Healthy Food - Lemon and Lime

Healthy Food - Lemon and Lime. The lemon (Citrus × limon) is a small evergreen tree native to Asia. The tree's ellipsoidal yellow fruit is used for culinary and non-culinary purposes throughout the world, primarily for its juice, though the pulp and rind (zest) are also used in cooking and baking. The juice of the lemon is about 5% to 6% citric acid, which gives lemons a sour taste. The distinctive sour taste of lemon juice makes it a key ingredient in drinks and foods such as lemonade.

Lime (from Arabic and French lim) is a term referring to a citrus fruit which is typically round, green, 3–6 centimetres (1.2–2.4 in) in diameter, and containing sour (acidic) pulp. There are several species of citrus trees whose fruits are called limes, including the Key lime, Persian lime, kaffir lime, and desert lime. Limes are a good source of vitamin C, and are often used to accent the flavours of foods and beverages. They are grown year-round and are usually smaller and less sour than lemons, although varieties may differ in sugar and acidic content.

Although lemons and limes may not be what you would choose for an afternoon snack, we consider them as powerhouses when we want to bring out the flavor of other foods. While both are available throughout the year, lemons are in the peak of their season around May, June and August while limes are at their peak from May through October.

Lemons are oval in shape and feature a yellow, texturized outer peel. Like other citrus fruits, their inner flesh is encased in eight to ten segments.

Usually smaller than lemons, limes are oval or round in shape having a diameter of one to two inches with green flesh and skin. They can be either sour or sweet depending on the variety; however, sweet limes are not readily available in the United States. Sour limes contain citric acid giving them an acidic and tart taste, while sweet limes lack citric acid and are sweeter in flavor.

Description

Lemons

Lemons, scientifically known as Citrus limon, are more commonly known as the fruit that evokes images of sunshine and the sweet smiles of children standing roadside at their homemade lemonade stands.

Lemons are oval in shape and feature a yellow, texturized outer peel. Like other citrus fruits, their inner flesh is encased in segments, with the average lemon having eight to ten.

While most lemons are tart, acidic and astringent, they are also surprisingly refreshing. The two main types of sour lemons are the Eureka and the Lisbon. The Eureka generally has more texturized skin, a short neck at one end and a few seeds, while the Lisbon has smoother skin, no neck and is generally seedless. In addition to these sour lemons, there are also some varieties that are sweet in flavor. One notable example is the Meyer lemon that is becoming more popular in both markets and restaurants.

Limes

 Limes are a small citrus fruit, Citrus aurantifolia, whose skin and flesh are green in color and which have an oval or round shape with a diameter between one to two inches. Limes can either be sour or sweet, with the latter not readily available in the United States. Sour limes possess a greater sugar and citric acid content than lemons and feature an acidic and tart taste, while sweet limes lack citric acid content and are sweet in flavor.

There are two general varieties of sour limes available, the Tahitian and the Key. Among Tahitian limes are the egg-shaped Persian and the smaller, seedless Bearss. Key limes, famous for the pie bearing their name, are smaller and more acidic than the Tahitian variety.

History

Lemons

Lemons were originally developed as a cross between the lime and the citron and are thought to have originated in China or India, having been cultivated in these regions for about 2,500 years. Their first introduction to Europe was by Arabs who brought them to Spain in the 11th century around the same time that they were introduced into Northern Africa. The Crusaders, who found the fruit growing in Palestine, are credited with bringing the lemon to other countries across Europe. Like many other fruits and vegetables, lemons were brought to the Americas by Christopher Columbus in his second voyage to the New World in 1493, and have been grown in Florida since the 16th century.

Lemons, like other vitamin-C rich fruits, were highly prized by the miners and developers during the California Gold Rush in the mid-19th century, since they were used to protect against the development of scurvy. They were in such demand that people were willing to pay up to $1 per lemon, a price that would still be considered costly today and was extremely expensive back in 1849. The major producers of lemons today are the United States, Italy, Spain, Greece, Israel and Turkey. Healthy Food - Lemon and Lime.

Limes

Limes are grown on trees that flourish in tropical and subtropical climates. They were thought to originate in Southeast Asia. Arab traders brought lime trees back from their journey to Asia and introduced them into Egypt and Northern Africa around the 10th century. The Arabian Moors brought them to Spain in the 13th century and then, like many fruits, they were spread throughout southern Europe during the Crusades.

Limes made their way to the New World with Columbus on his second voyage in 1493, and were subsequently planted in many Caribbean countries whose hot, humid climates supported the cultivation of this fruit. Centuries later, British explorers and traders, who were readily using the vitamin C-rich limes that grew in their West Indies colonies to prevent scurvy, earned the nickname "limey," a word that is often still used colloquially for persons of British descent.

The introduction of limes to the United States began in the 16th century when Spanish Explorers brought the West Indies lime to the Florida Keys, beginning the advent of Key limes. In the following century, Spanish missionaries attempted to plant lime trees in California, but the climate did not support their growth. In great demand by the miners and explorers during the California Gold Rush as a fruit that was known to prevent scurvy, limes began to be imported from Tahiti and Mexico at this time in the mid-19th century. Today, Brazil, Mexico and the United States are among the leading commercial producers of limes.

Varieties

• The 'Bonnie Brae' is oblong, smooth, thin-skinned, and seedless; mostly grown in San Diego County.
• The bush lemon tree, a naturalized lemon, grows wild in subtropical Australia. It is very hardy, and has a thick skin with a true lemon flavor; the zest is good for cooking. It grows to about 4 m in sunny locations.[citation needed]
• The 'Eureka' grows year-round and abundantly. This is the common supermarket lemon, also known as 'Four Seasons' (Quatre Saisons) because of its ability to produce fruit and flowers together throughout the year. This variety is also available as a plant to domestic customers.
• The 'Femminello St. Teresa', or 'Sorrento' is native to Italy. This fruit's zest is high in lemon oils. It is the variety traditionally used in the making of limoncello.
• The 'Jhambiri' (C. jhambiri), also known as rough lemon and bush lemon, has a rough skin, lemon-yellow exterior, and very sour pulp. It is widely used as a rootstock in South Asia.
• The 'Lisbon' is a good-quality bitter lemon with high juice and acid levels; the fruits of Lisbon are very similar to Eureka. The vigorous and productive trees are very thorny, particularly when young.
• The 'Meyer' is a cross between a lemon and possibly an orange or a mandarin, and was named after Frank N. Meyer, who first discovered it in 1908. Thin-skinned and slightly less acidic than the Lisbon and Eureka lemons, Meyer lemons require more care when shipping and are not widely grown on a commercial basis. Meyer lemons have a much thinner rind, and often mature to a yellow-orange color. They are slightly more frost-tolerant than other lemons.
• The 'Ponderosa' is more cold-sensitive than true lemons; the fruit are thick-skinned and very large. It is likely a citron-lemon hybrid.
• The 'Variegated Pink' is a varietal of the 'Eureka' or 'Lisbon' cultivars with variegated patterns in the foliage and the rinds of immature green fruit. Upon maturing to yellow, the variegated pattern recedes in the fruit rind. The flesh and juice are pink or pinkish-orange instead of yellow.[citation needed]
• The 'Verna' is a Spanish variety of unknown origin.
• The 'Yen Ben' is an Australasian cultivar.

Health Benefits

Limonins Support Optimal Health
In animal studies and laboratory tests with human cells, compounds in citrus fruits, including lemons and limes, called limonoids have been shown to help fight cancers of the mouth, skin, lung, breast, stomach and colon. Now, scientists from the US Agricultural Research Service (ARS) have shown that our bodies can readily absorb and utilize a very long-acting limonoid called limonin that is present is citrus fruits in about the same amount as vitamin C.

