Banana odor

Methyl Amyl Ketone. Methyl amyl ketone [110-43-0] (MAK) (2-heptanone) is a colorless Hquid with a faint fmity (banana) odor. It is found in oil of cloves and cinnamon-bark oil, and is manufactured by the condensation of acetone and butyraldehyde (158). Other preparations are known (159-162). 

Mammalian odor reception is modulated by relative humidity. For instance, neotropical bats Carollia perspicillata and Phyllostomus discolor) are less able to approach an experimental banana odor correctly if the humidity is lowered from the normal 75% to under 60%. The sensoiy impairment results from drying out of the nasal mucosa in low humidity (Laska etal., 1986). 

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. 

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. 

These alcohols and their esters have intense odors that play a role in wine aromas. The main higher fermentation alcohols, components of Fusel oils, are isobutyl (methyl-2-propanol-l) and amyl alcohols (a mixture of methyl-2-butanol-l and methyl-3-butanol-l). At low concentrations (less than 300 mg/1), they contribute to a wine s aromatic complexity. At higher levels, their penetrating odors mask the wine s aromatic finesse. Acetic esters of these alcohols, especially isoamyl acetate, have a banana odor that may play a positive role in the aroma of some young red wines (primeur or nouveau). 

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... 

Methylbutyl acetate (contributes to characteristic odor of bananas)... 

Observable Characteristics - Physical State (as normally shipped) Liquid Color Colorless to yellow Odor. Pleasant banana-like mild characteristic banana- or pear- like odor ... 

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. 

Colorless liquid with a sweet, banana-like odor. A detection odor threshold concentration of 275 pg/m (52 ppbv) was reported by Punter (1983). Cometto-Muniz and Cain (1991) reported an average nasal pungency threshold concentration of 1,650 ppmv. 

Clear, colorless liquid with a strong fruity odor resembling bananas. Sweetish taste as low concentrations (<30 gg/L). Experimentally determined detection and recognition odor threshold concentrations were 30 gg/m (6.3 ppbv) and 18 gg/m (38 ppbv), respectively (Heilman and Small, 1974). Cometto-Muhiz et al. (2000) reported nasal pungency threshold concentrations ranged from approximately 550 to 3,500 ppm. 

Colorless liquid with a banana-like odor. Can be detected at a concentration of 140 pg/kg (Buttery et al, 1969a). Cometto-Muniz et al. (2000) reported nasal pungency threshold concentrations ranging from approximately 195 to 935 ppm. An odor threshold concentration of 6.8 ppbv was reported by Nagata and Takeuchi (1990). 

Clear, colorless liquid with a banana or pear-like odor. Odor threshold concentration is 7 ppm (quoted, Keith and Walters, 1992). A detection odor threshold concentration of 18 pg/m (3.4 ppbv) was determined by Katz and Talbert (1930). 

Preschool children are reputed to differ from adults in their odor preferences. For instance children aged 3-4 years were as likely to like the odor of amyl acetate (banana) as synthetic sweat or feces odors. By 6 years of age, their preferences resembled adults, liking banana, and disliking sweaty and fecal odors (Stein et al., 1958). At 4-5 years of age, a shift occurs from positive or neutral to negative characterization of odors of sweat, feces, asa foetida, or butyric acid. However, it is increasingly becoming clear that responses by very young children... 

Isoamyl acetate was not mutagenic in a number of assays. It has a banana- or pearlike odor detectable at 7 ppm. ... 

Odor — shall have characteristic "banana oil odor and shall leave no residual odor when tested accdg to FedTestMethodSrd No 141a, Method 4401, Sept I, 1965 Procedure Note the odor immediately upon opening the container. In addition, dip a strip of heavy filter paper (Whatman No 2 or equal) into container with EtAcet and hang the test strip on a suitable support. Place it in... 

Practical experience abetted by statistical surveys reveals a wide diversity of taste and odor preferences among peoples worldwide. For example, in studying preferences for flavored yogurt, strawberry is the clear winner in a majority of countries surveyed. Exceptions were a preference for cheny (Germany), citrus (Japan), coffee (Swiizerland). and blueberry (Austria). The least preferred flavors were orange, tropical, peach, and banana flavors. 

Acetic acid (CH3C02H) reacts with isopentyl alcohol (C5H12O) to yield isopentyl acetate (C7H14O2), a fragrant substance with the odor of bananas. If the yield from the reaction of acetic acid with isopentyl alcohol is 45%, how many grams of isopentyl acetate are formed from 3.58 g of acetic acid and 4.75 g of isopentyl alcohol The reaction is ... 

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. 

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