Husk

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Husk of Corylus colurna (Turkish Hazel), containing 7 nuts Involucre d'un noisetier de Bysance.jpg
Husk of Corylus colurna (Turkish Hazel), containing 7 nuts

Husk (or hull) in botany is the outer shell or coating of a seed. In the United States, the term husk often refers to the leafy outer covering of an ear of maize (corn) as it grows on the plant. Literally, a husk or hull includes the protective outer covering of a seed, fruit, or vegetable.

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It can also refer to the exuvia of insects or other small animals left behind after moulting.

The term husk dates to c.14, it is probably based on Middle Dutch word huusken meaning 'little house', which is derived from hūs meaning house. [1]

In cooking, hull can also refer to other waste parts of fruits and vegetables, notably the cap or sepal of a strawberry. [2]

Grains such as wheat and barley have husks. The grains are the entire seed of a plant. The seed of a grain (which the grain industry calls a “kernel”) is made up of three key edible parts – the bran, the germ, and the endosperm – which are all protected by an inedible husk that protects the kernel from damage by sunlight, pests, water and disease. [3]

Tree husks

In Hazel trees, the nut is surrounded by a short leafy husk (which is technically an involucre). This leaf-like husk encloses most of the nut. It starts off green and will fade to brown at the end of the season. Usually, the ripe nut falls out of (or can be separated from) the husk some 7–8 months after pollination has occurred. [4]

In some places, both shells and the husks of walnuts ( Juglans regia L.) which are produced as waste crops during the fruit harvesting and processing, [5] are sometimes burned as fuel for heating purposes. [6] In 2019, it has been demonstrated that the walnut green husk could be valued as a source of different natural bio-active compounds with excellent antioxidant and antimicrobial properties. [7] [8] As well as cosmetic uses. [9] An organic compound Naphthalenone, (derivative of Naphthalene) is found in green walnut husks of Juglans mandshurica Maxim. for various uses. [10] Juglans nigra , black walnut, husks have antioxidant potential. [11] Confusingly, Walnut husks are also called hulls as well. [12] [13] Rhagoletis juglandis , also known as the 'walnut husk fly' is a common pest of walnuts. The larvae are small and live under the surface of the husk of the walnut. They cause damage to the fruit and husks which then become difficult to remove. The husk fly also infests ripe apricot and peach fruits, usually if infested walnuts are located within flying distance. [14]

Some fruit shell and hull derived bio-adsorbents have also been used for wastewater treatment purposes. For example, the almond hull and shell have been used to remove metals such as Pb, Cd, and Co in various quantities. [15] Iranian almond ( Prunus amygdalus L.) hulls have antioxidant and anti-radical properties. [16]

The coconut husk and shells can be used for fuel and are a source of charcoal. [17] In Thailand, the coconut husk is used as a potting medium to produce healthy forest tree saplings. A dried half coconut shell with husk can be used to buff floors. It is known as a bunot in the Philippines and simply a "coconut brush" in Jamaica. Coir, also called coconut fibre, is a natural fibre extracted from the outer husk of coconut. [18]

Husking and dehulling

Corn being husked in the yard of a Dungan farmer in Kyrgyzstan E8025-Milyanfan-corn-huskers.jpg
Corn being husked in the yard of a Dungan farmer in Kyrgyzstan

Husking of corn is the process of removing its outer layers, leaving only the cob or seed rack of the corn. Dehulling is the process of removing the hulls (or chaff) from beans and other seeds. This is sometimes done using a machine known as a huller. To prepare the seeds to have oils extracted from them, they are cleaned to remove any foreign objects. Next, the seeds have their hulls, or outer coverings, or husk, removed. There are three different types of dehulling systems that can be used to process soybeans: Hot dehulling, warm dehulling and cold dehulling. Hot dehulling is the system offered in areas where beans are processed directly from the field. Warm dehulling is often used by processors who import their soybeans. Cold dehulling is used in plants that have existing drying and conditioning equipment, but need to add dehulling equipment to produce high protein meal. The different dehulling temperature options are for different types of production, beans and preparation equipment.[ citation needed ] [19]

A woman manually dehusking corn in Malawi. People working in subsistence agricultural settings tend not to have the mechanization of processing practices to reduce the labor. In many societies, this labor falls to family members such as women, who make up the majority of farmers working in smallholdings. Africa Food Security 11 (10665081134).jpg
A woman manually dehusking corn in Malawi. People working in subsistence agricultural settings tend not to have the mechanization of processing practices to reduce the labor. In many societies, this labor falls to family members such as women, who make up the majority of farmers working in smallholdings.