In citrus fruits, limonin is present in the form of limonin glucoside, in which limonin is attached to a sugar (glucose) molecule. Our bodies easily digest this compound, cleaving off the sugar and releasing limonin. Healthy Food - Lemon and Lime

In the ARS study, 16 volunteers were given a dose of limonin glucoside in amounts ranging from those that would be found in from 1 to 7 glasses of orange juice. Blood tests showed that limonin was present in the plasma of all except one of the subjects, with concentrations highest within 6 hours after consumption. Traces of limonin were still present in 5 of the volunteers 24 hours after consumption!

Limonin's bioavailability and persistence may help explain why citrus limonoids are potent anti-carcinogens that may prevent cancerous cells from proliferating. Other natural anti-carcinogens are available for much less time; for example, the phenols in green tea and chocolate remain active in the body for just 4 to 6 hours.

The ARS team are now investigating the potential cholesterol-lowering effects of limonin. Lab tests indicate that human liver cells produce less apo B when exposed to limonin. Apo B is a structural protein that is part of the LDL cholesterol molecule and is needed for LDL production, transport and binding, so higher levels of apo B translate to higher levels of LDL cholesterol.

Phytonutrients with Antioxidant and Antibiotic Effects
Like many of the fruits and vegetables featured on our website, lemons and limes contain unique flavonoid compounds that have antioxidant and anti-cancer properties. Of special interest in limes have been flavonoids called flavonol glycosides, including many kaempferol-related molecules. While these flavonoids have been shown to stop cell division in many cancer cell lines, they are perhaps most interesting for their antibiotic effects. In several villages in West Africa where cholera epidemics had occurred, the inclusion of lime juice during the main meal of the day was determined to have been protective against the contraction of cholera. (Cholera is a disease triggered by activity of the bacteria called Vibrio cholera). Researchers quickly began to experiment with the addition of lime juice to the sauce eaten with rice, and in this role, lime juice was also found to have a strong protective effect against cholera.

Several other fascinating research studies on the healing properties of lemons and limes have shown that cell cycles including the decision a cell makes about whether to divide (called mitosis) or die (apoptosis are altered by lime juice, as are the activities of special immune cells called monocytes.

In addition to their unique phytonutrient properties, lemons and limes are an excellent source of vitamin C, one of the most important antioxidants in nature. Vitamin C is one of the main antioxidants found in food and the primary water-soluble antioxidant in the body. Vitamin C travels through the body neutralizing any free radicals with which it comes into contact in the aqueous environments in the body both inside and outside cells. Free radicals can interact with the healthy cells of the body, damaging them and their membranes, and also cause a lot of inflammation, or painful swelling, in the body. This is one of the reasons that vitamin C has been shown to be helpful for reducing some of the symptoms of osteoarthritis and rheumatoid arthritis.

Since free radicals can damage blood vessels and can change cholesterol to make it more likely to build up in artery walls, vitamin C can be helpful for preventing the development and progression of atherosclerosis and diabetic heart disease.

Vitamin C is also vital to the function of a strong immune system. The immune system's main goal is to protect you from illness, so a little extra vitamin C may be useful in conditions like colds, flus, and recurrent ear infections.

Owing to the multitude of vitamin C's health benefits, it is not surprising that research has shown that consumption of vegetables and fruits high in this nutrient is associated with a reduced risk of death from all causes including heart disease, stroke and cancer.

Protection against Rheumatoid Arthritis
While one study suggests that high doses of supplemental vitamin C makes osteoarthritis, a type of degenerative arthritis that occurs with aging, worse in laboratory animals, another indicates that vitamin C-rich foods, such as lemons and limes, provide humans with protection against inflammatory polyarthritis, a form of rheumatoid arthritis involving two or more joints.

The findings, presented in the Annals of the Rheumatic Diseases were drawn from a study of more than 20,000 subjects who kept diet diaries and were arthritis-free when the study began, and focused on subjects who developed inflammatory polyarthritis and similar subjects who remained arthritis-free during the follow-up period. Subjects who consumed the lowest amounts of vitamin C-rich foods were more than three times more likely to develop arthritis than those who consumed the highest amounts.

How to Select and Store

Lemons
One of the tricks to finding a good quality lemon is to find one that is rather thin-skinned since those with thicker peels will have less flesh and therefore be less juicy. Therefore, choose lemons that are heavy for their size and that feature peels that have a finely grained texture. They should be fully yellow in color as those that have green tinges will be more acidic due to the fact that they have not fully ripened. Signs of overmature fruit include wrinkling, soft or hard patches and dull coloring. Fresh lemons are available all year round.

Lemons will stay fresh kept at room temperature, away from exposure to sunlight, for about one week. If you will not be using them within this time period, you can store the lemons in the refrigerator crisper where they will keep for about four weeks.

Lemon juice and zest can also be stored for later use. Place freshly squeezed lemon juice in ice cube trays until frozen, subsequently storing them in plastic bags in the freezer. Dried lemon zest should be stored in a cool and dry place in an airtight glass container. Healthy Food - Lemon and Lime.

Limes
Choose limes that are firm and heavy for their size, free of decay and mold. They should have a glossy skin that is deep green in color; although limes turn more yellow as they ripen, they are at the height of their lively, tart flavor when they are green in color. While brown spots on the skin of limes may not affect their color, limes that are mostly brownish in color should be avoided since this may be an indication that they have "scald" which may cause them to have an undesirable moldy taste. Limes are available in the marketplace throughout the year, although they are usually in greater supply from mid-spring through mid-fall.

Limes can be kept out at room temperature where they will stay fresh for up to one week. Make sure to keep them away from sunlight exposure since it will cause them to turn yellow and will alter their flavor. Limes can be stored in the refrigerator crisper, wrapped in a loosely sealed plastic bag, where they will keep fresh for about 10-14 days. While they can be kept longer than that, for another several weeks, they will begin to lose their characteristic flavor.

Lime juice and zest can also be stored for later use. Place freshly squeezed lime juice in ice cube trays until frozen, subsequently storing them in plastic bags in the freezer. Dried lime zest should be stored in a cool and dry place in an airtight glass container.

Culinary uses

Lemons

Lemon juice, rind, and zest are used in a wide variety of foods and drinks. Lemon juice is used to make lemonade, soft drinks, and cocktails. It is used in marinades for fish, where its acid neutralizes amines in fish by converting them into nonvolatile ammonium salts, and meat, where the acid partially hydrolyzes tough collagen fibers, tenderizing the meat, but the low pH denatures the proteins, causing them to dry out when cooked. Lemon juice is frequently used in the United Kingdom to add to pancakes, especially on Shrove Tuesday.

Lemon juice is also used as a short-term preservative on certain foods that tend to oxidize and turn brown after being sliced (enzymatic browning), such as apples, bananas, and avocados, where its acid denatures the enzymes.

Lemon juice and rind are used to make marmalade and lemon liqueur. Lemon slices and lemon rind are used as a garnish for food and drinks. Lemon zest, the grated outer rind of the fruit, is used to add flavor to baked goods, puddings, rice, and other dishes.

Preserved lemons are a part of Moroccan cuisine. They are also one of the main ingredients in many Indian cuisines. Either lemon pickle or mango pickle is part of everyday lunches in Southern India.

The leaves of the lemon tree are used to make a tea and for preparing cooked meats and seafoods.

Limes

Lime juice may be squeezed from fresh limes, or purchased in bottles in both unsweetened and sweetened varieties. Lime juice is used to make limeade, and as an ingredient (typically as sour mix) in many cocktails.

Lime extracts and lime essential oils are frequently used in perfumes, cleaning products, and aromatherapy.

In India, the lime is used in Tantra for removing evil spirits. It is also combined with Indian chillies to make a protective charm to repel the evil eye. Furthermore, it was believed that hanging limes over sick people cured them of the illness by repelling evil spirits lurking inside the body. Lime pickles are an integral part of Indian Cuisine. South Indian cuisine is so heavily based on lime that having either lemon pickle or lime pickle is considered a must of Onam Sadhya.

