Esters bananas

Backbone (protein), 1028 Backside displacement. reaction and.363-364 von Baeyer, Adolf, 113 Baeyer strain theory, 113-114 Bakelile, structure of, 1218 Banana, esters in, 808 Barton, Derek, H. R., 389 Basal metabolic rate, 1169 Basal metabolism. 1169-1170 Base, Bronsted-Lowry, 49 Lewis, 57, 59-60 organic, 56-57 strengths of, 50-52 Base pair (DNA), 1103-1105 electrostatic potential maps of. 

Fruity Tropical fruit, ethyl acetate, pineapple, banana, pear Stone fruit, apple cider, toffee apple, quince, dried pear, floral, fruity ester, banana ester,ethyl acetate, cooked apricot,pineapple... 

Gilliver PJ, Nursten HE (1976) The source of the acyl moiety in the biosynthesis of volatile banana esters. J Sci Food Agric 27 152-158... 

Isoamyl acetate is the common name of the substance most responsible for the characteris tic odor of bananas Wnte a structural formula for isoamyl acetate given the information that it IS an ester in which the carbonyl group bears a methyl substituent and there is a 3 methylbutyl group attached to one of the oxygens... 

Esters are among the most widespread of all naturally occurring compounds. Many simple esters are pleasant-smelling liquids that are responsible for the fragrant odors of fruits and flowers. For example, methyl butanoate is found in pineapple oil, and isopentyl acetate is a constituent of banana oil. The ester linkage is also present in animal fats and in many biologically important molecules. 

Ethanol and propanoic acid react to form the ester ethyl propanoate, which has the odour of bananas. 

Synonyms Acetic acid, amyl ester Acetic acid, pentyl ester AI3-02729 rt-Amyl acetate Amyl acetate Amyl acetic ester Amyl acetic ether /r-Amyl ethanoate Banana oil Birnenoel BRN 1744753 Caswell No. 049A Chlordantoin EPA pesticide chemical code 000169 Holiday pet repellant Holiday repellant dust NSC 7923 Pear oil Pentacetate Pentacetate 28 1-Pentanol acetate 1-Pentyl acetate /3-Pentyl acetate Pentyl acetic ester /3-Pentyl ethanoate Primary amyl acetate UN 1104. 

Synonyms Acetic acid, isopentyl ester Acetic acid, 3-methylbutyl ester AI3-00576 Banana oil BRN 1744750 CCRIS 6051 EINECS 204-662-3 FEMA No. 2055 Isoamyl ethanoate Isopentyl acetate Isopentyl alcohol acetate 3-Methyl-1-butanol acetate 3-Methylbutyl acetate 3-Methyl-1-butyl acetate 3-Methylbutyl ethanoate NSC 9260 Pear oil UN 1104. 

Here are some additional examples of esters as aromas or flavors propyl acetate is the aroma of pears pentyl acetate is the aroma of bananas octyl acetate is that for oranges. 

The short-tailed fmit bat, Carollia perspicillata, discriminates the odor of ripe from that of green bananas. Odor cocktails of banana odor components were distinguished from the whole odor of banana (Laska, 1990). The two most common esters of banana odor are isopentyl acetate and isobutyl acetate. Nearly all fruit odors contain ethyl acetate. Isopropyl acetate and 2-pentanone are characteristic of putrefying fruits. 

Synonyms Amyl acetate banana oil pear oil amylacetic ester 3-methyl butyl acetate 3-methyl-1-butanol acetate... 

Banana (Musa sapientum L.) is one of the most common tropical fruits, and one of Central America s most important crops. It is grown in all tropical regions and is one of the oldest known fruits [45]. From a consumer perspective, bananas are nutritious with a pleasant flavour and are widely consumed throughout the world [57]. Esters predominate in the volatile fraction of banana (Fig. 8.2). Acetates are present in high concentrations in the fruit and generally possess a low threshold. Isopentyl acetate and isobutyl acetate are known as the two most important impact compounds of banana aroma. Alcohols are the second most important group of volatiles in banana extracts. 3-Methyl-1-butanol, 2-pentanol, 2-methyl-1-propanol, hexanol, and linalool are the alcohols present in higher concentrations in the fresh fruit [45]. 

Fig. 8.2 Esters as character-impact compounds 4 isobutyl acetate in passion frml 5 isopentyl acetate in banana 6 ethyl butanoate in cupuacu 7 ethyl (32)-hexenoate and 8 ethyl-3-(methylthio)propanoate in pineapple...