In third-world countries, husking and dehulling is still often done by hand using a large mortar and pestle. These are usually made of wood, and operated by one or more people. [20]

The husk is biodegradable and may be composted. [21]

See also

Related Research Articles

<span class="mw-page-title-main">Almond</span> Species of nut

The almond is a species of tree from the genus Prunus. Along with the peach, it is classified in the subgenus Amygdalus, distinguished from the other subgenera by corrugations on the shell (endocarp) surrounding the seed.

<span class="mw-page-title-main">Drupe</span> Fleshy fruit with hard inner layer (endocarp or stone) surrounding the seed

In botany, a drupe is an indehiscent type of fruit in which an outer fleshy part surrounds a single shell of hardened endocarp with a seed (kernel) inside. These fruits usually develop from a single carpel, and mostly from flowers with superior ovaries.

<span class="mw-page-title-main">Sunflower seed</span> Seed of the sunflower (Helianthus annuus)

A sunflower seed is a seed from a sunflower. There are three types of commonly used sunflower seeds: linoleic, high oleic, and sunflower oil seeds. Each variety has its own unique levels of monounsaturated, saturated, and polyunsaturated fats. The information in this article refers mainly to the linoleic variety.

<i>Prunus</i> Genus of trees and shrubs

Prunus is a genus of trees and shrubs in the flowering plant family Rosaceae that includes plums, cherries, peaches, nectarines, apricots, and almonds. The genus has a cosmopolitan distribution, being native to the North American temperate regions, the neotropics of South America, and temperate and tropical regions of Eurasia and Africa, There are about 340 accepted species as of March 2024. Many members of the genus are widely cultivated for their fruit and for decorative purposes. Prunus fruit are drupes, or stone fruits. The fleshy mesocarp surrounding the endocarp is edible while the endocarp itself forms a hard, inedible shell called the pyrena. This shell encloses the seed, which is edible in some species, but poisonous in many others. Besides being eaten off the hand, most Prunus fruit are also commonly used in processing, such as jam production, canning, drying, and the seeds for roasting.

<i>Juglans</i> Genus of trees

Walnut trees are any species of tree in the plant genus Juglans, the type genus of the family Juglandaceae, the seeds of which are referred to as walnuts. All species are deciduous trees, 10–40 metres (33–131 ft) tall, with pinnate leaves 200–900 millimetres (7.9–35.4 in), with 5–25 leaflets; the shoots have chambered pith, a character shared with the wingnuts (Pterocarya), but not the hickories (Carya) in the same family.

<span class="mw-page-title-main">Lentil</span> Species of flowering plant with edible seeds in the family Fabaceae

The lentil is an edible legume. It is an annual plant known for its lens-shaped seeds. It is about 40 cm (16 in) tall, and the seeds grow in pods, usually with two seeds in each.

<span class="mw-page-title-main">Juglandaceae</span> Walnut family of trees

The Juglandaceae are a plant family known as the walnut family. They are trees, or sometimes shrubs, in the order Fagales. Members of this family are native to the Americas, Eurasia, and Southeast Asia.

<span class="mw-page-title-main">Sprouting</span> Practice of germinating seeds to be eaten raw or cooked

Sprouting is the natural process by which seeds or spores germinate and put out shoots, and already established plants produce new leaves or buds, or other structures experience further growth.

<span class="mw-page-title-main">Chaff</span> Protective casings of the seeds of cereal grain

Chaff is dry, scale-like plant material such as the protective seed casings of cereal grains, the scale-like parts of flowers, or finely chopped straw. Chaff cannot be digested by humans, but it may be fed to livestock, ploughed into soil, or burned.

<i>Juglans nigra</i> Species of tree

Juglans nigra, the eastern American black walnut, is a species of deciduous tree in the walnut family, Juglandaceae, native to North America. It grows mostly in riparian zones, from southern Ontario, west to southeast South Dakota, south to Georgia, northern Florida and southwest to central Texas. Wild trees in the upper Ottawa Valley may be an isolated native population or may have derived from planted trees.

<i>Juglans regia</i> Species of tree (walnut)

Juglans regia, the Persian walnut, English walnut, Carpathian walnut, Madeira walnut, or, especially in Great Britain, common walnut, is an Old World walnut tree species native to the region stretching from the Caucasus eastward to the Kashmir region. It is widely cultivated across Asia, Northern America and Europe.

