How Is Banana Aroma Obtained?

Banana aroma is chemically isoamyl acetate.

Isoamyl acetate is an ester. It is a carboxylic acid derivative. Esters are the products of an equilibrium reaction between an alcohol and a carboxylic acid.

The general reaction for obtaining esters is as follows.

Isoamyl alcohol (1 mol) and acetic acid (2 mol) are placed in a 500 ml round-bottom flask. 25 ml of concentrated H2SO4 is added while swirling. After adding a boiling chip, a reflux condenser is attached and the mixture is gently boiled for 2 hours. The mixture is transferred to a 250 ml distillation flask and distilled without exceeding 100 °C.

The crude product is transferred to a large beaker. It is treated with a 20% Na2CO3 solution to remove acid residues. It is then transferred to a separatory funnel. The crude ester is washed with a solution of 20 g CaCl2 in 20 ml water to remove the alcohol.

It is dried over anhydrous Na2SO4 for at least 45 minutes, filtered and distilled again.

Benzyl acetate: peach aroma

Methyl n-butyrate: apple aroma

n-Propyl acetate: pear aroma

Isoamyl acetate: banana aroma

Methyl cinnamate: strawberry aroma

Source:

https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Book%3A_Organic_Chemistry_Lab_Techniques_(Nichols)/04%3A_Extraction/4.06%3A_Reaction_Work-Ups

Erdik E., Obalı M., Yüksekışık N., Öktemer A., Pekel T., "Denel Organik Kimya" (Experimental Organic Chemistry). Gazi Kitabevi, Ankara, 2007, 4th ed. (expanded), pp. 680-714

Tüzün C., "Organik Kimya" (Organic Chemistry). Palme Yayıncılık, Ankara, 1996, revised 7th ed., pp. 210-218