Chaff is the dry, scaly protective casings of the seeds of cereal grain, or similar fine, scaly plant material such as scaly parts of flowers, or finely chopped straw. Chaff is indigestible by humans, but livestock can eat it and in agriculture it is used as livestock fodder, or is a waste material ploughed into the soil or burned. "Chaff" comes from Middle English chaf, from Old English ceaf, related to Old High German cheva, "husk". In grasses, the ripe seed is surrounded by thin, scaly bracts, forming a dry husk around the grain. Once it is removed it is referred to as chaff. In wild cereals and in the primitive domesticated einkorn and spelt wheats, the husks enclose each seed tightly. Before the grain can be used, the husks must be removed; the process of loosening the chaff from the grain so as to remove it is called threshing – traditionally done by milling or pounding. Separating remaining loose chaff from the grain is called winnowing – traditionally done by tossing the grain up into a light wind which blows the lighter chaff away.
This method utilizes a broad, plate-shaped basket or similar receptacle to hold and collect the winnowed grain as it falls back down. Domesticated grains such as durum wheat and common wheat have been bred to have chaff, removed; these varieties are known as naked. Chaff should not be confused with bran, finer scaly material, part of the grain itself. Chaff is made by chopping straw into short lengths, using a machine called a chaff cutter. Like grain chaff this is used as animal feed, is a way of turning coarse fodder into a form more palatable to livestock. In botany, chaff refers to the thin receptacular bracts of many species in the sunflower family Asteraceae and related families, they are modified scale-like leaves surrounding single florets in the flower-head. Chaff as a waste product from grain processing leads to a metaphorical use of the term, to refer to something seen as worthless; this is used in the expression "to separate the wheat from the chaff" from Matthew 3:12 which says: Whose fan is in his hand, he will purge his floor, gather his wheat into the garner.
Compare the "Parable of the Tares", which refers to a mixture of wheat and tares. Another example is in Psalm 1:4 of the Bible, which says: The ungodly are not so: but are like the chaff which the wind driveth away. Hungarian engineer László Schremmer has discovered that by the use of chaff-based filters it is possible to reduce the arsenic content of water to 3 microgram/litre; this is important in areas where the potable water is provided by filtering the water extracted from the underground aquifer. Bran Biomass Combine harvester Rice hulls Rice huller Threshing Threshing machine Winnowing
Aleurone is a protein found in protein granules of maturing seeds and tubers. The term describes one of the two major cell types of the endosperm, the aleurone layer; the aleurone layer is the outermost layer of the endosperm, followed by the inner starchy endosperm. This layer of cells is sometimes referred to as the peripheral endosperm, it lies between the hyaline layer of the endosperm. Unlike the cells of the starchy endosperm, aleurone cells remain alive at maturity. Aleurone proteins can have two different morphological features and heterogeneous; the homogenous aleurone consists of similar protein bodies while the heterogeneous aleurone consists of granules of different shapes and types of proteins covered with a membrane. The aleurone layer surrounds the endosperm tissue of grass seeds and is morphologically and biochemically distinct from it. Starchy endosperm cells are large, irregularly shaped cells and contain starch grains while aleurone cells are cuboidal in shape and contain aleurone grains.
In most cultivated cereals the aleurone is single-layered, whereas barley has a multicellular aleurone layer. Thick primary cell walls enclose and protect the aleurone cells; the aleurone layer is important for the mature plant. The aleurone tissue accumulates large quantities of oils and lipids that are useful during seed development, it is a site of mineral storage and in some species, functions in seed dormancy. The aleurone may express several pathogen-protective proteins including PR-4. Aleurone serves as the most dietarily beneficial fraction in many brans. In addition, the aleurone tissue contains many protein-storing vacuoles known as protein bodies. In cereals with starchy endosperm, the aleurone contains about 30% of the kernel's proteins. In multicolored corn, anthocyanin pigments in the aleurone layer give the kernels a dark, bluish-black color; the development of the aleurone layer involves several periclinal, anticlinal cell divisions and several steps of genetic regulation. The dek1 gene and crinkly4 kinase both function as positive regulators of aleurone cell fate.
