The apple is the pomaceous fruit of the apple tree, species Malus domestica in the rose family (Rosaceae). It is one of the most widely cultivated tree fruits, and the most widely known of the many members of genus Malus that are used by humans.
The tree originated in Western Asia, where its wild ancestor, the Alma, is still found today. There are more than 7,500 known cultivars of apples, resulting in a range of desired characteristics. Cultivars vary in their yield and the ultimate size of the tree, even when grown on the same rootstock.
At least 55 million tonnes of apples were grown worldwide in 2005, with a value of about $10 billion. China produced about 35% of this total. The United States is the second-leading producer, with more than 7.5% of world production. Iran is third, followed by Turkey, Russia, Italy and India.
The apple forms a tree that is small and deciduous, reaching 3 to 12 metres (9.8 to 39 ft) tall, with a broad, often densely twiggy crown.The leaves are alternately arranged simple ovals 5 to 12 cm long and 3–6 centimetres (1.2–2.4 in) broad on a 2 to 5 centimetres (0.79 to 2.0 in) petiole with an acute tip, serrated margin and a slightly downy underside. Blossoms are produced in spring simultaneously with the budding of the leaves. The flowers are white with a pink tinge that gradually fades, five petaled, and 2.5 to 3.5 centimetres (0.98 to 1.4 in) in diameter. The fruit matures in autumn, and is typically 5 to 9 centimetres (2.0 to 3.5 in) in diameter. The center of the fruit contains five carpels arranged in a five-point star, each carpel containing one to three seeds, called pips.
Health benefits
The proverb “An apple a day keeps the doctor away.”, addressing the health effects of the fruit, dates from 19th century Wales. Research suggests that apples may reduce the risk of colon cancer, prostate cancer and lung cancer. Compared to many other fruits and vegetables, apples contain relatively low amounts of vitamin C, but are a rich source of other antioxidant compounds. The fiber content, while less than in most other fruits, helps regulate bowel movements and may thus reduce the risk of colon cancer. They may also help with heart disease, weight loss, and controlling cholesterol. The fiber contained in apples reduces cholesterol by preventing reabsorption, and (like most fruits and vegetables) they are bulky for their caloric content.
There is evidence that in vitro apples possess phenolic compounds which may be cancer-protective and demonstrate antioxidant activity. The predominant phenolic phytochemicals in apples are quercetin, epicatechin, and procyanidin B2.
Apple juice concentrate has been found to increase the production of the neurotransmitter acetylcholine in mice, providing a potential mechanism for the “prevention of the decline in cognitive performance that accompanies dietary and genetic deficiencies and aging.” Other studies have shown an “alleviation of oxidative damage and cognitive decline” in mice after the administration of apple juice. Researchers at the Chinese University of Hong Kong discovered that fruit flies who were fed an apple extract lived 10% longer than other flies who were fed a normal diet. However, apple seeds are mildly poisonous, containing a small amount of amygdalin, a cyanogenic glycoside; it usually is not enough to be dangerous to humans, but can deter birds.
Apple allergy
Oral allergy syndrome is an allergic reaction some people will experience due to the birch pollen left on the apples.Because the pollen is the main irritant, only the raw apples, especially their skin, cause the allergic reaction. Cooked apples do not cause these symptoms as the heat denatures the proteins in the pollen, rendering them harmless to those sensitive. If one is allergic to apples, he or she may also experience an allergic reaction with other fruits in the Rosaceae family, such as peaches.
Symptoms
Symptoms vary from person to person but are generally mild. This typically includes the sensation of itching and swelling around the mouth and lips. Other symptoms include watery eyes, runny nose and sneezing. Hives may develop in those who have a high sensitivity to the pollen. Abdominal pain and diarrhea may also occur.