 mm thick, upper surface pale yellow and rough with numerous large oil glands immediately below the narrow epidermis. It possesses a strong characteristic odour and an aromatic bitter taste. Fresh lemons yield about 30 percent of juice, which is a turbid yellowish liquid with an appealing odour and acid taste.
The constituents of the lemon peel include volatile oil, hesperidin and vitamin B. The chief constituent of the Juice is 6 to 9 percent citric acid and also Vitamin C.
Lemon oil, extracted from the fruit-peel, is used as a flavoring agent in syrups and suspensions. The Juice of the fresh fruit is used as a source of citric acid and Vitamin C concentrates.