Application of Solid-Phase Microextraction for the Analysis of Aroma Compounds from Pineapple Fruit

Abstract

An analytical method of solid-phase microextraction (SPME) was developed for pineapple aroma volatile compounds. Different sample preparation procedures involving SPME fibres, including the addition of sodium chloride, extraction time, and temperature, were evaluated to optimise the method. For the optimised method, 6.5 g of ground pineapple flesh was placed in a 20 mL headspace vial with 1 g of sodium chloride; a 65 μm polydimethylsiloxane/divinylbenzene fibre was used for extraction at 50°C for 40 min with continuous stirring. The method was validated by determining its repeatability and recovery. The relative standard deviations for the pineapple aroma compounds were 5.48-11.02%. The average method recovery was 99.13%. The results demonstrate that this SPME procedure is suitable as a simple, rapid, and solvent-free extraction technique for the analysis of pineapple aroma volatile compounds. Using this method, 15 volatile compounds were identified, and the amount was 1019.78 μg.kg−1 in pineapple cv. Shenwan, including seven esters, one terpene, two aldehydes, one ketone, two lactones, one alcohol, and one hydrocarbon. A tentative study to estimate the contribution of the identified compounds to the aroma of the pineapple variety based of their odour activity values indicated four compounds that were characteristic aroma compounds, including methyl hexanoate, δ-octalactone, decanal, and geranyl acetone.