The normal dek1 gene is needed in order to receive and respond to positional cues that determine the fate of aleurone cells during development. Mutants of the dek1 gene block the formation of aleurone and cause the cells to develop as starchy endosperm cells instead of aleurone cells; this causes the seed to lack an aleurone layer. This mutation is caused by the insertion of a Mu transposon into the dek1 gene, causing it to function incorrectly. However, this transposon may sometimes remove itself from the gene, restoring the function of dek1. Experiments in this area have helped demonstrate that the cues that determine aleurone positioning are still present in the stages of development, the aleurone cells still respond to these cues. Similar to the dek1 mutation, genes with a mutation in the cr4 gene cause a switch in the fate of aleurone cells; the cr4 gene codes for a receptor kinase and so is involved in signal transduction pathways involving the fate of aleurone cells. Plants with a mutated cr4 gene produce crinkled leaves.
In addition, several hormones influence the development of the aleurone layer, including auxin, abscisic acid, gibberellin. Auxin and cytokinin play a role in the earlier stages of aleurone development; the maturation of aleurone is promoted by ABA while germination is promoted by GA. The aleurone layer performs a variety of functions to help maintain proper development of the seed. One example of this is maintaining a low pH in the apoplast. In cereals, the aleurone layer releases organic and phosphoric acids in order to keep the pH of the endosperm between a pH of 3.5 and 4. In barley, the aleurone layer releases nitrite into the starchy endosperm and apoplast under anaerobic conditions. In addition, although the function is unclear, a certain class of hemoglobins is present in the outer layer of living cells including the aleurone tissue in barley and rice seeds. During seed germination, the plant embryo produces the hormone gibberellin which triggers the aleurone cells to release α-amylase for the hydrolysis of starch and storage proteins into the endosperm.
Evidence that G-proteins play a role in the gibberellin signaling events has been obtained. The breakdown of the starchy endosperm supplies sugars to drive the growth of roots and the acrospire; this release of amylase is considered to be the most important and sole function of the aleurone layer. This effect is inhibited by the plant hormone abscisic acid. After completing this function, the aleurone cells in the developing seed undergo apoptosis. Experiments conducted in the 1960s confirmed that in order for the aleurone layer to secrete starch-degrading enzymes, the embryo must be present. Following removal of the embryo, starch-degrading enzymes were not released and no degradation of the starch tissue occurred; the gibberellin effect on the aleurone is used in brewing in the production of barley malt where treatment ensures that a batch of barley seeds will germinate evenly. "Aleurone". New International Encyclopedia. 1905
Pickling is the process of preserving or extending the lifespan of food by either anaerobic fermentation in brine or immersion in vinegar. In East Asia, vinaigrette is used as a pickling medium; the pickling procedure affects the food's texture and flavor. The resulting food is called a pickle, or, prefaced with pickled. Foods that are pickled include vegetables, meats and eggs. A distinguishing characteristic is a pH of 4.6 or lower, sufficient to kill most bacteria. Pickling can preserve perishable foods for months. Antimicrobial herbs and spices, such as mustard seed, cinnamon or cloves, are added. If the food contains sufficient moisture, a pickling brine may be produced by adding dry salt. For example and Korean kimchi are produced by salting the vegetables to draw out excess water. Natural fermentation at room temperature, by lactic acid bacteria, produces the required acidity. Other pickles are made by placing vegetables in vinegar. Like the canning process, pickling does not require that the food be sterile before it is sealed.
The acidity or salinity of the solution, the temperature of fermentation, the exclusion of oxygen determine which microorganisms dominate, determine the flavor of the end product. When both salt concentration and temperature are low, Leuconostoc mesenteroides dominates, producing a mix of acids and aroma compounds. At higher temperatures Lactobacillus plantarum dominates, which produces lactic acid. Many pickles start with Leuconostoc, change to Lactobacillus with higher acidity; the exact origins of pickling are unknown, but it may have begun in the area of Mohenjo Daro, in the northwest of the Indian subcontinent, about 2400 B. C. Pickling was used as a way to preserve food for out-of-season use and for long journeys by sea. Salt pork and salt beef were common staples for sailors before the days of steam engines. Although the process was invented to preserve foods, pickles are made and eaten because people enjoy the resulting flavors. Pickling may improve the nutritional value of food by introducing B vitamins produced by bacteria.
