why ethylene can accelerate ripening of fruit?

Ethylene (IUPAC name: ethene) is an organic compound, a hydrocarbon with the formula C₂H₄ or H₂C=CH₂. It is a colorless flammable gas with a faint "sweet and musky" odor when pure.^] It is the simplest alkene (a hydrocarbon with carbon-carbon double bonds), and the simplest unsaturated hydrocarbon after acetylene (C₂H₂).

Ethylene is a plant hormone first in the form of gas. If the fruit is ripe oranges combined with bananas, ripe bananas are faster because oranges emit ethylene gas. The discovery of this hormone in plants first described by R. Gane in 1934.

Ethylene is a plant and cause more rapid maturation in many fruits, including bananas. Ethylene formation requires O2 and is inhibited by CO2. All parts of the plant can produce ethylene gas angiosperms. Formation mainly occurs in roots, shoot apical meristem, mode, fall flowers and ripe fruit.

In fruit ripening, ethylene working to solve the chlorophyll in young fruit, so the fruit has only xantofil and carotene. Thus, the color becomes orange or red fruit.
In other applications, ethylene is used as an anesthetic (anesthetic).

Calcium Carbide is NOT safe for ripening. Calcium Carbide is used in some countries as source of acetylene gas, which is an artificial ripening agent. However, acetylene is not nearly as effective for ripening as is ethylene, and acetylene is not a natural plant hormone like ethylene. Also, calcium carbide may contain traces of arsenic and phosphorus, both highly toxic to humans, and the use of this chemical for ripening is illegal in most countries.

ethylene

Ethylene (C2H4)

ETHYLENE FACTS

Ethylene is a natural plant hormone.
It affects the growth, development, ripening, and senescence (aging) of all plants. It is normally produced in small quantities by most fruits and vegetables. Many fruits produce larger quantities of ethylene and respond with uniform ripening when exposed to an external source of ethylene.

Ethylene is Generally Recognized as Safe (GRAS)
by the United States Food and Drug Administration (FDA). Given the numerous amounts of food substances, the FDA does not categorize every one. Salt, pepper and vinegar are examples. These, along with ethylene, all are within the category of food substances that, when used for the purposes indicated, in accordance with good manufacturing practice, are regarded by the FDA as generally recognized as safe (GRAS) for such uses.

Calcium Carbide is NOT safe for ripening. Calcium Carbide is used in some countries as source of acetylene gas, which is an artificial ripening agent. However, acetylene is not nearly as effective for ripening as is ethylene, and acetylene is not a natural plant hormone like ethylene. Also, calcium carbide may contain traces of arsenic and phosphorus, both highly toxic to humans, and the use of this chemical for ripening is illegal in most countries.

Ethylene has been found not harmful or toxic to humans in the concentrations found in ripening rooms.
In fact, ethylene was used medically as a anesthetic in concentrations significantly greater than that found in a ripening room. However, ethylene is often targeted as the reason for difficulty in breathing in ripening rooms; what can affect some people is usually either:
a) Carbon Dioxide (CO₂,) levels: CO₂, is produced by the ripening fruit in the room and levels increase over time, or
b) Oxygen levels: The oxygen in the room when loaded is taken in by the ripening fruit. This sometimes will make breathing in a ripening room difficult. The increased CO₂, and decreased oxygen levels are the main reasons for venting the ripening room.

Ethylene action slows at lower temperatures.
At their minimum temperature levels, fruit is basically inactive and does not respond well to externally supplied ethylene.

Ethylene will penetrate most substances.
In fact, it will permeate through produce cardboard shipping boxes, wood and even concrete walls.

Ethylene is harmful to many fruits, vegetables, and floral items.
While ethylene is invaluable due to its ability to initiate the ripening process in several fruits, it can also be very harmful to many fruits, vegetables, flowers, and plants by accelerating the aging process and decreasing the product quality and shelf life. The degree of damage depends upon the concentration of ethylene, length of exposure time, and product temperature. One of the following methods should be used to ensure that ethylene-sensitive produce is not exposed:

Ethylene producing items (such as apples, avocados, bananas, melons, peaches, pears, and tomatoes) should be stored separately from ethylene-sensitive ones (broccoli, cabbage, cauliflower, leafy greens, lettuce, etc.). Also, ethylene is emitted by engines. Propane, diesel, and gasoline powered engines all produce ethylene in amounts large enough to cause damage to the ethylene-sensitive produce items mentioned;

1. Ventilate the storage area, preferably to the outside of the warehouse, on a continuous or regular basis to purge the air of any ethylene;
2. Remove ethylene with ethylene absorbing filters. These have been proven in reducing and maintaining low ethylene levels. If ethylene damage is suspected, a quick and easy way to detect ethylene levels is with hand held sensor tubes. This will indicate if the above steps should be followed.