Other uses

Industrial
Lemons were the primary commercial source of citric acid before the development of fermentation-based processes. Healthy Food - Lemon and Lime

As a cleaning agent
The juice of the lemon may be used for cleaning. A halved lemon dipped in salt or baking powder is used to brighten copper cookware. The acid dissolves the tarnish and the abrasives assist the cleaning. As a sanitary kitchen deodorizer the juice can deodorize, remove grease, bleach stains, and disinfect; when mixed with baking soda, it removes stains from plastic food storage containers. The oil of the lemon's peel also has various uses. It is used as a wood cleaner and polish, where its solvent property is employed to dissolve old wax, fingerprints, and grime. Lemon oil and orange oil are also used as a nontoxic insecticide treatment.

A halved lemon is used as a finger moistener for those counting large amounts of bills, such as tellers and cashiers.

Medicinal
Lemon oil may be used in aromatherapy. Lemon oil aroma does not influence the human immune system, but may enhance mood. The low pH of juice makes it antibacterial, and in India, the lemon is used in Indian traditional medicines (Siddha medicine and Ayurveda).[citation needed]

Other
One educational science experiment involves attaching electrodes to a lemon and using it as a battery to produce electricity. Although very low power, several lemon batteries can power a small digital watch.[19] These experiments also work with other fruits and vegetables. Lemon juice is also sometimes used as an acid in educational science experiments. Lemon juice may be used as a simple invisible ink, developed by heat.

Lemon alternatives
Many plants taste or smell similar to lemons.

• Certain cultivars of basil
• Cymbopogon (lemongrass)
• Lemon balm, a mint-like herbaceous perennial in the Lamiaceae family
• Two varieties of scented geranium: Pelargonium crispum (lemon geranium) and Pelargonium x melissinum (lemon balm)
• Lemon myrtle, an Australian bush food, has recently become a popular alternative to lemons.[20] The crushed and dried leaves and edible essential oils have a strong, sweet lemon taste, but contain no citric acid. Lemon myrtle is popular in foods that curdle with lemon juice, such as cheesecake and ice cream.
• Lemon thyme
• Lemon verbena
• Limes, another common sour citrus fruit, used similarly to lemons
• Certain cultivars of mint
• Magnolia grandiflora tree flowers
• Several cultivars of hybrid tea roses

Tips for Preparing and Cooking

Tips for Preparing Lemon and Limes

Lemons and limes are often called for in recipes in the form of juice. As they will produce more juice when warmer, always juice them when they are at room temperature or place them in a bowl of warm water for several minutes. Rolling them under the palm of your hand on a flat surface will also help to extract more juice.

Before cutting the lemon or lime in half horizontally through the center, wash the skin so that any dirt or bacteria residing on the surface will not be transferred to the fruit's interior. While you could remove any visible seeds before juicing the halves, you could also wait until after the process is complete, since there are bound to be some seeds that reside deeper and are not visible from the surface. The juice can then be extracted in a variety of ways. You can either use a juicer, reamer or do it the old fashioned way, squeezing by hand.

If your recipe calls for lemon or lime zest, make sure that you use fruit that is organically grown since most conventionally grown fruits will have pesticide residues on their skin. After washing and drying the lemon or lime, use a zester, paring knife or vegetable peeler to remove the zest, which is the colored part of the peel. Make sure not to remove too much of the peel as the white pith underneath is bitter and should not be used. The zest can then be more finely chopped or diced if necessary.

How to Enjoy

A Few Quick Serving Ideas
Place thinly sliced lemons, peel and all, underneath and around fish before cooking. Baking or broiling will soften the slices so that they can be eaten along with the fish.

Combine lemon juice with olive or flax oil, freshly crushed garlic and pepper to make a light and refreshing salad dressing.

If you are watching your salt intake (and even if you are not), serve lemon wedges with meals as their tartness makes a great salt substitute.

Combine freshly squeezed lime juice, evaporated cane juice and either plain or sparkling water to make limeade.

Add an-easy-to-prepare zing to dinner tonight by tossing seasoned cooked brown rice with garden peas, chicken pieces, scallions, pumpkin seeds, lime juice and lime zest.

Squeeze some lime juice onto an avocado quarter and eat as is.

In cooking, lime is valued both for the acidity of its juice and the floral aroma of its zest. It is a common ingredient in authentic Mexican, Vietnamese and Thai dishes. It is also used for its pickling properties in ceviche. Some guacamole recipes call for lime juice.

The use of dried limes (called black lime or loomi) as a flavouring is typical of Persian cuisine and Iraqi cuisine, as well as in Gulf-style baharat (a spice mixture that is also called kabsa or kebsa).

Lime is an essential ingredient of any cuisine from India, and many varieties of pickles are made, e.g. sweetened lime pickle, salted pickle, and lime chutney.

Lime leaves are also used as a herb in South, East, and Southeast Asia. Lime is frequently used to add flavour to cold and hot drinks, including water, tonic and other cocktails.

Key lime gives the character flavouring to the American dessert known as Key lime pie. In Australia, desert lime is used for making marmalade.

Cocktails

Lime is an essential ingredient in several highball cocktails, often based on gin, such as gin and tonic, the gimlet and the Rickey. Freshly squeezed lime juice is also considered a key ingredient in margaritas, although sometimes lemon juice is substituted.


Individual Concerns

Lemon and Lime Peels and Oxalates
The peels of lemons and limes are among a small number of foods that contain measurable amounts of oxalates, naturally-occurring substances found in plants, animals, and human beings. When oxalates become too concentrated in body fluids, they can crystallize and cause health problems. For this reason, individuals with already existing and untreated kidney or gallbladder problems may want to avoid eating lemon or lime peels. Laboratory studies have shown that oxalates may also interfere with absorption of calcium from the body. Yet, in every peer-reviewed research study we've seen, the ability of oxalates to lower calcium absorption is relatively small and definitely does not outweigh the ability of oxalate-containing foods to contribute calcium to the meal plan. If your digestive tract is healthy, and you do a good job of chewing and relaxing while you enjoy your meals, you will get significant benefits—including absorption of calcium—from calcium-rich foods plant foods that also contain oxalic acid. Ordinarily, a healthcare practitioner would not discourage a person focused on ensuring that they are meeting their calcium requirements from eating these nutrient-rich foods because of their oxalate content. For more on this subject, please see "Can you tell me what oxalates are and in which foods they can be found?"

Lemons and Limes and Wax Coatings
Conventionally grown lemons and limes may be waxed to protect them from bruising during shipping. Plant, insect, animal or petroleum-based waxes may be used. Carnauba palm is the most common plant-source wax. Other compounds, such as ethyl alcohol or ethanol, are added to the waxes for consistency, milk casein (a protein linked to milk allergy) for "film formers" and soaps for flowing agents. Since you may not be able to determine the source of these waxes, this is another good reason to choose organically grown lemons and limes.

Nutritional Profile
Lemons and limes are excellent sources of vitamin C and a good source of folate.

Healthy Food - Oranges

Healthy Food - Oranges. Juicy and sweet and renowned for its concentration of vitamin C, oranges make the perfect snack and add a special tang to many recipes; it is no wonder that they are one of the most popular fruits in the world. Oranges are generally available from winter through summer with seasonal variations depending on the variety.

Oranges are round citrus fruits with finely-textured skins that are, of course, orange in color just like their pulpy flesh; the skin can vary in thickness from very thin to very thick. Oranges usually range from approximately two to three inches in diameter.

Description

Oranges are one of the most popular fruits around the world. While they are delightful as a snack or as a recipe ingredient, for many Americans, it is their juice that is most associated with good health, having a reputation for being an integral part of a healthy breakfast.

