Botanical vs. culinaryMany common language terms used for fruit and seeds differ from botanical classifications. For example, in botany, a ''fruit'' is a ripened or that contains seeds; e.g., an apple, pomegranate, tomato or a pumpkin. A '' '' is a type of fruit (and not a seed), and a ''seed'' is a ripened . In culinary language, a ''fruit'', so-called, is the sweet- or not sweet- (even sour-) tasting produce of a specific plant (e.g., a peach, pear or lemon); ''nuts'' are hard, oily, non-sweet plant produce in shells ( , ). '' '', so called, typically are or non-sweet produce ( , lettuce, broccoli, and tomato); but some may be sweet-tasting (sweet potato). Examples of botanically classified fruit that typically are called vegetables include: , , and ( all are cucurbits); s, s, and s ( ); , , bell pepper (or sweet pepper), and tomato, (see image). The spices and are fruits, botanically speaking. In contrast, is often called a fruit when used in making , but the edible produce of rhubarb is actually the leaf stalk or of the plant. Edible seeds are often given fruit names, e.g., nuts and s. Botanically, a grain, such as , , or is a kind of fruit (termed a ). However, the fruit wall is thin and fused to the seed coat, so almost all the edible grain-fruit is actually a seed.
StructureThe outer layer, often edible, of most fruits is called the ''pericarp''. Typically formed from the ovary, it surrounds the seeds; in some species, however, other structural tissues contribute to or form the edible portion. The pericarp may be described in three layers from outer to inner, i.e., the ''epicarp'', ''mesocarp'' and ''endocarp''. Fruit that bears a prominent pointed terminal projection is said to be ''beaked''.
DevelopmentA fruit results from the fertilizing and maturing of one or more flowers. The , which contains the '' stigma-style-ovary'' system, is centered in the flower-head, and it forms all or part of the fruit —(see graphic: 'the parts of a flower'). Inside the ovary(ies) are one or more s. Here begins a complex sequence called '' '': a female produces an egg cell for the purpose of fertilization. (A female gametophyte is called a , and also called the .) After , the ovules will become seeds. Ovules are fertilized in a process that starts with , which is the movement of pollen from the stamens to the stigma-style-ovary system within the flower-head, (see graphic). After pollination, a grows from the (deposited) pollen through the stigma down the style into the ovary to the ovule. Two sperm are transferred from the pollen to a megagametophyte. Within the megagametophyte one sperm unites with the egg, forming a , while the second sperm enters the central cell forming the endosperm mother cell, which completes the double fertilization process. Later the zygote will give rise to the embryo of the seed, and the endosperm mother cell will give rise to , a nutritive tissue used by the embryo. image:Ovary position.svg, upright 1.5, Insertion point: There are 3 positions of insertion of the ovary at the base of a flower: I superior; II half-inferior; III inferior. The 'insertion point' is where the androecium parts ''(a)'', the petals ''(p)'', and the sepals ''(s)'' all converge and attach to the receptacle ''(r)''. (Ovary= gynoecium ''(g)''.) As the ovules develop into seeds, the ovary begins to ripen and the ovary wall, the ''pericarp'', may become fleshy (as in berries or s), or it may form a hard outer covering (as in nuts). In some multiseeded fruits, the extent to which a fleshy structure develops is proportional to the number of fertilized ovules. The pericarp typically is differentiated into two or three distinct layers; these are called the ''exocarp'' (outer layer, also called epicarp), ''mesocarp'' (middle layer), and ''endocarp'' (inner layer) —(see image of apple-section). In some fruits the s, s, s and/or of the flower fall away as the fleshy fruit ripens. However, for simple fruits derived from an '' '' —i.e., one that lies ''below'' the attachment of other floral parts, (see graphic re 'insertion point')— there are parts (including petals, sepals, and stamens) that fuse with the ovary and ripen with it. For such a case, when floral parts other than the ovary form a significant part of the fruit that develops, it is called an . Examples of accessory fruits include apple, rose hip, strawberry, pineapple; , and "Table of fleshy fruit examples". Because several parts of the flower besides the ovary may contribute to the structure of a fruit, it is important to study flower structure to understand how a particular fruit forms. There are three general modes of fruit development: * fruits develop from a ''single flower'' (while having one or more separate, unfused, carpels); they are the simple fruits. * fruits develop from a ''single '' (having two or more carpels fused together). * Multiple fruits form from many flowers —i.e., an inflorescence of flowers.