The term pickle is derived from the Dutch word pekel. In the U. S. and Canada, sometimes Australia and New Zealand, the word pickle alone always refers to a pickled cucumber, except when it is used figuratively. It may refer to other types of pickles such as "pickled onion", "pickled cauliflower", etc. In the UK, pickle, as in a "cheese and pickle sandwich", may refer to Ploughman's pickle, a kind of chutney. South Asia has a large variety of pickles, which are made from varieties of mango, lime, goongura and Indian gooseberry, chilli. Vegetables such as eggplant, cauliflower, bitter gourd, green tamarind, garlic and citron are occasionally used; these fruits and vegetables are mixed with ingredients like salt and vegetable oils and are set to mature in a moistureless medium. In Pakistan, pickles are come in a variety of flavors. A popular item is the traditional mixed Hyderabadi pickle, a common delicacy prepared from an assortment of fruits and vegetables blended with selected spices. Although the origin of the word is ambiguous, the word āchār is considered to be of Persian origin.
Āchār in Persian is defined as ‘powdered or salted meats, pickles, or fruits, preserved in salt, honey, or syrup.'In Sri Lanka, achcharu is traditionally prepared from carrots and ground dates that are mixed with mustard powder, ground pepper, crushed ginger and vinegar, left to sit in a clay pot. Singapore and Malaysian pickles, called acar, are made out of cucumber, bird's eye chilies, shallots, these items being seasoned with vinegar and salt. Fruits, such as papaya and pineapple, are sometimes pickled. In the Philippines, pickling was traditionally done in earthen jars and is known as buro or binuro. Pickling was a common method of preserving food throughout the archipelago before the advent of refrigeration, but its popularity is now confined to vegetables and fruits. Achara remains popular as the Philippine localization of the Malay acar, is made out of green papaya and shallots, seasoned with cloves of garlic and vinegar. Pickled unripe mangoes or burong mangga, unripe tomatoes, jicama, bitter gourd and other fruit and vegetables still retain their appeal.
Siling labuyo, sometimes with garlic and red onions, is pickled in bottled vinegar and is a staple condiment in Filipino cuisine. In Vietnamese cuisine, vegetable pickles are called dưa chua. Dưa chua or dưa góp is made from a variety of fruits and vegetables, including cà pháo, Napa cabbage, carrots, papaya and sung. Dưa chua made from carrots and radishes are added to bánh mì sandwiches. Dưa cải muối is made by sun-drying vegetables such as cải bẹ xanh and bok choy. Nhút mít is a specialty of Nghệ Hã Tĩnh provinces made from jackfruit. In Burma, tea leaves are pickled to produce lahpet, which has strong cultural importance. China is home to a huge variety of pickled vegetables, including radish, baicai (Chinese cabbage
Nukazuke are a type of Japanese pickle, made by fermenting vegetables in rice bran. Any edible vegetable may be pickled through this technique, though traditional varieties include eggplant, Japanese radish and cucumber; the taste of nuka pickles can vary from pleasantly tangy to sour and pungent. These pickles retain their crispness which adds to their popularity. Fish nukazuke is common in the north part of Japan. Sardine, Japanese horse mackerel are used; some people pickle meat in nuka-bed. The nuka-bed is traditionally kept in a wooden crock but ceramic crocks or plastic buckets are common. Many Japanese households have their own nukazuke crocks which are faithfully stirred by hand every day. Due to varying methods and recipes, flavors vary not only from region to region but from household to household. Pickles are an important staple of Japanese cuisine, nukazuke are one of the most popular kinds, they are eaten at the end of a meal and are said to aid in digestion. The lactobacillus in nukazuke pickles may be a beneficial supplement to the intestinal flora.