Oranges are round citrus fruits with finely-textured skins that are, of course, orange in color just like their pulpy flesh. They usually range from about two to three inches in diameter.

Oranges are classified into two general categories sweet and bitter with the former being the type most commonly consumed. Popular varieties of the sweet orange (Citrus sinensis) include Valencia, Navel and Jaffa oranges, as well as the blood orange, a hybrid species that is smaller in size, more aromatic in flavor and has red hues running throughout its flesh. Bitter oranges (Citrus aurantium) are oftentimes used to make jam or marmalade, and their zest serves as the flavoring for liqueurs such as Grand Marnier and Cointreau.

History

Oranges originated thousands of years ago in Asia, in the region from southern China to Indonesia from which they spread to India. Although Renaissance paintings display oranges on the table in paintings of The Last Supper, the assumption that they were grown in this region at this time seems to be erroneous since oranges were not cultivated in the Middle East until sometime around the 9th century. Sweet oranges were introduced into Europe around the 15th century by various groups including the Moors, and the Portuguese as well as the Italian traders and explorers who found them on their voyages to Asia and the Middle East.

Orange trees began to be grown in the Caribbean Islands in the late 15th century after Christopher Columbus brought the seeds there on his second voyage to the New World. Spanish explorers are responsible for bringing oranges to Florida in the 16th century, while Spanish missionaries brought them to California in the 18th century, beginning the cultivation of this citrus fruit in the two states widely known for their oranges.

Before the 20th century, oranges were very expensive and therefore they were not regularly consumed, but rather eaten on special holidays such as Christmas. After more efficient means of transportation were developed, and food processors invented methods for utilizing orange by-products such as citric acid and bioflavonoids, the price of oranges dropped, and they could be consumed on a wide scale, as they are today. Currently, the countries that are some of the largest commercial producers of oranges include the United States, Brazil, Mexico, Spain, China and Israel.

Botanical information and terminology
All citrus trees belong to the single genus Citrus and remain almost entirely interfertile. This means that there is only one superspecies that includes grapefruits, lemons, limes, oranges, and various other types and hybrids. As the interfertility of oranges and other citrus has produced numerous hybrids, bud unions, and cultivars, their taxonomy is fairly controversial, confusing or inconsistent. The fruit of any citrus tree is considered a hesperidium (a kind of modified berry) because it has numerous seeds, is fleshy and soft, derives from a single ovary and is covered by a rind originated by a rugged thickening of the ovary wall.

Different names have been given to the many varieties of the genus. Orange applies primarily to the sweet orange Citrus sinensis (L.) Osbeck. The orange tree is an evergreen, flowering tree, with an average height of 9 to 10 m (30 to 33 ft), although some very old specimens can reach 15 m (49 ft).  Its oval leaves, alternately arranged, are 4 to 10 cm (1.6 to 3.9 in) long and have crenulate margins. Although the sweet orange presents different sizes and shapes varying from spherical to oblong, it generally has ten segments (carpels) inside, and contains up to six seeds (or pips) and a porous white tissue – called pith or, more properly, mesocarp or albedo lines its rind. When unripe, the fruit is green. The grainy irregular rind of the ripe fruit can range from bright orange to yellow-orange, but frequently retains green patches or, under warm climate conditions, remains entirely green. Like all other citrus fruits, the sweet orange is non-climacteric. The Citrus sinensis is subdivided into four classes with distinct characteristics: common oranges, blood or pigmented oranges, navel oranges, and acidless oranges.

Other citrus species also known as oranges are:

• the bitter orange (Citrus aurantium), also known as Seville orange, sour orange – especially when used as rootstock for a sweet orange tree –, bigarade orange and marmalade orange;
• the bergamot orange (Citrus bergamia Risso). It is grown mainly in Italy for its peel, which is used to flavor Earl Grey tea;
• the trifoliate orange (Poncirus trifoliata), sometimes included in the genus (classified as Citrus trifoliata). It often serves as a rootstock for sweet orange trees, especially as a hybrid with other Citrus cultivars. The trifoliate orange is a thorny shrub or small tree grown mostly as an ornamental plant or to set up hedges. It bears a downy fruit similar to a small citrus, used to make marmalade. It is native to northern China and Korea, and is also known as "Chinese bitter orange" or "hardy orange" because it can withstand subfreezing temperatures; and
• the mandarin orange (Citrus reticulata). It has an enormous number of cultivars, most notably the satsuma (Citrus unshiu), the tangerine (Citrus tangerina) and the clementine (Citrus clementina). In some cultivars, the mandarin is very similar to the sweet orange, making it difficult to distinguish between the two. The mandarin, however, is generally smaller and oblate, easier to peel, and less acidic.

Orange trees generally are grafted. The bottom of the tree, including the roots and trunk, is called rootstock, while the fruit-bearing top has two different names: budwood (when referring to the process of grafting) and scion (when mentioning the variety of orange).


Varieties

Common oranges
Common oranges (also called "white", "round", or "blond" oranges) constitute about two-thirds of all the orange production. The majority of this crop is used mostly for juice extraction. Healthy Food - Oranges.

Valencia
The Valencia orange is a late-season fruit, and therefore a popular variety when navel oranges are out of season. This is why an anthropomorphic orange was chosen as the mascot for the 1982 FIFA World Cup, held in Spain. The mascot was named Naranjito ("little orange") and wore the colors of the Spanish national football team.

Hamlin
This cultivar was discovered by A. G. Hamlin near Glenwood, Florida, in 1879. The fruit is small, smooth, not highly colored, seedless, and juicy, with a pale yellow colored juice, especially in fruits that come from lemon rootstock. The tree is high-yielding and cold-tolerant and it produces good quality fruit, which is harvested from October to December. It thrives in humid subtropical climates. In cooler, more arid areas, the trees produce edible fruit, but too small for commercial use.

Trees from groves in hammocks or areas covered with pine forest are budded on sour orange trees, a method that gives a high solids content. On sand, they are grafted on rough lemon rootstock. The Hamlin orange is one of the most popular juice oranges in Florida and replaces the Parson Brown variety as the principal early-season juice orange. This cultivar is now[needs update] the leading early orange in Florida and, possibly, in the rest of the world.