Classification of fruitsConsistent with the three modes of fruit development plant scientists have classified fruits into three main groups: simple fruits, aggregate fruits, and multiple (or composite) fruits. The groupings reflect how the ovary and other flower organs are arranged and how the fruits develop, but they are not evolutionarily relevant as diverse plant may be in the same group. While the section of a that produces s is called a ''fruiting'' body, fungi are members of the and not of the .
Simple fruitsupright 1.02, A dry simple fruit: milkweed ('' '');_dehiscence_of_the_Follicle_(fruit)">follicular_fruit_reveals_seeds_within..html" ;"title="Follicle_(fruit).html" ;"title="Asclepias syriaca''); dehiscence of the ;_and_the_merging_of_several_flowers,_or_a_'multiple'_of_flowers,_results_in_a_'multiple'_fruit.
BerriesBerries are a type of simple fleshy fruit that issue from a single ovary. (The ovary itself may be compound, with several carpels.) The botanical term "true berry" includes grapes, currants, cucumbers, eggplants (aubergines), tomatoes, chili peppers, and bananas, but excludes certain fruits that are called "-berry" by culinary custom or by common usage of the term —such as strawberries and raspberries. Berries may be formed from one or more carpels (i.e., from the simple or compound ovary) from the same, single flower. Seeds typically are embedded in the fleshy interior of the ovary. Examples here and in the table below: * – In culinary terms, the tomato is regarded as a vegetable, but it is botanically classified as a fruit and a berry. * – The fruit has been described as a "leathery berry". In cultivated varieties, the seeds are diminished nearly to non-existence. * Pepo (botany), pepo – Berries with skin that is hardened: Cucurbitaceae, cucurbits, including gourds, squash, melons. * hesperidium – Berries with a rind and a juicy interior: most citrus fruit. * cranberry, gooseberry, redcurrant, . The ''strawberry'', regardless of its appearance, is classified as a dry, not a fleshy fruit. Botanically, it is ''not'' a berry (botany)#Accessory fruits, berry; it is an accessory fruit, aggregate-accessory fruit, the latter term meaning the fleshy part is derived not from the plant's ovaries but from the Receptacle (botany), receptacle that holds the Ovary (botany), ovaries.Esau, K. (1977). ''Anatomy of seed plants''. John Wiley and Sons, New York. Numerous dry s are attached to the outside of the fruit-flesh, (see image); they appear to be seeds but each is actually an ovary of a flower, with a seed inside. Schizocarps are dry fruits, though some appear to be fleshy. They originate from syncarpous ovaries but do not actually dehiscence (botany), dehisce; rather, they split into segments with one or more seeds. They include a number of different forms from a wide range of families, including carrot, parsnip, parsley, cumin.
Aggregate fruitsFile:Lilyfruit.jpg, upright 1.02, ''Lilium'' unripe capsule fruit; an aggregate fruit. An aggregate fruit is also called an aggregation, or ''etaerio''; it develops from a single flower that presents numerous simple pistils (see graphic of raspberry pistils). Each pistil contains one ; together they form a fruitlet. The ultimate (fruiting) development of the aggregation of pistils is called an aggregate fruit, etaerio fruit, or simply an etaerio. Different types of aggregate fruits can produce different etaerios, such as achenes, drupelets, follicles, and berries. For example, the Ranunculaceae species, including ''Clematis'' and ''Ranunculus'', produces an etaerio of s; ''Rubus'' species, including raspberry: an etaerio of drupelets; ''Calotropis'' species: an etaerio of follicles fruit; ''Annona'' species: an etaerio of berries. Some other broadly recognized species and their etaerios (or aggregations) are: * Teasel; fruit is an aggregation of cypsela (botany), cypselas. * tuliptree#Description, Tuliptree; fruit is an aggregation of samara (fruit), samaras. * Magnolia and peony#Morphology, peony; fruit is an aggregation of follicles. * liquidambar#Species, American sweet gum; fruit is an aggregation of capsules. * Platanus occidentalis#Description, Sycamore; fruit is an aggregation of achenes. The ''raspberry''; its pistils are called ''drupelets'' because each pistil is like a small attached to the receptacle. In some bramble fruits such as blackberry the receptacle, an accessory part, elongates and then develops as part of the fruit, making the blackberry an ''#Accessory fruit, aggregate-accessory'' fruit. The is also an aggregate-accessory fruit, of which the seeds are contained in the s. Notably in all these examples, the fruit develops from a single flower, with numerous pistils.
