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.

Potential of Industrial Pineapple (Ananas comosus (L.) Merrill) By-Products as Aromatic and Antioxidant Sources

“…The core pineapple sample was selected for the optimization of HS-SPME procedure. The variables were evaluated in a selected ranges on the basis of results obtained in previous analysis and the previous references found [ 7 , 8 ].…”

“…The core pineapple sample was selected for the optimization of HS-SPME procedure. The variables were evaluated in a selected ranges on the basis of results obtained in previous analysis and the previous references found [7,8]. The relationship between the response (Y) and the parameters of independent variables was used to monitor the optimization process.…”

“…Regarding the volatile profile, previous works reported esters as main components, contributing Antioxidants 2021, 10, 1767 2 of 15 50-80% of the total volatile compounds identified and being related to the quality of the flavor of different pineapple parts [6]. Apart from esters, other volatile compounds present in pineapple are terpenes (2-30%), alcohols (16%), acids (7-14%), aldehydes (10-13%), lactones (2-13%), phenolic compounds (6-12%), and ketones (7-10%) [7,8].…”

“…To characterize the volatiles, present in pineapple by-products, Headspace Solid Phase Microextraction (SPME) coupled with Gas Chromatography–Mass Spectrometry (GC-MS) is a relatively inexpensive, easy-to-use analytical technique that is widely applied to volatile compound profile analysis. This technique has also been used to characterize the aroma of pineapples combining extraction and preconcentration in a single step [ 6 , 7 , 8 ]. Some parameters, such as the extraction temperature and time, salinity of the medium, pH, amount of solvent, and the sample amount and/or volume, among others, directly influence the extraction process using HS-SPME [ 14 ].…”

“…In this sense, previous studies have described the effect of the addition of a saline solution on the efficiency of the extraction of volatile aromatic compounds in pineapple at different concentration levels [ 15 ]. Regarding the extraction temperature in pineapple samples, the reported values of this parameter in studies carried out are between 25–40 °C, while the most suitable extraction time is around 40 and 60 min, depending on the study [ 6 , 7 , 8 ]. However, optimal operating conditions related to the extraction process of volatile compounds can be obtained using more complex experimental designs, such as the Doehlert matrix (DM), the central compound design (CCD), and three-level designs, such as the Box–Behnken (BBD) design.…”