Fruit esters

Uses. Plastics, lacquers, cellulose esters, fruit essences, perfumes, and chemical intermediates additive to unleaded gasoline... 

HCOOCHjCHj. Colourless liquid with the odour of peach-kernels b.p. 54 C, Prepared by boiling ethanol and methanoic acid in the presence of a little sulphuric acid the product is diluted with water and the insoluble ester separated and distilled. Used as a fumigant and larvicide for dried fruits, tobacco and foodstuffs. It is also used in the synthesis of aldehydes. 

The above example serves to iUustrate the basis of the procedure employed for the characterisation of aUphatic esters, viz., hydrolysis to, and identification of, the parent acids and alcohols. Most esters are liquids a notable exception is dimethyl oxalate, m.p. 54°. Many have pleasant, often fruit-hke, odours. Many dry esters react with sodium, but less readily than do alcohols hydrogen is evolved particularly on warming, and a sohd sodio derivative may separate on coohng (e.j/., ethyl acetate yields ethyl sodioacetoacetate ethyl adipate gives ethyl sodio cj/cZopentanone carboxylate). 

Many esters occur naturally Those of low molecular weight are fairly volatile and many have pleasing odors Esters often form a significant fraction of the fragrant oil of fruits and flowers The aroma of oranges for example contains 30 different esters along with 10 carboxylic acids 34 alcohols 34 aldehydes and ketones and 36 hydrocarbons... 

Linalol is a tertiary alcohol of the formula Cj HjgO, which, with its acetic ester (and traces of other esters) forms the basis of the perfume,of bergamot and lavender oils. By dehydration linalol is converted into terpenes of which the principal are limonene and dipentene, and by esterification into its acetic ester. The examination of the essential oil at different periods of the development of the bergamot fruit has led Charabot and Laloue to the following conclusions. As the fruit matures the essential oil undergoes the following modifications —... 

The practical conclusion to he drawn from this is as follows Oil of bergamot having a value which increases accoi ding to the richness in ester, it will be profitable to gather the harvest at the period at which the fruit is fully ripe. 

Hexyl Butyrate.—This ester is also a powerful fruit oil, and boils at 205°. 

Cinnamyl Propionate.—The propionic acid ester has a distinct grapelike odour, and is very useful for fruit and flower blends. It has the constitution. CH CH. CH,OOC. CH,. CH,. 

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. 

Esters are important substances. The esters of the low molecular weight acids and alcohols have fragrant, fruit-like odors and are used in perfumes and artificial flavorings. Esters are useful solvents this is the reason they are commonly found in model airplane dope and fingernail polish remover. 

A liquid detergent for dishes, vegetables, and fruit comprises the sodium salt of a-sulfo coconut acid ethyl ester (20%), an alkylamine oxide (5%), citric acid (0.5%), ethanol (50%), and water [78]. 

Many esters have fragrant odors and contribute to the flavors of fruits. For example, benzyl acetate, CH3COOCH2C6Hs, is an active component of oil of jasmine. Other naturally occurring esters include fats and oils. For example, the animal fat tristearin (12), which is a component of beef fat, is an ester formed from glycerol and stearic acid. 

BREITHAUPT D E and BAMEDIA (2001) Carotenoid esters in vegetables and fruits A screening with emphasis on P-cryptoxanthin esters. JAgric Food Chem 49(4) 2064-70. 

Pfister, S. et al.. Isolation and structure elucidation of carotenoid-glycosyl esters in gardenia fruits Gardenia jasminoides Ellis) and saffron (Crocus sativus Linne), J. Agric. Food Chem., 44, 2612, 1996. 

Carmona, M. et al., Crocetin esters, picrocrocin and its related compounds present in Crocus sativus stigmas and Gardenia jasminoides fruits. Tentative identification of seven new compounds by LC-ESl-MS, J. Agric. Food Chem., 54, 973, 2006. 

Alkaline hydrolysis (saponification) has been used to remove contaminating lipids from fat-rich samples (e.g., pahn oil) and hydrolyze chlorophyll (e.g., green vegetables) and carotenoid esters (e.g., fruits). Xanthophylls, both free and with different degrees of esterification with a mixture of different fatty acids, are typically found in fruits, and saponification allows easier chromatographic separation, identification, and quantification. For this reason, most methods for quantitative carotenoid analysis include a saponification step. 

Inbaraj, B. S., H. Lu et al. (2008). Determination of carotenoids and their esters in fruits of Lycium barbarum Linnaeus by HPLC-DAD-APCI-MS. J. Pharm. Biomed. Anal. 47(4-5) 812-818. 

Esters have a pleasant, fruity odor. Indeed, the odors of many fruits and oils are due to esters. Esters... 

Naesens, L., Clercq, E. de, Van den Mooter, G., Kinget, R., Augustijns, P., Inhibition of intestinal metabolism of the antiviral ester prodrug bis(POC)-PMPA by nature-identical fruit extracts as a strategy to enhance its oral absorption an in vitro study, Pharm. Res. 1999, 16, 1035-1040. 

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