They are high in vitamin B1. Rice bran is first mixed in a crock with salt, kombu seaweed, water; some recipes call for ginger, beer or wine. The resultant mash, called nukamiso or nukadoko, has a consistency comparable to wet sand or cooked grits. Vegetables, apple peels, or persimmon peels are added to the nuka-bed every day for at least a few days until a fermenting culture has been established. At this point nuka-bed is ‘live,’ meaning that it contains a culture of active single-celled organisms lactobacilli and yeast. Although nukazuke can be made from scratch, a bit of well seasoned nuka from an older batch is used to ‘seed’ a fresh batch. Unless an established nuka sample is used to seed a fresh batch, the ubiquitous lactic acid-producing colonies crucial to the fermentation process must come from sources such as the skin of the starter vegetables or from human hands. Once the fermenting cultures have been established the nuka-bed develops a complex unique aroma that may be described as anything from "yeasty" to "earthy".
At this point the starter vegetables are discarded and pickling vegetables are buried in the bed for as little as a few hours to as long as several months for strong flavor. Some sources recommend a maximum pickling time of one month. Others suggest. Unpleasant smells such as a "sour" or "stinky" aroma may indicate a problem with the nuka-bed; because the process depends on colonies of live organisms and smells can vary from day to day and the fermenting process slows in colder weather. When ready, nukazuke pickles are removed from the bed, washed in cool clean water and served as a side to savory meals; the nuka-bed must be stirred well daily to keep it from becoming putrescent, moldy or infested with vermin. The acidity, salt content and oxygenation provided by daily stirring keeps toxic microbes from growing in the bed, it is universally recommended. Sometimes weights made of metal, stone or jugs of water are used the keep the nuka-bed under pressure, drawing water from the vegetables and speeding fermentation.
Nuka-beds are known to acquire subtle flavors from the surrounding environment and thus should not be stored in musty areas. Additional amounts of rice bran and salt are added from time to time, some recommend discarding portions of the old nuka to make way for the new. Water is provided by the vegetables buried in the bed. With proper maintenance nuka-beds can be kept indefinitely and are passed down from generation to generation. Old nuka-beds are valued for their nuanced flavor. Takuan is one variation of nukazuke. Traditional takuan uses sun-dried daikon, mass production takuan are prepared with sugar to cut pickling time. Ginger, orange seeds, persimmon peels or apple peels can be added to the nuka-bed for flavor. Dried chili-peppers and/or fresh garlic are added either for flavor, to keep the bed from becoming wormy, or to keep fermentation in check; when rice bran cannot be found, alternatives such as wheat bran or cornflakes have been reported to work well. Takuan – A pickled preparation of daikon radish Pickled radish – A radish dish served with Korean fried chicken Katz, Sandor Ellix.
Wild fermentation, Chelsea Green, 2003. ISBN 1-931498-23-7 Tsuji, Shizuo. Japanese cooking: a simple art, Kodansha International, 1980. ISBN 0-87011-399-2 How to Make Nukazuke: Nukadoko Pickling Bed, February 15, 2009 by Kyoto Foodie Nukazuke: Japanese Rice Bran Pickles, April 24, 2009, Wandering Spoon https://web.archive.org/web/20031128033242/http://ytoshi.cool.ne.jp/best_friends32/study/cl/food/pickles/pickles1.htm http://www.theblackmoon.com/Jfood/ftsuke.html http://joi.ito.com/archives/1999/04/04/nukamiso_guide_version_14.html http://joi.ito.com/archives/2005/06/20/nukamiso_redux.html
Millets are a group of variable small-seeded grasses grown around the world as cereal crops or grains for fodder and human food. Millets are important crops in the semiarid tropics of Asia and Africa, with 97% of millet production in developing countries; the crop is favored due to its productivity and short growing season under dry, high-temperature conditions. Millets are indigenous to many parts of the world; the most grown millet is pearl millet, an important crop in India and parts of Africa. Finger millet, proso millet, foxtail millet are important crop species. Millets may have been consumed by humans for about 7,000 years and had "a pivotal role in the rise of multi-crop agriculture and settled farming societies". Millets are small-grained, warm-weather cereals belonging to the grass family, they are tolerant of drought and other extreme weather conditions and have a similar nutrient content to other major cereals. The different species of millets are not closely related. All are members of the family Poaceae but can belong to different tribes or subfamilies.