Scheme 26.3 Biosynthesis of volatile esters catalysed by alcohol acyltransferases. SAAT strawberry alcohol acyltransferase, VAAT Pragaria vesca alcohol acyltransferase, ATFl, AFT2 Saccharomyces cerevisiae alcohol acetyltransferases, BanAAT banana alcohol acyltransferase...

Esters also constitute a group of important flavour compounds. They are the main aroma components found in fruits (apples, pears,. ..). For example, bananas contain 12-18 ppm acetates. The price of the pure flavour compounds, when isolated from fruit, can range between 10,000 and 100,000 US /kg In the past, research has been carried out by our group about the microbial production of fruity esters by the yeast Hansenula mrakii and the fungus Geotrichum penicillatum [10]. A fermentation was developed whereby fusel oil was continuously converted into a mixture of 3-methylbutyl acetate (isoamyl acetate) and 2-methylbutyl acetate, the character impact compounds of banana flavour. 

Esters, which contain the C 0 C functional group, have many uses in medicine, industry, and living systems. In medicine, a number of important pharmaceutical agents, including aspirin and the local anesthetic benzocaine, are esters. In industry, polyesters such as Dacron and Mylar are used to make synthetic fibers and films. In nature, many simple esters are responsible for the fragrant odors of fruits and flowers. For example, pentyl acetate is found in bananas, and octyl acetate is found in oranges. 

The odor of these bananas is due to pentyl acetate, a simple ester. 

Amyl Acetate or Amylacetic Ester(commonly known as Banana Oil),C5 Htl.COOCH mw 130.18- Several isomers are known of which n-amyl acetate and isoamyl acetate are the most important. They can be prepd by heating amyl alcohols with acetic acid in the presence of some sulfuric acid. Industrial methods of prepn are given in Ref 9,pp 102—3- Commercial products are usually mixts of n- and iso-amyl acetates. When amyl acetate is prepd from "fusel oil (a byproduct obtained in the raanuf of ethyl ale by fermentation), the chief component is isoamyl acetate... 

The IUPAC rules name esters as alkyl alkanoates. That is, the portion of the ester derived from the alcohol is named as an alkyl group. The portion of the ester that is derived from the carboxylic acid is named as the conjugate base of that acid. It is easy to distinguish these parts. The half derived from the carboxylic acid has the carbonyl group. Pentyl ethanoate, or pentyl acetate, is one ester used as artificial banana flavoring. Figure 11.51 shows three ester nomenclature examples. 

Chemical Name S -(ferf-butylthio)methyl O, O-diethyl phosphorodithioate />-[[( 1,1-dimethylethyl)Lhio] methyl 0,0-diethyl phosphorodithioate phosphorodithioic acid S-((/er/-butylthio)methyl) 0,0-diethyl ester Uses insecticide in soil to control insects and also used as nematocide to control nematodes in beet, maize, cotton, sorghum, onions, cabbage, and bananas. 

Place the test tubes in a warm water bath at 60°C for 15 min. Remove the test tubes from the water bath, cool, and add 2 mL of water to each. Note that there is a layer on top of the water in each test tube. With a Pasteur pipet, take a few drops from this top layer and place on a watch glass. Note the odor. Match the ester from each test tube with one of the following odors banana, peach, raspberry, nail polish remover, wintergreen. 

In general, acid chlorides and acid anhydrides are too reactive to occur naturally, and nitriles are rare in nature. Esters and amides, on the other hand, are very common. Many esters have pleasant odors, often sweet or fruity, and are responsible for the fragrant odors of fruits and flowers. They are components of many flavorings, both natural and artificial. For example, isopentyl acetate has a strong banana odor, and methyl bu-tanoate is used as an artificial rum flavoring. Typical fats are triesters formed from long-chain fatty acids and the triol glycerol. 

Some examples of naturally occurring esters and amides are shown here. Isoamyl acetate gives ripe bananas their characteristic odor, and geranyl acetate is found in the... 

Esters are among the most common acid derivatives. They are found in plant oils, where they give the fruity aromas we associate with ripeness. For example, the odor of ripe oil ITIITI3 ry OT thG bananas comes mostly from isoamyl acetate. Oil of wintergreen contains methyl sali- ChGlTI istfV Of Esters... 

Other, more volatile esters, have pleasant, fruity smells and flavours. These three are components of the flavours of bananas, rum, and apples ... 

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