Volatile aroma chemical constituents of fruit pulp of some Kenyan varieties of mango (Mangifera indica L.)

Abstract

Volatiles are key constituents of mango fruit aroma and vital in defining fruit quality besides influencing consumer preferences. In this paper, volatiles of eight Kenyan mango varieties: Ngowe, Apple, Keitt, Boribo, Tommy Atkins, Van Dyke, Sabre and Kent were collected on porapak Q adsorbent filters (mesh 40-80μm) using air entrainment kit and analyzed by Gas Chromatography (GC) and GC coupled to a Mass Spectrometer. Fifty-eight compounds, representing monoterpenes (66.1%), esters (19.7%), sesquiterpenes (4.8%), non-terpenoid hydrocarbons (3.1%), and oxygenated compounds (ethers, alcohols, acids and carbonyls) (6.3%), were identified. Some quantitative differences were observed in the distribution of monoterpenes in the mangoes with three distinguishable aroma groups being noted. The first was rich in -pinene and present in all the eight varieties, with significant amounts in Ngowe (10.93%), Apple (34.92%) and Van Dyke (7.42%). The second group, rich in myrcene, included Ngowe (22.74), Apple (24.36%) and Boribo (57.04%). The third was rich in δ-3-carene and comprised Keitt (25.76%), Tommy Atkins (27.07%), Van Dyke (25.6%), Sabre (30.31%) and Kent (35.0%). (E)- Caryophyllene was identified in all varieties while ethyl butanoate was present in all except Sabre and Kent. Ethyl butanoate, -pinene, myrcene, and δ-3-carene have also been found as dominant aroma volatiles in different mango varieties globally. Moreover, δ-3-carene, which is a major compound in Keitt, Tommy Atkins and Kent in this study, also dominates the same varieties in other parts of the world. The qualitative and quantitative