<i>Juglans ailantifolia</i> Species of fruit and plant

Juglans ailantifolia, the Japanese walnut, is a species of walnut native to Japan and Sakhalin. It is a deciduous tree growing to 20 m (66 ft) tall, rarely 30 m (98 ft), and 40–80 cm (16–31 in) stem diameter, with light grey bark. The leaves are pinnate, 50–90 cm (20–35 in) long, with 11–17 leaflets, each leaflet 7–16 cm (2.8–6.3 in) long and 3–5 cm (1.2–2.0 in) broad. The whole leaf is downy-pubescent, and a somewhat brighter, yellower green than many other tree leaves. The male flowers are inconspicuous yellow-green catkins produced in spring at the same time as the new leaves appear. The female flowers have pink/red pistils. The fruit is a nut, produced in bunches of 4–10 together; the nut is spherical, 3–5 cm long and broad, surrounded by a green husk before maturity in mid autumn.

<span class="mw-page-title-main">Rice hull</span> Protective husk of rice grains

Rice hulls or husks are the hard protecting coverings of grains of rice. In addition to protecting rice during the growing season, rice hulls can be put to use as building material, fertilizer, insulation material, or fuel. Rice hulls are part of the chaff of the rice.

<span class="mw-page-title-main">Juglone</span> Chemical produced by walnut trees

Juglone, also called 5-hydroxy-1,4-naphthalenedione (IUPAC) is a phenolic organic compound with the molecular formula C10H6O3. In the food industry, juglone is also known as C.I. Natural Brown 7 and C.I. 75500. It is insoluble in benzene but soluble in dioxane, from which it crystallizes as yellow needles. It is an isomer of lawsone, which is the active dye compound in the henna leaf.

<span class="mw-page-title-main">Rice huller</span> Machine for processing whole rice

A rice huller or rice husker is an agricultural machine used to automate the process of removing the chaff of grains of rice. Throughout history, there have been numerous techniques to hull rice. Traditionally, it would be pounded using some form of mortar and pestle. An early simple machine to do this is a rice pounder. Later even more efficient machinery was developed to hull and polish rice. These machines are most widely developed and used throughout Asia where the most popular type is the Engelberg huller designed by German Brazilian engineer Evaristo Conrado Engelberg in Brazil and first patented in 1885.

Juglans sigillata, also called iron walnut, is the second most cultivated species of walnut tree after the Persian walnut Juglans regia. Commonly distributed in the eastern Himalayas and western China. The tree has been cultivated for its edible nuts, and there are at least 80 authorised or approved cultivars produced after successful implementation of grafting technology.

<i>Juglans hindsii</i> Species of tree

Juglans hindsii, commonly called the Northern California black walnut and Hinds's black walnut, is a species of walnut tree native to the western United States. It is commonly called claro walnut by the lumber industry and woodworkers, and is the subject of some confusion over its being the root stock for English walnut orchard stock.

Rhagoletis juglandis, also known as the walnut husk fly, is a species of tephritid or fruit fly in the family Tephritidae. It is closely related to the walnut husk maggot Rhagoletis suavis. This species of fly belongs to the R. suavis group, which has a natural history consistent with allopatric speciation. The flies belonging to this group are morphologically distinguishable.

<span class="mw-page-title-main">Walnut</span> Nut of any tree of the genus Juglans

A walnut is the edible seed of any tree of the genus Juglans, particularly the Persian or English walnut, Juglans regia. They are accessory fruit because the outer covering of the fruit is technically an involucre and thus not morphologically part of the carpel; this means it cannot be a drupe but is instead a drupe-like nut.