Other varieties of common oranges

• Belladonna: grown in Italy
• Berna: grown mainly in Spain
• Biondo Comune ("ordinary blond"): widely grown in the Mediterranean basin, especially in North Africa, Egypt, Greece (where it is called "koines"), Italy (where it is also known as "Liscio"), and Spain; it also is called "Beledi" and "Nostrale"; in Italy, this variety ripens in December, earlier than the competing Tarocco variety
• Biondo Riccio: grown in Italy
• Cadanera: a seedless orange of excellent flavor grown in Algeria, Morocco, and Spain; it begins to ripen in November and is known by a wide variety of trade names, such as Cadena Fina, Cadena sin Jueso, Precoce de Valence ("early from Valencia"), Precoce des Canaries, and Valence san Pepins ("seedless Valencia"); it was first grown in Spain in 1870
• Calabrese or Calabrese Ovale: grown in Italy
• Carvalhal: grown in Portugal
• Castellana: grown in Spain
• Cherry Orange: grown in southern China and Japan
• Clanor: grown in South Africa
• Dom João: grown in Portugal
• Fukuhara: grown in Japan
• Gardner: grown in Florida, this mid-season orange ripens around the beginning of February, approximately the same time as the Midsweet variety; Gardner is about as hardy as Sunstar and Midsweet
• Homosassa: grown in Florida
• Jaffa orange: grown in the Middle East, also known as "Shamouti"
• Jincheng: the most popular orange in China
• Joppa: grown in South Africa and Texas
• Khettmali: grown in Israel and Lebanon
• Kona: a type of Valencia orange introduced in Hawaii in 1792 by Captain George Vancouver; for many decades in the nineteenth century, these oranges were the leading export from the Kona district on the Big Island of Hawaii; in Kailua-Kona, some of the original stock still bears fruit
• Lue Gim Gong: grown in Florida, is an early scion developed by Lue Gim Gong, a Chinese immigrant known as the "Citrus Genius"; in 1888, Lue cross-pollinated two orange varieties – the Hart's late Valencia and the Mediterranean Sweet – and obtained a fruit both sweet and frost-tolerant; this variety was propagated at the Glen St. Mary Nursery, which in 1911 received the Silver Wilder Medal by the American Pomological Society; originally considered a hybrid, the Lue Gim Gong orange was later found to be a nucellar seedling of the Valencia type, which is properly called Lue Gim Gong; since 2006, the Lue Gim Gong variety is grown in Florida, although sold under the general name Valencia
• Macetera: grown in Spain, it is known for its unique flavor
• Malta: grown in Pakistan
• Maltaise Blonde: grown in north Africa
• Maltaise Ovale: grown in South Africa and in California under the names of Garey's or California Mediterranean Sweet
• Marrs: grown in Texas, California and Iran, it is relatively low in acid
• Midsweet: grown in Florida, it is a newer scion similar to the Hamlin and Pineapple varieties, it is hardier than Pineapple and ripens later; the fruit production and quality are similar to those of the Hamlin, but the juice has a deeper color
• Moro Tarocco: grown in Italy, it is oval, resembles a tangelo, and has a distinctive caramel-colored endocarp; this color is the result of a pigment called anthocarpium, not usually found in citruses, but common in red fruits and flowers; the original mutation occurred in Sicily in the seventeenth century
• Mosambi: grown in India and Pakistan, it is so low in acid and insipid that it might be classified as acidless
• Narinja: grown in Andhra, South India
• Parson Brown: grown in Florida, Mexico, and Turkey, it once was a widely-grown Florida juice orange, its popularity has declined since new varieties with more juice, better yield, and higher acid and sugar content have been developed; it originated as a chance seedling in Florida in 1865; its fruits are round, medium large, have a thick, pebbly peel and contain 10 to 30 seeds; it still is grown because it is the earliest maturing fruit in the United States, usually maturing in early September in the Valley district of Texas, and from early October to January in Florida; its peel and juice color are poor, as is the quality of its juice
• Pera: grown in Brazil, it is very popular in the Brazilian citrus industry and yielded 7.5 million metric tons in 2005
• Pera Coroa: grown in Brazil
• Pera Natal: grown in Brazil
• Pera Rio: grown in Brazil
• Pineapple: grown in North and South America and India
• Premier: grown in South Africa
• Rhode Red: is a mutation of the Valencia orange, but the color of its flesh is more intense; it has more juice, and less acidity and vitamin C than the Valencia; it was discovered by Paul Rhode in 1955 in a grove near Sebring, Florida
• Roble: it was first shipped from Spain in 1851 by Joseph Roble to his homestead in what now is Roble's Park in Tampa, Florida; it is known for its high sugar content
• Queen: grown in South Africa
• Salustiana: grown in North Africa
• Sathgudi: grown in Tamil Nadu, South India
• Seleta, Selecta: grown in Australia and Brazil, it is high in acid
• Shamouti Masry: grown in Egypt; it is a richer variety of Shamouti
• Sunstar: grown in Florida, this newer cultivar ripens in mid-season (December to March) and it is more resistant to cold and fruit-drop than the competing Pineapple variety; the color of its juice is darker than that of the competing Hamlin
• Tomango: grown in South Africa
• Verna: grown in Algeria, Mexico, Morocco, and Spain
• Vicieda: grown in Algeria, Morocco, and Spain
• Westin: grown in Brazil

Navel oranges

Navel oranges are characterized by the growth of a second fruit at the apex, which protrudes slightly and resembles a human navel. They are primarily grown for human consumption for various reasons: their thicker skin makes them easy to peel, they are less juicy and their bitterness a result of the high concentrations of limonin and other limonoids renders them less suitable for juice. Their widespread distribution and long growing season have made navel oranges very popular. In the United States, they are available from November to April, with peak supplies in January, February, and March.

According to a 1917 study by Palemon Dorsett, Archibald Dixon Shamel and Wilson Popenoe of the United States Department of Agriculture (USDA), a single mutation in a Selecta orange tree planted on the grounds of a monastery near Bahia, Brazil, probably yielded the first navel orange between 1810 and 1820. Nevertheless, a researcher at the University of California, Riverside, has suggested that the parent variety was more likely the Portuguese navel orange (Umbigo), described by Antoine Risso and Pierre Antoine Poiteau in their book Histoire naturelle des orangers ("Natural History of Orange Trees", 1818–1822). The mutation caused the orange to develop a second fruit at its base, opposite the stem, as a conjoined twin in a set of smaller segments embedded within the peel of the primary orange. Navel oranges were introduced in Australia in 1824 and in Florida in 1835. In 1870, twelve cuttings of the original tree were transplanted to Riverside, California, where the fruit became known as "Washington". This cultivar was very successful, and rapidly spread to other countries. Because the mutation left the fruit seedless and, therefore, sterile, the only method to cultivate navel oranges was to graft cuttings onto other varieties of citrus trees. The California Citrus State Historic Park and the Orcutt Ranch Horticulture Center preserve the history of navel oranges in Riverside.

Today, navel oranges continue to be propagated through cutting and grafting. This does not allow for the usual selective breeding methodologies, and so all navel oranges can be considered fruits from that single, nearly two-hundred-year-old tree: they have exactly the same genetic make-up as the original tree and are, therefore, clones. This case is similar to that of the common yellow seedless banana, the Cavendish. On rare occasions, however, further mutations can lead to new varieties.

Cara cara navels
Cara cara oranges (also called "red navel") are a type of navel orange grown mainly in Venezuela, South Africa and in California's San Joaquin Valley. They are sweet and comparatively low in acid, with a bright orange rind similar to that of other navels, but their flesh is distinctively pinkish red. It is believed that they have originated as a cross between the Washington navel and the Brazilian Bahia navel, and they were discovered at the Hacienda Cara Cara in Valencia, Venezuela, in 1976.

South African cara caras are ready for market in early August, while Venezuelan fruits arrive in October and Californian fruits in late November. Healthy Food - Oranges.

Other varieties of navels

• Bahianinha or Bahia
• Dream Navel
• Late Navel
• Washington or California Navel

Blood oranges

Blood oranges are a natural mutation of C. sinensis, although today the majority of them are hybrids. High concentrations of anthocyanin give the rind, flesh, and juice of the fruit their characteristic dark red color. Blood oranges were first discovered and cultivated in Sicily in the fifteenth century. Since then they have spread worldwide, but are grown especially in Spain and Italy—under the names of sanguina and sanguinella, respectively.

The blood orange, with its distinct color and flavor, is generally considered the most delicious juice orange, and has found a niche as an ingredient variation in traditional Seville marmalade.

Other varieties of blood oranges

• Maltese: a small and highly colored variety, generally thought to have originated in Italy as a mutation and cultivated there for centuries. It also is grown extensively in southern Spain and Malta. It is used in sorbets and other desserts due to its rich burgundy color.
• Moro: originally from Sicily, it is common throughout Italy. This medium-sized fruit has a relatively long harvest, which lasts from December to April.
• Sanguinelli: a mutant of the Doble Fina, discovered in 1929 in Almenara, in the Castellón province of Spain. It is cultivated in Sicily.
• Scarlet navel: a variety with the same mutation as the navel orange.
• Tarocco: a relatively new variety developed in Italy. It begins to ripen in late January.

