Apple is the fruit of the apple tree, cultivated everywhere in the world. Round, sometimes flattened at the top, it has a more or less tender skin, red, green or yellow according to the many varieties. It covers a crunchy, sweet and more or less acidic flesh. In the center, there are five hard alveoli containing two seeds.
Apple is the third most consumed fruit in the world, after citrus and banana. Seventy million tons are produced mainly by United States, China, Germany, France, Russia, Poland, Turkey, Iran and India. In all these countries, apples are also transformed and exported.
The story of apple
The apple tree is probably from a vast region which goes from Caucasus to the Tian Shan mountains on the edge of China. In this region still survive Malus sieversii colonies, one of the wild ancestors of cultivated apple trees and crabapples species. However, the apple fruit which we consume today is a hybrid which does not spontaneously grow in the wild. It would have started to spread 8,000 years before our era, along with merchants and travelers on primitive roads created for trade needs. Apple remnants dating back thousands of years have been found during excavations in Jericho, in Jordan Valley.
Greek philosopher Theophrastus described 6 varieties of apple trees, three hundred years before our era. He also gave advice how to care and graft techniques to multiply the trees. At the time people already knew that trees coming from direct sowing (seeds) gave fruits with lower quality than grafted trees. The Romans, who excelled in its culture, spread apple trees throughout the Empire, including in British Isles. In the first century of our era, thirty varieties were well known.
Today, there are a few thousand varieties worldwide, although 90% of the world production comes from a dozen varieties. Over the centuries, people have selected varieties which were better suited for consumption as fresh fruit, others were better to cook and others finally for making juice and cider. The fruits of some varieties are stored only a few days, while others can spend the winter without problem. There are also varieties whose fruit dries well and others varieties are more suitable for freezing.
Health benefits of apple
Apples are a good source of antioxidants and dietary fiber whether they are red, green or yellow. Eating apples regularly would reduce the risk of asthma, cancer and cardiovascular disease.
Benefits of apple
• Cardiovascular disease. Antioxidant power of apple would help reduce the risk of cardiovascular disease. Indeed, the antioxidants contained in the apple help to reduce and prevent lipid oxidation circulating in the blood and reduce blood cholesterol levels. According to a recent study, consumption of fresh apple can also reduce the incidence of acute coronary syndrome (ACS), particularly among men. This syndrome includes unstable angina and myocardial infarction.
• High cholesterol. Apple pectin would have a beneficial effects for lower blood cholesterol. Among rats, pectin would eliminate a lot of cholesterol by the stool. Moreover, studies among humans have shown that pectin consumption from apple and other soluble fibers, in this case the guar gum and arabic gum, caused a decline in blood cholesterol, especially the bad cholesterol. Apple juice would have beneficial effects on lipid profile and certain inflammatory markers. In particular, the apple juice flavonoids have these antioxidants and anti-inflammatories effects.
• Asthma. Eating apples (ideally 2 or more per week) would have a favorable effect on the respiratory function as well as on asthma incidence and affections of the respiratory tracts. Apple contains polyphenols and flavonoids. These might increase the body’s antioxidant ability and thus reducing the inflammatory response among asthmatics. On the other hand, other studies will be necessary before saying with certainty that they have a protective effect. Moreover, a study conducted among more than 2,600 children from 5 to 10 years old concluded that daily consumption of concentrated apple juice was associated with a lower incidence of wheezing respiratory noise (the most common symptom of asthma and can be an indicator of the disease). Finally, apple consumption during pregnancy could reduce the risk of asthma among children.
• Cancers. Several studies have shown that regular consumption of apples could reduce the risk of cancer, especially lung cancer and colorectal cancer. In vitro studies on cell cultures and in vivo studies among animals indicate that regular consumption of apple juice or an apple or more per day would have a preventive effect against colorectal, colon, breast and lung cancers. Polyphenols and other compounds contained in apple and apple juice have antioxidant effects and would decrease the proliferation of cancer cells. However, these recent hypotheses must be validated for humans.
What contains apple?
Apple contains a large variety of antioxidants that are known to prevent the oxidation of DNA and the proliferation of cancer cells, to reduce blood cholesterol levels and improve respiratory function. Apple contains flavonoids, such as quercepin, procyanidins, catechin and epicatechin, as well as other phenolic compounds, for example chlorogenic acid.
Quercetin is a powerful antioxidant, and it would have a potential of protection even against cancer and cardiovascular disease. According to researchers, quercetin contained in apple would contribute to a protective effect against lung cancer. Procyanidins, epicatechin and catechin, have been associated with a decrease in the oxidation of ‘bad’ cholesterol (LDL). Procyanidins are effective for the prevention of cancer cell development.
Polyphenols contained in apples have shown beneficial effects on blood cholesterol and a reduction in blood vessels lesions among animals. In a study among humans, daily consumption for 12 weeks of polyphenol capsules (600 mg) extracted from apples decreased LDL cholesterol and visceral fat. A fresh apple contains about 200 mg of polyphenols.
