Ripening


Ripening

Ripening is a process in fruits that causes them to become more edible. In general, a fruit becomes sweeter, less green, and softer as it ripens. However the acidity as well as sweetness rises during ripening, but the fruit still tastes sweeter regardless. The reason for this is the Brix-Acid Ratio.

The life stages of a plant are influenced by plant hormones. An organic compound involved with ripening is ethylene, a gas created by plants from the amino acid methionine. Ethylene increases the intracellular levels of certain enzymes in fruit and fresh-cut products, which include:

* Amylase, which hydrolyzes starch to produce simple sugars, and
* Pectinase, which hydrolyzes pectin, a substance that keeps fruit hard.

Other enzymes break down the green pigment chlorophyll, which is replaced by blue, yellow, or red pigments.

Hormone levels in fruit are often connected to pollination. If too few seeds in a multiseeded fruit are formed (by fertilization of the ovules), the flesh of the fruit may not develop in some areas, and as a consequence ripening will be retarded or prevented. Fruit growers increasingly monitor seed ratios in developing and/or mature fruit and adjust pollination management accordingly.

Many fruits are picked prior to full ripening because ripened fruits do not ship well. For example, bananas are picked when green and artificially ripened after shipment by being gassed with ethylene. A similar method used in parts of Asia was to cover a bed of slightly green-harvested mango and a few small open containers of clumps of calcium carbide with a plastic covering. The moisture in the air reacted with the calcium carbide to release the gas acetylene, which apparently has the same effect as ethylene.

Some fruits, such as Hachiya persimmons, are eaten only after bletting, the fermenting process of decay after severe ripening.

SmartFresh is a technology useful to maintain fresh-picked quality of whole fruits and vegetables. 1-Methylcyclopropene (1-MCP 0.14%) works with the ripening process to dramatically slow down ethylene production and prevent over-ripening and problems associated with aging.

Iodine (I) can be used to check if the fruit is ripening or rotting by showing whether starch in the fruit has turned into sugar. For example, in an apple that has rotted (not bruised, just rotted) a drop of iodine on a slightly rotten part (not skin) will turn a dark blue or black color if there is starch there. If it stays yellow, then most of the starch did turn into sugar.

Artificial ripening

Calcium carbide is used for ripening the fruit artificially in some countries. Calcium carbide contains traces of arsenic and phosphorus and thus use of this chemical is illegal in most of the countries. Calcium carbide once dissolved in water produces acetylene which is the essential gas for ripening process. Acetylene is believed to affect the nervous system by reducing oxygen supply to brain.

References

* http://plantphys.info/plants_human/fruitgrowripe.html
* http://www.actahort.org/books/398/398_17.htm
* http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=549760


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • ripening — index growth (evolution) Burton s Legal Thesaurus. William C. Burton. 2006 …   Law dictionary

  • Ripening — Ripen Rip en, v. i. [imp. & p. p. {Ripened};p. pr. & vb. n. {Ripening}.] 1. To grow ripe; to become mature, as grain, fruit, flowers, and the like; as, grapes ripen in the sun. [1913 Webster] 2. To approach or come to perfection. [1913 Webster] …   The Collaborative International Dictionary of English

  • ripening — nokimas statusas T sritis augalininkystė apibrėžtis Paskutinis augalo vaisiaus brendimo tarpsnis. atitikmenys: angl. ripening rus. созревание …   Žemės ūkio augalų selekcijos ir sėklininkystės terminų žodynas

  • ripening — 1) the process of becoming a ripe fish 2) maturing of small fatty fishes, e.g. anchovies and herring, in salt, sugar and spices in barrels over several months. Proteins and lipids are degraded by enzymes from the pyloric caeca of the fish and a… …   Dictionary of ichthyology

  • ripening — noun The process of becoming ripe …   Wiktionary

  • ripening — Denoting progressive oxidation of dye solutions, as in the r. of hematoxylin solutions to hematein or of methylene blue to azure dyes …   Medical dictionary

  • ripening — The process of maturing in plants resulting in seeds that are fully developed and can be used to grow new plants …   Combined glossary of agriculture

  • ripening — n. maturation, process of becoming fully grown or developed; process of making mature, process of bringing to a state of full development or growth rip·en || raɪpÉ™n v. mature, become fully grown or developed; cause to mature, bring to a state… …   English contemporary dictionary

  • ripening — noun 1. coming to full development; becoming mature (Freq. 1) • Syn: ↑maturation, ↑maturement • Derivationally related forms: ↑mature (for: ↑maturement), ↑ripen, ↑ …   Useful english dictionary

  • ripening process — process of maturation, process of development and growth …   English contemporary dictionary


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.