Acidless oranges
Acidless oranges are an early-season fruit with very low levels of acid. They also are called "sweet" oranges in the US, with similar names in other countries: douce in France, sucrena in Spain, dolce or maltese in Italy, meski in North Africa and the Near East (where they are especially popular), şeker portakal ("sugar orange") in Turkey, succari in Egypt, and lima in Brazil.


The lack of acid, which protects orange juice against spoilage in other groups, renders them generally unfit for processing as juice, so they are primarily eaten. They remain profitable in areas of local consumption, but rapid spoilage renders them unsuitable for export to major population centres of Europe, Asia, or the United States.

Health Benefits

A Glass of Orange Juice More Protective than Vitamin C Alone
Consuming vitamin C supplements does not provide the same protective benefits as drinking a glass of orange juice, shows research by Italian researchers in the Division of Human Nutrition at the University of Milan, Italy (Guarnieri S, Riso P, et al., British Journal of Nutrition).

Seven healthy test subjects were given each of three drinks, two weeks apart: blood-orange juice containing 150 milligrams of vitamin C, fortified water containing 150 milligrams of vitamin C, and a sugar and water solution containing no vitamin C. Blood samples were collected immediately before the drink was consumed, then every hour for 8 hours, and finally 24 hours after consumption of each drink.

Blood samples were exposed to hydrogen peroxide, and free radical damage to DNA was evaluated at 3 and 24 hours. Only when orange juice was consumed was any protective effect seen. After drinking orange juice, DNA damage was 18% less after 3 hours, and 16% less after 24 hours. No protection against DNA damage was seen after consumption of the vitamin C fortified drink or the sugar drink.

While another study, which looked at much larger quantities of vitamin C, did show a protective effect from the vitamin alone, this research indicates that not only is the protection afforded by fruit more complex, but smaller amounts of nutrients like vitamin C are all that are needed for benefit.

Said lead researcher, Serena Guarnieri, "It appears that vitamin C is not the only chemical responsible for antioxidant protection." In oranges, vitamin C is part of a matrix involving many beneficial phytochemicals (for example, cyanidin-3-glucoside, flavanones and carotenoids)."But how they are interacting is still anyone's guess," she added. Fortunately, we don't have to wait until scientists figure this out to receive oranges' DNA-protective benefits. Practical Tip: For the best DNA protection, skip the vitamin C—fortified bottled drinks and enjoy a glass of real (preferably organic as organic foods have been shown to contain higher amounts of phytonutrients), freshly squeezed orange juice—or simply eat an orange!

Owing to the multitude of vitamin C's health benefits, it is not surprising that research has shown that consumption of vegetables and fruits high in this nutrient is associated with a reduced risk of death from all causes including heart disease, stroke and cancer.

A Healthy Dose of Vitamin C for Antioxidant Protection and Immune Support
You may already know that oranges are an excellent source of vitamin C but do you know just how important vitamin C and oranges are for good health? Vitamin C is the primary water-soluble antioxidant in the body, disarming free radicals and preventing damage in the aqueous environment both inside and outside cells. Inside cells, a potential result of free radical damage to DNA is cancer. Especially in areas of the body where cellular turnover is especially rapid, such as the digestive system, preventing DNA mutations translates into preventing cancer. This is why a good intake of vitamin C is associated with a reduced risk of colon cancer.

Free radical damage to other cellular structures and other molecules can result in painful inflammation, as the body tries to clear out the damaged parts. Vitamin C, which prevents the free radical damage that triggers the inflammatory cascade, is thus also associated with reduced severity of inflammatory conditions, such as asthma, osteoarthritis, and rheumatoid arthritis.

Free radicals also oxidize cholesterol. Only after being oxidized does cholesterol stick to the artery walls, building up in plaques that may eventually grow large enough to impede or fully block blood flow, or rupture to cause a heart attack or stroke. Since vitamin C can neutralize free radicals, it can help prevent the oxidation of cholesterol.

Vitamin C, which is also vital for the proper function of a healthy immune system, is good for preventing colds and may be helpful in preventing recurrent ear infections.

A Very Good Source of Fiber
Oranges' health benefits continue with their fiber, which has been shown to reduce high cholesterol levels thus helping to prevent atherosclerosis. Fiber can also help out by keeping blood sugar levels under control, which may help explain why oranges can be a very healthy snack for people with diabetes. In addition, the natural fruit sugar in oranges, fructose, can help to keep blood sugar levels from rising too high after eating. The fiber in oranges can grab cancer-causing chemicals and keep them away from cells of the colon, providing yet another line of protection from colon cancer. And the fiber in oranges may be helpful for reducing the uncomfortable constipation or diarrhea in those suffering from irritable bowel syndrome.

In addition to oranges' phytonutrients, vitamin C, and fiber, they are a good source of folate, vitamin A (in the form of carotenoids), vitamin B1, potassium, copper, pantothenic acid, and calcium.

Long-Acting Liminoids in Citrus Add to Their Ability to Promote Optimal Health
In animal studies and laboratory tests with human cells, compounds in citrus fruits, including oranges, called limonoids have been shown to help fight cancers of the mouth, skin, lung, breast, stomach and colon. Now, scientists from the US Agricultural Research Service have shown that our bodies can readily absorb and utilize a very long-acting limonoid called limonin that is present is citrus fruits in about the same amount as vitamin C.

In citrus fruits, limonin is present in the form of limonin glucoside, in which limonin is attached to a sugar (glucose) molecule. Our bodies easily digest this compound, cleaving off the sugar and releasing limonin.

In the ARS study, 16 volunteers were given a dose of limonin glucoside in amounts ranging from those that would be found in from 1 to 7 glasses of orange juice. Blood tests showed that limonin was present in the plasma of all except one of the subjects, with concentrations highest within 6 hours after consumption. Traces of limonin were still present in 5 of the volunteers 24 hours after consumption!

Limonin's bioavailability and persistence may help explain why citrus limonoids are potent anti-carcinogens that may continuously prevent cancerous cells from proliferating. Other natural anti-carcinogens are available for much less time; for example, the phenols in green tea and chocolate remain active in the body for just 4 to 6 hours.

Oranges' Healing Phytonutrients
In recent research studies, the healing properties of oranges have been associated with a wide variety of phytonutrient compounds. These phytonutrients include citrus flavanones (types of flavonoids that include the molecules hesperetin and naringenin), anthocyanins, hydroxycinnamic acids, and a variety of polyphenols. When these phytonutrients are studied in combination with oranges—vitamin C, the significant antioxidant properties of this fruit are understandable.

But it is yet another flavanone in oranges, the herperidin molecule, which has been singled out in phytonutrient research on oranges. Arguably, the most important flavanone in oranges, herperidin has been shown to lower high blood pressure as well as cholesterol in animal studies, and to have strong anti-inflammatory properties. Importantly, most of this phytonutrient is found in the peel and inner white pulp of the orange, rather than in its liquid orange center, so this beneficial compound is too often removed by the processing of oranges into juice.

Possible Cholesterol-Lowering Benefits
The ARS team is now investigating the potential cholesterol-lowering effects of limonin. Lab tests indicate that human liver cells produce less apo B when exposed to limonin. Apo B is a structural protein that is part of the LDL cholesterol molecule and is needed for LDL production, transport and binding, so higher levels of apo B translate to higher levels of LDL cholesterol.
Compounds in Orange Peel May Lower Cholesterol as Effectively as Statin Drugs

A class of compounds found in citrus fruit peels called polymethoxylated flavones (PMFs) have the potential to lower cholesterol more effectively than some prescription drugs, and without side effects, according to a study by U.S. and Canadian researchers that was published in the Journal of Agricultural and Food Chemistry.

In this study, when laboratory animals with diet-induced high cholesterol were given the same diet containing 1% PMFs (mainly tangeretin), their blood levels of total cholesterol, VLDL and LDL (bad cholesterol) were reduced by 19-27 and 32-40% respectively. Comparable reductions were also seen when the animals were given diets containing a 3% mixture of two other citrus flavonones, hesperidin and naringin.