Pectin is a type of soluble fiber. It has the property to form a gel, which in part gives texture to jams and fruit jellies. It represents about half of total fiber quantity in an apple, especially in the skin (an apple contains about 1 g of pectin). By their ability to form a gel, soluble fiber may bind, in part, sugar and cholesterol in the intestine and thus reduce absorption.
Eating the peel of the apple is recommended
To enjoy the benefits of apple, it is best to eat the fruit with its peel. Indeed, the antioxidant power of apple skin is 2 to 6 times higher than the flesh. The skin would contain also 2 to 6 times more phenolic compounds and 2 to 3 times more flavonoids than flesh. This antioxidant capacity is among other things related to anthocyanins, the pigments that give the red color to the apple skin, but also several other flavonoids and phenolic compounds present in the peel. Another study established that apples with the skin are more effective to reduce the proliferation of cancer cells than apples without peel. Finally, apple peel contains a type of compound that is not in the flesh. This is the triterpenes (the most abundant being ursolique acid) which would have the property to prevent tumor growth.
Apple contains fructose and sorbitol, two types of sugars which can cause gastrointestinal discomfort (bloating, gas, diarrhea) among sensitive people. Among adults, these discomforts can be felt from 10 g of sorbitol per day. A portion of 50 g or more of fructose per day can also cause diarrhea. Note that 1 cup (250 ml) of apple juice contains 6 times more sorbitol (2.6 g) than a fresh apple (0.4 g). However, the difference is smaller with respect to fructose. A cup of apple juice contains 14.2 g and an apple 8.2 g.
A recent study conducted among children of 5 months showed that babies with colic tolerated less apple juice than grape juice. The latter contains no sorbitol and has the same amount of fructose and glucose. Apple juice contains almost 3 times more fructose than glucose. The researchers therefore concluded that it would be preferable, among children with colic, to moderate consumption of juice containing sorbitol and more fructose to glucose, like apple juice.
Selection and conservation
You can buy apples year-round. The best time to buy apple is during autumn because they are ripened on the tree. You can go pick them yourself at the farmer or you can buy them at the supermarket. The fruit must be kept tightly closed. Note that although fruit from organic farming is often less attractive, its taste is mostly very good.
Refrigerator. Always keep the apples in cool storage and never at room temperature because they continue to ripen and eventually lose some of their flavor. Put them in the vegetables drawer of the refrigerator, preferably in a perforated bag.
Dehydrator. It’s relatively easy to dry apples. First remove the heart, peel them, then cut into slices, sprinkle with lemon juice and place in an oven set on very low heat for 6 to 8 hours or the dehydrator. You can also put the washers on a string and hang them out to dry in the air, which takes a few weeks.
Freezer. When they are fresh, only freeze apples with firm flesh. Remove the heart, cut into slices and place them in bags to freeze. You can also freeze them baked, stewed or in pieces.
The apple tree grows best in temperate climates. It requires a deep ground, well drained, rich in breeding ground. It’s preferable to choose a place with a slope to avoid frost pockets and preserve flowers in the late spring frosts.
• pH: 6 to 7.
• Choose 2 or 3 varieties flowering at the same time to ensure good pollination. Some varieties of crab trees can serve as pollinators. If you have a small space you can plant dwarf varieties. Choose one of the new cultivars resistant to speckle (a fungal disease which attacks fruit trees).
• Plant as soon as possible in the spring when the trees are still in winter condition. Before planting, soak the roots a few hours in a water and clay solution.
• Prune trees from their installation and repeat it every year.
• Thin the fruits to keep only one per branch.
• Before the bud burst, apply dormant oil (repellent product slathered on the trunk when the tree is in a dormant period) to clear off insects, including mites.
• Against apple maggot, hang 3 or 4 pheromone traps per tree. Against the codling moth, spray a solution of Bacillus thurigensis. On tree varieties prone to speckle, treat several times during the season with sulfur in order to limit infestation. However, you should not worry if there’s some black spots on the fruit.
Ecology and environment
More and more traditional growers rely on integrated fruit production concept. It is intended to protect apple trees by considering all steps of production, implementation of the orchard until harvest. It allows using synthetic pesticides as a last resort.
In organic farming, where chemical products are strictly forbidden, you can find a spray product to protect vegetable productions against some insects and diseases. Products made from clay to protect apple trees against insects exist. It was particularly effective against the plum curculio which is also found in apple trees and apple codling moth. In organic orchards where it has been experienced, the product had preserved nearly 80% of the fruit against insect’s attacks while without it, 80% of fruits were affected. In fact, the product does not destroy the insect, but creates a barrier upsetting it and keep it away.
Kaolin also prevents appearance of certain fungal diseases which, without harming the quality of the fruit, may harm the fruit appearance. Finally, researchers who feared that clay adversely affect photosynthesis realized that was not the case, but it protected the leaves against infrared rays and heat. These products are already used by farmers for a multitude of crops: fruit with core and seeds, citrus fruits, oilseeds, berries, grapes, fruits vegetables, onions and their relatives, cabbages, cotton, cereals, as well as for ornamental plants.