Ripening 361993 225498476 2008-07-14T00:37:56Z 70.16.52.138 {{Cleanup|date=June 2008}} [[Image:MeyerLemon.jpg|thumb|200px|This [[lemon]] will turn yellow as it ripens.]] [[Image:Lemon-edit1.jpg|thumb|200px|Ripe lemons.]] '''Ripening''' is a process in [[fruit]]s that causes them to become more [[edible]]. In general, a fruit becomes [[sweetness|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 hormone]]s. 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 [[enzyme]]s in fruit and [[fresh-cut]] products, which include: * [[Amylase]], which hydrolyzes [[starch]] to produce simple [[sugar]]s, 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 [[seed]]s in a multiseeded fruit are formed (by [[fertilization]] of the [[ovule]]s), 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, [[banana]]s 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 [[persimmon| Hachiya persimmons]], are eaten only after [[bletting]], the [[Fermentation (food)|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 [[Category:Fruit]] [[Category:Horticulture]] [[it:Maturazione frutti]] [[he:הבשלה]] [[simple:Ripening]] [[uk:Визрівання]]