The most cultivated millets are in bold and marked with an *. Eragrostideae tribe in the subfamily Chloridoideae: *Eleusine coracana: Finger millet Eragrostis tef: Teff – not considered to be a millet. Paniceae tribe in the subfamily Panicoideae: Genus Panicum: *Panicum miliaceum: Proso millet *Panicum sumatrense: Little millet *Pennisetum glaucum: Pearl millet *Setaria italica: Foxtail millet, Italian millet, panic Genus Digitaria – of minor importance as crops. Digitaria exilis: known as white fonio, fonio millet, hungry rice or acha rice. Digitaria iburua: Black fonio Digitaria compacta: Raishan, cultivated in the Khasi Hills of northeast India Digitaria sanguinalis: Polish millet Genus Echinochloa: Collectively, the members of this genus are called barnyard grasses or barnyard millets. Other common names to identify these seeds include Jhangora, Samo seeds or Morio / Mario / Moraiaya seeds. Echinochloa esculenta: Japanese barnyard millet Echinochloa frumentacea: Indian barnyard millet known as Sawa millet, Kodisama in Andhra Pradesh and Kuthirai vaali in Tamil Nadu and Bhagar or Varai in Maharashtra), Echinochloa stagnina: Burgu millet Echinochloa crus-galli: Common barnyard grass.
Paspalum scrobiculatum: Kodo millet Brachiaria deflexa: Guinea millet Urochloa ramosa: Browntop millet Andropogoneae tribe in the subfamily Panicoideae: *Sorghum bicolor: Sorghum - considered a separate cereal, but sometimes known as Great millet Coix lacryma-jobi: Job's tears known as adlay millet. Chinese legends attribute the domestication of millet to the legendary Emperor of China. Millets have been mentioned in some of the oldest extant Yajurveda texts, identifying foxtail millet, Barnyard millet and black finger millet, indicating that millet consumption was common, dating to 4500 BCE, during the Indian Bronze Age. Common millet is believed to have been the first domesticated millet dating back about 10,300 years before the present. Specialized archaeologists called palaeoethnobotanists, relying on data such as the relative abundance of charred grains found in archaeological sites, hypothesize that the cultivation of millets was of greater prevalence in prehistory than rice in northern China and Korea.
Millets formed important parts of the prehistoric diet in Indian, Chinese Neolithic and Korean Mumun societies. Broomcorn and foxtail millet were important crops beginning in the Early Neolithic of China. For example, some of the earliest evidence of millet cultivation in China was found at Cishan. Cishan dates for common millet husk phytoliths and biomolecular components have been identified around 8300–6700 BCE in storage pits along with remains of pit-houses and stone tools related to millet cultivation. Evidence at Cishan for foxtail millet dates back to around 6500 BCE. A 4,000-year-old well-preserved bowl containing well-preserved noodles made from foxtail millet and broomcorn millet was found at the Lajia archaeological site in China. Millet was growing wild in Greece as early as 3000 BCE, bulk storage containers for millet have been found from the Late Bronze Age in Macedonia and northern Greece. Hesiod describes that "the beards grow round the millet, which men sow in summer." And millet is listed along with wheat in the 3rd century BCE by Theophrastus in his "Enquiry into Plants".
Palaeoethnobotanists have found evidence of the cultivation of millet in the Korean Peninsula dating to the Middle Jeulmun pottery period. Millet continued to be an important element in the intensive, multicropping agriculture of the Mumun pottery period in Korea. Millets and their wild ancestors, such as barnyard grass and panic grass, were cultivated in Japan during the Jōmon period some time after 4000 BCE. Asian varieties of millet made their way from China to the Black Sea region of Europe by 5000 BCE; the cultivation of common millet as the earliest dry crop in East Asia has been attributed to its resistance to drought, this has been suggested to have aided its spread. Pearl millet was domesticated in the Sahel region of West Africa, where its wild ancestors are found. Evidence for the cultivation of pearl millet in Mali dates back to 2500 BCE, pearl millet is found in the Indian subcontinent by 2300 BCE. Finger millet is o
Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere. There are two main types of boiling: nucleate boiling where small bubbles of vapour form at discrete points, critical heat flux boiling where the boiling surface is heated above a certain critical temperature and a film of vapor forms on the surface. Transition boiling is an unstable form of boiling with elements of both types; the boiling point of water is 100 °C or 212 °F but is lower with the decreased atmospheric pressure found at higher altitudes. Boiling water is used as a method of making it potable by killing microbes; the sensitivity of different micro-organisms to heat varies, but if water is held at 70 °C for ten minutes, many organisms are killed, but some are more resistant to heat and require one minute at the boiling point of water. Boiling is used in cooking.