Multiple fruitsA multiple fruit is formed from a cluster of flowers, (a 'multiple' of flowers) —also called an ''inflorescence''. Each ('smallish') flower produces a single fruitlet, which, as all develop, all merge into one mass of fruit. Examples include pineapple, ficus, fig, mulberry, Osage orange, breadfruit. An inflorescence (a cluster) of white flowers, called a head, is produced first. After Fertilization#Fertilisation in plants, fertilization, each flower in the cluster develops into a drupe; as the drupes expand, they develop as a ''connation, connate'' organ, merging into a multiple fleshy fruit called a ''syncarp''. Progressive stages of multiple flowering and fruit development can be observed on a single branch of the Indian mulberry, or ''noni'', (see image). During the sequence of development, a progression of second, third, and more inflorescences are initiated in turn at the head of the branch or stem.
Accessory fruit formsFor some fruits, some (or all) of the edible parts do ''not'' issue from the ovary; such fruit development can comprise all the pistils and other parts produced from one flower as well as all those produced from many flowers. This form of development is called ''accessory'' fruiting, and it occurs among all three classes of fruit development —simple, aggregate, and multiple. Accessory fruits are frequently designated by the hyphenated term showing both characters; e.g., pineapple is a multiple-accessory fruit.
Table of fleshy fruit examples
Seedless fruitsSeedlessness is an important feature of some fruits of commerce. Commercial cultivars of s and pineapples are examples of seedless fruits. Some cultivars of citrus fruits (especially grapefruit, mandarin oranges, navel ), Mikan, satsumas, table grapes, and of watermelons are valued for their seedlessness. In some species, seedlessness is the result of ''parthenocarpy'', where fruits set without fertilization. Parthenocarpic fruit-set may (or may not) require pollination, but most seedless citrus fruits require a stimulus from pollination to produce fruit. Seedless bananas and grapes are triploids, and seedlessness results from the abortion of the embryonic plant that is produced by fertilization, a phenomenon known as ''stenospermocarpy'', which requires normal pollination and fertilization.
Seed disseminationVariations in fruit structures largely depend on the Biological dispersal, modes of dispersal applied to their seeds. Dispersal is achieved by wind or water, by explosive dehiscence, and by interactions with animals. Some fruits present their outer skins or shells coated with spikes or hooked burrs; these evolved either to deter would-be foragers from feeding on them, or to serve to attach themselves to the hair, feathers, legs, or clothing of animals, thereby using them as dispersal agents. These plants are termed zoochorous; common examples include cocklebur, unicorn plant, and beggarticks, beggarticks (or Spanish needle). By developments of mutual evolution the fleshy produce of fruits typically appeals to hungry animals, such that the seeds contained within are taken in, carried away and later deposited (i.e., Defecation, defecated) at a distance from the parent plant. Likewise, the nutritious, oily kernels of typically motivate birds and squirrels to hoarding, hoard them, burying them in soil to retrieve later during the winter of scarcity; thereby, uneaten seeds are sown effectively under natural conditions to Germination, germinate and grow a new plant some distance away from the parent. Other fruits have evolved wing#In nature, flattened and elongated wings or helicopter, helicopter-like blades, e.g., , maple, and tuliptree. This mechanism increases dispersal distance away from the parent via wind. Other wind-dispersed fruit have tiny "Pappus (flower structure), parachutes", e.g., , Asclepias, milkweed, Tragopogon, salsify. Coconut fruits can float thousands of miles in the ocean, thereby spreading their seeds. Other fruits that can disperse via water are nipa palm and screw pine. Some fruits have evolved propulsive mechanisms that fling seeds substantial distances —(perhaps up to 100 m in the case of the sandbox tree)— via explosive dehiscence or other such mechanisms, (see impatiens and squirting cucumber.