Treatment with PMFs did not appear to have any effect on levels of beneficial HDL cholesterol, and no negative side effects were seen in the animals fed the PMF-containing diets.

Although a variety of citrus fruits contain PMFs, the most common PMFs, tangeretin and nobiletin, are found in the peels of tangerines and oranges. Juices of these fruits also contain PMFs, but in much smaller amounts. In fact, you'd have to drink about 20 glasses of juice each day to receive an amount of PMFs comparable in humans to that given to the animals. However, grating a tablespoon or so of the peel from a well-scrubbed organic tangerine or orange each day and using it to flavor tea, salads, salad dressings, yogurt, soups, or hot oatmeal, buckwheat or rice may be a practical way of achieving some cholesterol-lowering benefits. The researchers are currently exploring the mechanism of action by which PMFs lower cholesterol. Based on early results in cell and animal studies, they suspect that PMFs work like statin drugs, by inhibiting the synthesis of cholesterol and triglycerides inside the liver.

Prevent Kidney Stones
Want to reduce your risk of calcium oxalate kidney stones? Drink orange juice. A study published in the British Journal of Nutrition found that when women drank 1/2 to 1 litre of orange, grapefruit or apple juice daily, their urinary pH value and citric acid excretion increased, significantly dropping their risk of forming calcium oxalate stones.
Help Prevent Ulcers and Reduce Risk for Stomach Cancer

An orange a day may help keep ulcers away, according to a study published in the Journal of the American College of Nutrition. In this study, researchers evaluated data from over 6,000 adults enrolled in the Third National Health and Nutrition Examination Survey. Study participants with the highest blood levels of vitamin C had a 25% lower incidence of infection with Helicobacter pylori (H. pylori), the bacterium responsible for causing peptic ulcers and in turn, an increased risk for stomach cancer. Researchers are uncertain whether H. pylori lowers blood levels of vitamin C or if high blood levels of vitamin C help protect against infection—either way, eating an orange or drinking a glass of orange juice each day may help prevent gastric ulcers. Lead researcher in this study, Dr. Joel A. Simon at the San Francisco VA Medical Center, urges people who have tested positive for H. pylori to increase their consumption of vitamin C-rich foods since this may help them combat H. pylori infection.

Protect Respiratory Health
Consuming foods rich in beta-cryptoxanthin, an orange-red carotenoid found in highest amounts in oranges, corn, pumpkin, papaya, red bell peppers, tangerines, and peaches, may significantly lower one's risk of developing lung cancer. A study published in the September 2003 issue of Cancer Epidemiology, Biomarkers and Prevention reviewed dietary and lifestyle data collected from over 60,000 adults in Shanghai, China. Those eating the most crytpoxanthin-rich foods showed a 27% reduction in lung cancer risk. When current smokers were evaluated, those who were also in the group consuming the most cryptoxanthin-rich foods were found to have a 37% lower risk of lung cancer compared to smokers who ate the least of these health-protective foods.
Protection Against Rheumatoid Arthritis

New research published in the American Journal of Clinical Nutrition adds to the evidence that enjoying a daily glass of freshly squeezed orange juice can significantly lower your risk of developing rheumatoid arthritis.

Data collected by the European Prospective Investigation of Cancer Incidence (EPIC)-Norfolk study, a population-based, prospective study of over 25,000 subjects, showed that study participants with the highest daily intake of the carotenoids, zeaxanthin and beta-cryptoxanthin, had a much lower risk of developing rheumatoid arthritis compared to individuals consuming the least of these beneficial phytonutrients. Those whose intake of zeaxanthin was highest were 52% less likely to develop rheumatoid arthritis, while those with the highest intake of cryptoxanthin had a 49% reduction in risk. Pretty dramatic benefits for doing something as simple as enjoying a glass of freshly squeezed orange juice each day!

Protection against Cardiovascular Disease
A 248-page report, "The Health Benefits of Citrus Fruits," released December 2003 by Australian research group, CSIRO (The Commonwealth Scientific and Industrial Research), reviews 48 studies that show a diet high in citrus fruit provides a statistically significant protective effect against some types of cancer, plus another 21 studies showing a non-significant trend towards protection.

Citrus appears to offer the most significant protection against esophageal, oro-phayngeal/laryngeal (mouth, larynx and pharynx), and stomach cancers. For these cancers, studies showed risk reductions of 40-50%.

The World Health Organization's recent draft report, "Diet, Nutrition and the Prevention of Chronic Disease," concludes that a diet that features citrus fruits also offers protection against cardiovascular disease due to citrus fruits—folate, which is necessary for lowering levels of the cardiovascular risk factor, homocysteine; their, potassium, which helps lower blood pressure, protecting against stroke and cardiac arrhythmias; and the vitamin C, carotenoids and flavonoids found in citrus fruits, all of which have been identified as having protective cardiovascular effects.

One large US study reviewed in the CSIRO report showed that one extra serving of fruit and vegetables a day reduced the risk of stroke by 4%, and this increased by 5-6 times for citrus fruits, reaching a 19% reduction of risk for stroke from consuming one extra serving of citrus fruit a day.

The CSIRO Report also includes evidence of positive effects associated with citrus consumption in studies for arthritis, asthma, Alzheimer's disease and cognitive impairment, Parkinson's disease, macular degeneration, diabetes, gallstones, multiple sclerosis, cholera, gingivitis, optimal lung function, cataracts, ulcerative colitis and Crohn's disease.

Finally, the CSIRO Report notes that as low fat, nutrient-rich foods with a low glycemic index, citrus fruits are protective against overweight and obesity, conditions which increase the risk of heart disease, certain cancers, diabetes, high blood pressure and stroke, and add to symptoms of other conditions like arthritis.

An orange has over 170 different phytonutrients and more than 60 flavonoids, many of which have been shown to have anti-inflammatory, anti-tumour and blood clot inhibiting properties, as well as strong antioxidant effects.

Phytonutrients, specifically, the class of polyphenols, are high in citrus with oranges containing 84mg Gallic Acid equivalents/100mg. The polyphenols so abundant in oranges have been shown to have a wide range of antioxidant, anti-viral, anti-allergenic, anti-inflammatory, anti-proliferative and anti-carcinogenic effects. Although most of the research has centered on citrus polyphenols—possible role in cancer and heart disease, more recently, scientists have begun to look at their role in brain functions such as learning and memory.

An increasing number of studies have also shown a greater absorption of the nutrients in citrus when taken not as singly as supplements, but when consumed within the fruit in which they naturally appear along with all the other biologically active phytonutrients that citrus fruits contain. Healthy Food - Oranges.

How to Select and Store
Oranges do not necessarily have to have a bright orange color to be good. In fact, the uniform color of non-organic oranges may be due to injection of Citrus Red Number 2 (an artificial dye) into their skins at the level of 2 parts per million. Whether organic or not, oranges that are partially green or have brown russetting may be just as ripe and tasty as those that are solid orange in color. Avoid those that have soft spots or traces of mold. And, because oranges are among the top 20 foods in which pesticide residues are most frequently found, buy organic oranges whenever possible.

Choose oranges that have smoothly textured skin and are firm and heavy for their size. These will have a higher juice content than those that are either spongy or lighter in weight. In general, oranges that are smaller will be juicier than those that are larger in size, as will those that feature thinner skins.

Oranges can either be stored at room temperature or in the refrigerator, depending upon your preference. They will generally last the same amount of time, two weeks with either method, and will retain nearly the same level of their vitamin content. The best way to store oranges is loose rather than wrapped in a plastic bag since if exposed to moisture, they can easily develop mold.