Foods suitable for boiling include vegetables, starchy foods such as rice and potatoes, eggs, "meats", sauces and soups. As a cooking method, it is suitable for large-scale cookery. Tough meats or poultry can be given a long, slow cooking and a nutritious stock is produced. Disadvantages include loss of water-soluble minerals. Commercially prepared foodstuffs are sometimes packed in polythene sachets and sold as "boil-in-the-bag" products. Nucleate boiling is characterized by the growth of bubbles or pops on a heated surface, which rises from discrete points on a surface, whose temperature is only above the liquids. In general, the number of nucleation sites are increased by an increasing surface temperature. An irregular surface of the boiling vessel or additives to the fluid can create additional nucleation sites, while an exceptionally smooth surface, such as plastic, lends itself to superheating. Under these conditions, a heated liquid may show boiling delay and the temperature may go somewhat above the boiling point without boiling.
As the boiling surface is heated above a critical temperature, a film of vapor forms on the surface. Since this vapor film is much less capable of carrying heat away from the surface, the temperature rises rapidly beyond this point into the transition boiling regime; the point at which this occurs is dependent on the characteristics of boiling fluid and the heating surface in question. Transition boiling may be defined as the unstable boiling, which occurs at surface temperatures between the maximum attainable in nucleate and the minimum attainable in film boiling; the formation of bubbles in a heated liquid is a complex physical process which involves cavitation and acoustic effects, such as the broad-spectrum hiss one hears in a kettle not yet heated to the point where bubbles boil to the surface. If a surface heating the liquid is hotter than the liquid film boiling will occur, where a thin layer of vapor, which has low thermal conductivity, insulates the surface; this condition of a vapor film insulating the surface from the liquid characterizes film boiling.
As a method of disinfecting water, bringing it to its boiling point at 100 °C, is the oldest and most effective way since it does not affect the taste, it is effective despite contaminants or particles present in it, is a single step process which eliminates most microbes responsible for causing intestine related diseases. Water's boiling point rests at around 100.0 degrees Celsius, when at an elevation of 0. In places having a proper water purification system, it is recommended only as an emergency treatment method or for obtaining potable water in the wilderness or in rural areas, as it cannot remove chemical toxins or impurities; the elimination of micro-organisms by boiling follows first-order kinetics—at high temperatures, it is achieved in less time and at lower temperatures, in more time. The heat sensitivity of micro-organisms varies, at 70 °C, Giardia species can take ten minutes for complete inactivation, most intestine affecting microbes and E. coli take less than a minute. Boiling does not ensure the elimination of all micro-organisms.
Thus for human health, complete sterilization of water is not required. The traditional advice of boiling water for ten minutes is for additional safety, since microbes start getting eliminated at temperatures greater than 60 °C and bringing it to its boiling point is a useful indication that can be seen without the help of a thermometer, by this time, the water is disinfected. Though the boiling point decreases with increasing altitude, it is not enough to affect the disinfecting process. Boiling is the method of cooking food in boiling water or other water-based liquids such as stock or milk. Simmering is gentle boiling; the boiling point of water is considered to be 100 °C or 212 °F. Pressure and a change in the composition of the liquid may alter the boiling point of the liquid. For this reason, high elevation cooking takes longer since boiling point is a function of atmospheric pressure. In Denver, Colorado, USA, at an elevation of about one mile, water boils at 95 °C or 203 °F. Depending on the type of food and the elevation, the boiling water may not be hot enough to cook the food properly.