Food usesA cornucopia of fruits —fleshy (simple) fruits from apples to berries to watermelon; dry (simple) fruits including beans and rice, coconuts and carrots; aggregate fruits including strawberries, raspberries, blackberries, pawpaw; multiple fruits such as pineapple, fig, mulberries; (see above re all)— are commercially valuable as human food. They are eaten both fresh and as jams, marmalade and other fruit preserves. They are used extensively in manufactured and processed foods (cakes, cookies, baked goods, flavorings, ice cream, yogurt, canned vegetables, frozen vegetables and meals) and beverages such as fruit juices and alcoholic beverages (brandy, fruit beer, wine). Spices like vanilla, black pepper, paprika, and are derived from berries. Olive, Olive fruit is pressed for olive oil and similar processing is applied to other oil bearing fruits/vegetables. Fruits are also used for socializing and gift-giving in the form of fruit baskets and fruit bouquets. Typically, many botanical fruits —"vegetables" in culinary ''parlance''— (including tomato, green beans, leaf greens, bell pepper, cucumber, eggplant, okra, pumpkin, squash, zucchini) are bought and sold daily in fresh produce markets and greengroceries and carried back to kitchens, at home or restaurant, for preparation of meals.
StorageAll fruits benefit from proper post harvest care, and in many fruits, the plant hormone Ethylene-ripened fruits, ethylene causes ripening. Therefore, maintaining most fruits in an efficient cold chain is optimal for post harvest storage, with the aim of extending and ensuring shelf life.Why Cold Chain for Fruits:
Nutritional valueVarious culinary fruits provide significant amounts of fiber and water, and many are generally high in vitamin C. An overview of numerous studies showed that fruits (e.g., whole apples or whole oranges) are satisfying (filling) by simply eating and chewing them. The dietary fiber consumed in eating fruit promotes satiety, and may help to control body weight and aid reduction of blood cholesterol, a risk factor for cardiovascular diseases. Fruit consumption is under preliminary research for the potential to improve nutrition and affect chronic diseases. Regular consumption of fruit is generally associated with reduced risks of several diseases and functional declines associated with aging.
Food safetyFor food safety, the Centers for Disease Control and Prevention, CDC recommends proper fruit handling and preparation to reduce the risk of food contamination and foodborne illness. Fresh fruits and vegetables should be carefully selected; at the store, they should not be damaged or bruised; and precut pieces should be refrigerated or surrounded by ice. All fruits and vegetables should be rinsed before eating. This recommendation also applies to produce with rinds or skins that are not eaten. It should be done just before preparing or eating to avoid premature spoilage. Fruits and vegetables should be kept separate from raw foods like meat, poultry, and seafood, as well as from utensils that have come in contact with raw foods. Fruits and vegetables that are not going to be cooked should be thrown away if they have touched raw meat, poultry, seafood, or eggs. All cut, peeled, or cooked fruits and vegetables should be refrigerated within two hours. After a certain time, harmful bacteria may grow on them and increase the risk of foodborne illness.
AllergiesFruit allergies make up about 10 percent of all food related allergies.
Nonfood usesBecause fruits have been such a major part of the human diet, various cultures have developed many different uses for fruits they do not depend on for food. For example: * Bayberry fruits provide a wax often used to make candles; * Many dry fruits are used as decorations or in dried flower arrangements (e.g., annual honesty, cotoneaster, Nelumbo, lotus, , unicorn plant, and ). Ornamental trees and shrubs are often cultivated for their colorful fruits, including beautyberry, cotoneaster, holly, pyracantha, skimmia, and viburnum. * Fruits of opium poppy are the source of opium, which contains the drugs codeine and morphine, as well as the biologically inactive chemical theabaine from which the drug oxycodone is synthesized. * Osage orange fruits are used to repel cockroaches. * Many fruits provide natural dyes (e.g., , mulberry, sumac, and ). * Dried gourds are used as bird houses, cups, decorations, dishes, musical instruments, and water jugs. * Pumpkins are carved into Jack-o'-lanterns for Halloween. * The spiny fruit of burdock or cocklebur inspired the invention of Velcro. * Coir fiber from shells is used for brushes, doormats, floor tiles, insulation, mattresses, sacking, and as a growing medium for container plants. The shell of the coconut fruit is used to make bird houses, bowls, cups, musical instruments, and souvenir heads. * Fruit is often a subject of still life paintings.
See also* Fruit tree * Fruitarianism * List of culinary fruits * List of foods * List of fruit dishes
Further reading* Gollner, Adam J. (2010). ''The Fruit Hunters: A Story of Nature, Adventure, Commerce, and Obsession''. Scribner. * Watson, R. R., and Preedy, V.R. (2010, eds.). ''Bioactive Foods in Promoting Health: Fruits and Vegetables''. Academic Press.