References

  1. ↑ "husk". The Free Dictionary. Retrieved 20 October 2023.
  2. ↑ Splawn, Meghan (1 July 2020). "Here's How to Hull a Strawberry". Kitchn. Retrieved 18 October 2023.
  3. ↑ "What is a Whole Grain? | The Whole Grains Council". wholegrainscouncil.org. Retrieved 20 October 2023.
  4. ↑ "Hazel; Hazelnuts, Filberts, & Cobnuts" . Retrieved 15 October 2023.
  5. ↑ Martinez, M.L.; Labuckas, D.O.; Lamarque, A.L.; Maestri, D.M. (2010). "Walnut (Juglans regia L.): Genetic resources, chemistry, by-products". J. Sci. Food Agric. 90 (12): 1959–1967. doi:10.1002/jsfa.4059. hdl: 11336/14988 . PMID   20586084.
  6. ↑ Jahanban-Esfahlan, Ali; Jahanban-Esfahlan, Rana; Tabibiazar, Mahnaz; Roufegarinejad, Leila; Amarowicz, Ryszard (2020). "Recent advances in the use of walnut (Juglans regia L.) shell as a valuable plant-based bio-sorbent for the removal of hazardous materials". RSC Adv. 10 (12): 7026–7047. Bibcode:2020RSCAd..10.7026J. doi:10.1039/c9ra10084a. PMC   9049835 . PMID   35493920.
  7. ↑ Jahanban-Esfahlan, Ali; Ostadrahimi, Alireza; Tabibiazar, Mahnaz; Amarowicz, Ryszard (August 2019). "A Comprehensive Review on the Chemical Constituents and Functional Uses of Walnut (Juglans spp.) Husk". Int J Mol Sci. 20 (16): 3920. doi: 10.3390/ijms20163920 . PMC   6719079 . PMID   31409014.
  8. ↑ Fernández-Agulló, A.; Pereira, E.; Freire, M.S.; Valentão, P.; Andrade, P.B.; González-Álvarez, J.; Pereira, J.A. (2013). "Influence of solvent on the antioxidant and antimicrobial properties of walnut (Juglans regia L.) green husk extracts". Ind. Crops Prod. 42: 126–132. doi:10.1016/j.indcrop.2012.05.021.
  9. ↑ Beiki, T.; Najafpour, G.D.; Hosseini, M. (2018). "Evaluation of antimicrobial and dyeing properties of walnut (Juglans regia L.) green husk extract for cosmetics". Color. Technol. 134: 71–81. doi: 10.1111/cote.12322 .
  10. ↑ Chen, G.; Pi, X.-M.; Yu, C.-Y. (2015). "A new naphthalenone isolated from the green walnut husks of Juglans mandshurica Maxim". Nat. Prod. Res. 29 (2): 174–179. doi:10.1080/14786419.2014.971789. PMID   25338229. S2CID   1757099.
  11. ↑ Wenzel, J.; Samaniego, C.S.; Wang, L.; Burrows, L.; Tucker, E.; Dwarshuis, N.; Ammerman, M.; Ammerman, Z.; Ammerman, A. (2017). "Antioxidant potential of Juglans nigra, black walnut, husks extracted using supercritical carbon dioxide with an ethanol modifier". Food Science & Nutrition. 5 (223–232): 223–232. doi:10.1002/fsn3.385. PMC   5332255 . PMID   28265357.
  12. ↑ Noshirvani, N.; Fasihi, H.; Moradipayam, A. (2015). "Study on the antioxidant effects of extract and powder of green walnut hulls on the oxidation of sunflower oil". Iran. J. Nutr. Sci. Food Technol. 10: 79–90.
  13. ↑ Wang, X.S.; Li, Z.Z.; Tao, S.R. (2009). "Removal of chromium (VI) from aqueous solution using walnut hull". J. Environ. Manag. 90 (2): 721–729. doi:10.1016/j.jenvman.2008.01.011. PMID   18343014.
  14. ↑ Alston, Diane G.; Murray, Marion; Barnhill, James (January 2015). "Walnut Husk Fly". extension.usu.edu. Utah State University. Retrieved 20 October 2023.
  15. ↑ Reza Mehrasbi, Mohammad; Farahmandkia, Zohreh; Taghibeigloo, Bahareh; Taromi, Azra (2009). "Adsorption of Lead and Cadmium from Aqueous Solution by Using Almond Shells". Water, Air, and Soil Pollution. 199 (1–4): 343–351. Bibcode:2009WASP..199..343M. doi:10.1007/s11270-008-9883-9. S2CID   96361261.
  16. ↑ Jahanban Isfahlan, A.; Mahmoodzadeh, A.; Hasanzadeh, A.; Heidari, R.; Jamei, R. (2010). "Antioxidant and antiradical activities of phenolic extracts from Iranian almond ( Prunus amygdalus L.) hulls and shells". Turk. J. Biol. 34: 165–173.
  17. ↑ "Coconut Shell Lump Charcoal". Supreme Carbon Indonesia. Archived from the original on December 29, 2012.
  18. ↑ "Coco Coir - 7 Things Every Gardener Should Know". DIY Gardening. Retrieved 20 October 2023.
  19. ↑ Tabil, Lope (July 6–9, 2003). "Conditioning and Dehulling of Pigeon Peas and Mung Beans". The Canadian Society for Engineering in Agricultural, Food and Biological Systems: 03–347.
  20. ↑ "e-Learning for agriculture and fisheries". e-extension.gov.ph. Retrieved 2024-08-28.
  21. ↑ Cote, Wilfred (2013-12-01). Biomass Utilization. Springer Science & Business Media. ISBN   9781475708332. Archived from the original on 2017-12-12.


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