Orange juice and zest can also be stored for later use. Place freshly squeezed orange juice in ice cube trays until frozen, and then store them in plastic bags in the freezer. Dried orange zest should be stored in a cool, dry place in an airtight glass container.

Grading
The United States Department of Agriculture (USDA) has established the following grades for Florida oranges, which primarily apply to oranges sold as fresh fruit: US Fancy, US No. 1 Bright, US No. 1, US No. 1 Golden, US No. 1 Bronze, US No. 1 Russet, US No. 2 Bright, US No. 2, US No. 2 Russet, and US No. 3. The general characteristics graded are color (both hue and uniformity), firmness, maturity, varietal characteristics, texture, and shape. Fancy, the highest grade, requires the highest grade of color and an absence of blemishes, while the terms Bright, Golden, Bronze, and Russet concern solely discoloration.

Grade numbers are determined by the amount of unsightly blemishes on the skin and firmness of the fruit that do not affect consumer safety. The USDA separates blemishes into three categories:

• General blemishes: ammoniation, buckskin, caked melanose, creasing, decay, scab, split navels, sprayburn, undeveloped segments, unhealed segments, and wormy fruit
• Injuries to fruit: bruises, green spots, oil spots, rough, wide, or protruding navels, scale, scars, skin breakdown, and thorn scratches
• Damage caused by dirt or other foreign material, disease, dryness, or mushy condition, hail, insects, riciness or woodiness, and sunburn.

The USDA uses a separate grading system for oranges used for juice because appearance and texture are irrelevant in this case. There are only two grades: US Grade AA Juice and US Grade A Juice, which are given to the oranges before processing. Juice grades are determined by three factors:

• The juiciness of the orange
• The amount of solids in the juice (at least 10% solids are required for the AA grade)
• The proportion of anhydric citric acid in fruit solids

Tips for Preparing and Cooking

Tips for Preparing Oranges
Oranges can be eaten as a snack just peel and enjoy. Before cutting the orange in half horizontally through the center, wash the skin so that any dirt or bacteria residing on the surface will not be transferred to the fruit. Proceed to cut the sections into halves or thirds, depending upon your personal preference.

Thin-skinned oranges can be easily peeled with your fingers. For easy peeling of the thicker skinned varieties, first cut a small section of the peel from the top of the orange. You can then either make four longitudinal cuts from top to bottom and peel away these sections of skin, or starting at the top, peel the orange in a spiral fashion.

Oranges are oftentimes called for in recipes in the form of orange juice. As oranges, like most citrus fruits, will produce more juice when warmer, always juice them when they are at room temperature. Rolling the orange under the palm of your hand on a flat surface will also help to extract more juice.

The juice can be extracted in a variety of ways. You could either use a juicer or do it the old fashioned way, squeezing by hand.

If your recipe calls for orange zest, make sure that you use an orange that is organically grown since most conventionally grown fruits will have pesticide residues on their skin and may be artificially colored. After washing and drying the orange, use a zester, paring knife or vegetable peeler to remove the zest, which is the orange part of the peel. Make sure not to remove too much of the peel as the white pith underneath is bitter and should not be used. The zest can then be more finely chopped or diced if necessary.

How to Enjoy

A Few Quick Serving Ideas

• Gently simmer sweet potatoes, winter squash and orange segments in orange juice. Before serving, sprinkle with walnuts.
• Healthy sauté onions and ginger, and then deglaze the pan with orange juice. Use this liquid as a sauce for salmon or tuna.
• Orange segments, fennel and boiled beets make a delightfully refreshing salad.

Juice and other products

Oranges, whose flavor may vary from sweet to sour, are commonly peeled and eaten fresh or squeezed for juice. The thick bitter rind is usually discarded, but can be processed into animal feed by desiccation, using pressure and heat. It also is used in certain recipes as a food flavoring or garnish. The outermost layer of the rind can be thinly grated with a zester to produce orange zest. Zest is popular in cooking because it contains the oil glands and has a strong flavor similar to that of the orange pulp. The white part of the rind, including the pith, is a source of pectin and has nearly the same amount of vitamin C as the flesh and other nutrients.

Although not so juicy or tasty as the flesh, orange peel is edible and has higher contents of vitamin C and more fibre. It also contains citral, an aldehyde that antagonizes the action of vitamin A. Particularly in environments where resources are scarce and therefore maximum nutritional value must be obtained with the minimum generation of waste, for example, on a submarine, orange peels have been consumed routinely. Since large concentrations of pesticides have been found in orange peels, some organizations[which?] recommend consumption of the peel of only organically grown and processed oranges, where chemical pesticides or herbicides have not been used.

Products made from oranges

• Orange juice is obtained by squeezing the fruit on a special tool (a juicer or squeezer) and collecting the juice in a tray underneath. This can be made at home or, on a much larger scale, industrially. Brazil is the largest producer of orange juice in the world, followed by the US, where it is one of the commodities traded on the New York Board of Trade.
• Frozen orange juice concentrate is made from freshly squeezed and filtered orange juice.
• Sweet orange oil is a by-product of the juice industry produced by pressing the peel. It is used for flavoring food and drinks and also in the perfume industry and aromatherapy for its fragrance. Sweet orange oil consists of approximately 90% D-limonene, a solvent used in various household chemicals, such as wood conditioners for furniture and along with other citrus oils detergents and hand cleansers. It is an efficient cleaning agent with a pleasant smell, promoted for being environmentally friendly and therefore, preferable to petrochemicals. D-limonene is, however, classified from slightly toxic to humans, to very toxic to marine life in different countries.

Although once thought to cause renal cancer in rats, limonene is now considered a natural chemopreventive agent in humans, since there is no evidence for its carcinogenicity or genotoxicity. The Carcinogenic Potency Project estimates that D-limonene causes human cancer on a level roughly equivalent to that caused by exposure to caffeic acid via dietary coffee intake, whereas the International Agency for Research on Cancer (IARC) classifies it under Class 3, which means it is not classifiable as to its carcinogenicity to humans.

Orange blossoms are used in several different ways, as are fruit peels and the leaves and wood of the tree.

• The orange blossom, which is the state flower of Florida, is highly fragrant and traditionally associated with good fortune. It has long been popular in bridal bouquets and head wreaths.
• Orange blossom essence is an important component in the making of perfume.
• Orange blossom petals can also be made into a delicately citrus-scented version of rosewater, known as "orange blossom water" or "orange flower water". It is a common ingredient in French and Middle Eastern cuisines, especially in desserts and baked goods. In some Middle Eastern countries, drops of orange flower water are added to disguise the unpleasant taste of hard water drawn from wells or stored in qullahs (traditional Egyptian water pitchers made of porous clay). In the United States, orange flower water is used to make orange blossom scones and marshmallows.
• In Spain, fallen blossoms are dried and used to make tea.
• Orange blossom honey (or citrus honey) is obtained by putting beehives in the citrus groves while trees bloom. By this method, bees also pollinate seeded citrus varieties. This type of honey has an orangey taste and is highly prized.
• Marmalade usually is made with Seville oranges. All parts of the fruit are used: the pith and pips (separated and placed in a muslin bag) are boiled in a mixture of juice, slivered peel, sliced-up flesh, sugar, and water to extract their pectin, which helps the conserve to set.
• Orange peel is used by gardeners as a slug repellent.
• Orange leaves can be boiled to make tea.
• Orangewood sticks are used as cuticle pushers in manicures and pedicures, and as spudgers for manipulating slender electronic wires.
• Orangewood is used in the same way as mesquite, oak, and hickory for seasoning grilled meat.

Nutritional Profile
Oranges are an excellent source of vitamin C. They are also a very good source of dietary fiber. In addition, oranges are a good source of B vitamins including vitamin B1, pantothenic acid, and folate as well as vitamin A, calcium, copper, and potassium. Healthy Food - Oranges.