Fruit anatomy is the plant anatomy of the internal structure of fruit. Fruits are ovaries of one or more flowers. In fleshy fruits, the outer layer is the pericarp, the tissue that develops from the ovary wall of the flower and surrounds the seeds, but in some pericarp fruits, the edible portion is not derived from the ovary. For example, in the fruit of the ackee tree the edible portion is an aril, in the pineapple several tissues from the flower and stem are involved; the outer covering of a seed is tough. Fruits are found in three main anatomical categories: simple fruits, aggregate fruits, multiple fruits. Aggregate fruits contain many ovaries or fruitlets. Examples include blackberries. Multiple fruits are formed from the fused ovaries of multiple flowers or inflorescence. An example of multiple fruits are the fig and the pineapple. Simple fruit may contain one or many seeds, they can be either dry. In fleshy fruit, during development, the pericarp and other accessory structures become the fleshy portion of the fruit.
The types of fleshy fruits are berries and drupes. In berries, the entire pericarp is fleshy but this excludes the exocarp which acts as more as a skin. There are berries that are known as pepo, a type of berry with an inseparable rind, or hesperidium, which has a separable rind. An example of a pepo is the cucumber and a lemon would be an example of a hesperidium; the fleshy portion of the pomes is developed from the floral tube and like the berry most of the pericarp is fleshy but the endocarp is cartilaginous, an apple is an example of a pome. Lastly, drupes are known for being one seeded with a fleshy mesocarp, an example of this would be the peach. However, there are fruits were the fleshy portion is developed from tissues that are not the ovary, such as in the strawberry; the edible part of the strawberry is formed from the receptacle of the flower. Due, to this difference the strawberry is known as an accessory fruit. There is a shared method of seed dispersal within fleshy fruits; these fruits depend on animals to eat the fruits and disperse the seeds in order for their populations to survive.
Dry fruits develop from the ovary but unlike the fleshy fruits they do not depend on the mesocarp but the endocarp for seed dispersal. Dry fruits depend more like wind and water. Dry fruits' seeds can perform pod shattering, which involve the seed being ejected from the seed coat by shattering it; some dry fruits are able to perform wisteria, an extreme case where there is an explosion of the pod, resulting the seed to be dispersed over long distances. Like fleshy fruits, dry fruits can depend on animals to spread their seeds by adhering to animal's fur and skin, this is known as epizoochory. Types of dry fruits include achenes, follicles or nuts. Dry fruits can be separated into dehiscent and indehiscent fruits. Dry dehiscent fruits are described as a fruit where the pod has an increase in internal tension to allow seeds to be released; these include the sweet pea, alfalfa, mustard and poppy. Dry indehiscent fruit differ in that they do not have this mechanism and depend on physical forces. Examples of species indehiscent fruit are sunflower seeds and dandelions.
There is a wide variety in the structures of fruit across the different species of plants. Evolution has selected for certain traits in plants; this diversity arose through the selection of advantageous methods for seed protection and dispersal in different environments. It is known. A study looking at the Rubiaceae family found that within the family, fleshy fruits had evolved independently at least 12 times; this means that fleshy fruits were not passed on to following generations but that this form of fruit was selected for in different species. This may imply that fleshy fruit is a favorable and beneficial trait because not only does it disperse the seeds, but it protects them. There is a variety of dispersal methods that are used by different plants; the origins of these modes of dispersal have been found to be a more recent evolutionary change. Of the methods of dispersal, the plants that use animals have not changed in many ways from the original trait. Due to this, it may be assumed that animal dispersal is an efficient form of dispersal, however there has been no evidence that it increases dispersal distances.
Therefore, the question remains. It has been found, that simple changes within developmental regulatory genes can cause large alterations within the anatomical structure of the fruit. Without knowing the mechanism involved in the biodiversity of fruit, it is clear that this diversity is important to the continuation of plant populations. In berries and drupes, the pericarp forms the edible tissue around the seeds. In other fruits such as Citrus stone fruits only some layers of the pericarp are eaten. In accessory fruits, other tissues develop into the edible portion of the fruit instead, for example the receptacle of the flower in strawberries. In fleshy fruits, the pericarp is made up of three distinct layers: the epicarp, the outermost layer. In a citrus fruit, the epicarp and mesocarp make up the peel. In dry fruits, the layers of the pericarp are not cle