Ethylene is explosive at high concentrations.
At 27,000 ppm, just a spark can ignite ethylene and cause a deadly explosion. However, when using our products as directed, reaching the explosive level is not possible. The explosive level is about 200 times greater than the level necessary to initiate ripening. Always use our generators in ripening rooms that is are 1500 ft³ or larger (43 m³).

Ethylene is used to 'degreen' citrus.
This is a natural process that triggers pigment changes: the loss of green peel color by removing the chlorophyll, which allows the orange or yellow to fully cover the entire peel. No loss of flavor is caused; this is merely a continuation of the natural plant process.

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ETHYLENE FAQ'S

The following are common questions about the use of ethylene gas in the ripening process. The material is reprinted from a fact sheet that has been available to the industry for many years.

What is the effect of ethylene on fruit ripening?
Ethylene can promote ripening in tomatoes, bananas, citrus, pineapples, dates, persimmons, pears, apples, melons, mangos, avocados, papayas and jujubes - a clear indication that the action of ethylene is general and widespread amongst a number of fruits. It is clear that ethylene is a ripening hormone - a chemical substance produced by fruits with the specific biological phenomenon of accelerating the normal process of fruit maturation and senescence.

PETROLEUM

Petroleum ( Latin petrus - rock and oleum - oil), also dubbed as the black gold, is a thick liquid, dark brown or greenish flammable, which is in the upper layers of the few areas in the earth's crust . Petroleum is composed of a complex mixture of different hydrocarbons, the majority of the alkane series, but vary in appearance, composition, and purity. Petroleum is a mixture of different types of hydrocarbons.

The composition of the crude oil (petroleum) is a complex mixture, consisting primarily of hydrocarbons, together with a small number of components containing sulfur, oxygen and nitrogen and very little metal-containing components.

The structure of the hydrocarbons found in crude oil:

Alkanes. This fraction is the largest in the crude oil.

Cycloalkanes (napten) cycloalkanes CnH2n anyone has a ring of 5 (five) the cyclopentane ring or 6 (six) is cyclohexane.

Aromatics Aromatics CnH2n -6 has a ring of 6 (six).

only present in small amounts, but it is necessary in gasoline because:
- Has anti-knock high prices
- Good storage stability
- And other uses as fuels (fuels).

The proportion of the three types of hydrocarbons depends on the source of petroleum. In general, an alkane hydrocarbon most but sometimes (referred to as crude napthenic) containing cycloalkanes as the largest component, while the aromatic component is always the least.

Refinery / distillation (refining) is the process of changing crude oil into products that can be sold (marketeble product) through a combination of physical and chemical processes. Products resulting from the refining / refining, among others:
1. Light destilates is the component with the smallest molecular weight. Here are a few pieces:

• Gasoline

Gasoline (United States) or motor spirit (UK) or gasoline (Indonesia) has the lowest boiling point and is a key product in the distillation is used as a propellant motors (45% of the crude oil processed to produce gasoline).

• Naphta
  Naphta is a material that has a boiling point between gasoline and kerosene. Some naphta used as: - Solvent rubber - starting materials ethylene - the military used as a jet fuel known as JP-4. - Solvent dry cleaning (washing)

• kerosine
  Kerosene has the highest boiling point and is usually used as:
- Kerosene
- Fuel for water jet plane

Intermediate destilates a gas oil or diesel fuel use as a transportation fuel heavy trucks, trains, small commercial boats, farm equipment and others.

Heavy destilates is a high molecular weight component. This fraction is usually converted into lubricating oil (lubricant oils), oil with high specific gravity of the fuel, candles and cracking stock.

Residues including asphalt, residual fuel oil and petrolatum. Residues that do not have a large percentage.

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organic chemistry

Organic chemistry is that branch of chemistry that deals with the structure, properties, and reactions of compounds that contain carbon. It is a highly creative science. Chemists in general and organic chemists in particular can create new molecules never before proposed which, if carefully designed, may have important properties for the betterment of the human experience. In terms of Ph.D. population, organic chemistry is the largest chemistry discipline, in both total numbers, annual Ph.D. graduates, and in annual production.

Beyond our bodies' DNA, peptides, proteins, and enzymes, organic compounds are all around us. They are central to the economic growth of the U.S., in industries such as the rubber, plastics, fuel, pharmaceutical, cosmetics, detergent, coatings, dyestuffs, and agrichemicals industries. The very foundations of biochemistry, biotechnology, and medicine are built on organic compounds and their role in life processes. Most all of the modern, high tech materials are composed, at least in part, of organic compounds. Clearly, organic chemistry is critically important to our high standard of living.