Aroma compounds solid-phase microextraction

Solid phase microextraction (SPME) is an ideal approach to monitor volatile flavor components. This approach has been used to identify the volatile compounds in the headspace of fresh fruit during maturation [92], Using SPME fibers and GC/MS, the key flavor components are hexanal, 2-isobutyl-3-methoxypyrazine, 2,3-butanedione, 3-carene, trans-2-hexenal, and linalool (Fig. 8.1). In this study, the principal aroma compounds whose abundance varied during fruit development were specifically identified. 

Mazidaa MM, SaUehb MM, Osman H (2005) Analysis of volatile aroma compounds of fresh chilli (Capsicum annuum) during stages of maturity using solid phase microextraction (SPME). J Food Comp Anal 18 427 37... 

Fig. 18.1 Systems used to absorb aroma compounds from samples for analytical purposes, a Traps loaded with various adsorbents [4]. b Solid-phase extraction (disk in a holder assembly) [5]. c Solid-phase microextraction (coated needle inserted in sample) [5]. d Twister (1 -cm length) [4]. (Courtesy of GERSTEL GmbH and Co. KG)...

Jirovetz, L., Buchbauer, G., Ngassoum, M.B. and Ceissler, M. (2002) Aroma compound analysis of Piper nigrum and Piper guineense essential oils from Cameroon using solid phase microextraction gas chromatography, solid phase microextraction gas chromatography mass spectrometry and olfactometry. 

Aroma compounds from vanilla beans have been extracted using several extraction procedures, using alcohols and organic solvents (Galletto and Hoffman, 1978 Dignum et al., 2002), direct thermal desorption (Hartman et al., 1992 Adedeji et al., 1993) and solid-phase microextraction (SPME) (Sostaric etal., 2000), followed by identification of the compounds by gas chromatography-mass spectrometry (GC-MS). 

Whiton, R.S., Zoecklein, B.W. (2000). Optimization of headspace solid-phase microextraction for analysis of wine aroma compounds. Am. J. Enol. Vitic., 51, 379-382. 

Recently, rotundone was identified as a pepper aroma impact compound in Shiraz grapes (Siebert et al.,2008). Identification was achieved by performing GC-MS analysis of grape juice after purification by solid-phase extraction (SPE) using a styrene-divinylbenzene 500-mg cartridge and elution with n-pentane/ethyl acetate 9 1, followed by solid-phase microextraction (SPME) using a 65-pm polydimethylsilox-ane-divinylbenzene (PDMS/DVB) fiber immersed in the sample for 60 min at 35 °C. J5-Rotundone was used as an internal standard. The structure of the compound is reported in Fig. 4.5. 

Solid-phase microextraction (SPME) of wine was developed by both headspace (HS) (Vas et al., 1998) and liquid-phase sampling (De la Calle et al., 1996). Exhaustive overviews on materials used for the extraction-concentration of aroma compounds in wines were published from Ferreira et al. (1996), Cabredo-Pinillos et al. (2004), and Nongonierma et al. (2006). 

Ferreira, A.C.S. and de Pinho, PG. (2003). Analytical method for determination of some aroma compounds on white wines by solid phase microextraction and gas chromatography, 1 Food Sci., 68(9), 2817-2820. 

Quantification of aroma-impact components by isotope dilution assays (IDA) was introduced in food flavor research by Schieberle and Grosch (1987), when trying to take into account losses of analytes due to isolation procedures. The labeled compounds have to be synthesized, the suitable fragments have to be chosen, and calibration has to be effected. A quantitative determination of ppb levels of 3-damascenone (Section 5,D.38) in foods, particularly in roasted coffee (powder and brew), was developed by Sen et al. (1991a). Semmelroch et al. (1995) quantified the potent odorants in roasted coffee by IDA. Hawthorne et al. (1992) directly determined caffeine concentration in coffee beverages with reproducibility of about 5 % using solid-phase microextraction combined with IDA. Blank et al. (1999) applied this combined method to potent coffee odorants and found it to be a rapid and accurate quantification method. They also concluded that the efficiency of IDA could be improved by optimizing the MS conditions. 

Analytical characterization of the aroma of Tinta Negra Mole red wine Identification of the main odorants compounds. Analytica Chimica Acta 563,154-164 Pizarro, C. Perez-del-Notario, N. Gonzalez-Saiz, J.M. (2007). Optimisation of a headspace solid-phase microextraction with on-fiber derivatisation method for the direct determination of haloanisoles and halophenols in wine. Journal of Chromatography A 1143,26-35... 

Solid Phase Microextraction (SPME) has become one of the preferred techniques in aroma analysis, offering solvent fi ee, rapid sampling with low cost and easy preparation. Also, it is sensitive, selective and compatible with low detection limits [18]. Placed in the sample headspace, SPME is a non-destructive and non-invasive method to evaluate volatile and semi-volatile compounds. In this sense, the extraction of volatile compounds released from a great number of foods has been carried out by using HS-SPME technique [29, 33],... 

Ho, C. W. Wan Aida, W. M Maskat, M. Y. Osman, H. Optimization of headspace solid phase microextraction (HS-SPME) for gas chromatography mass spectrometry (GC-MS) analysis of aroma compound in palm sugar (Arenga piimata, . Journal of Food Composition and AtMlysis,29, 19(8), 822-830. 

A comprehensive overview of the techniques most commonly used for instrumental analysis of flavor compounds in food has been recently reported [3]. Several methods used for sample treatment are described, as well as the following techniques for extraction prior to GC analysis solvent extraction and distillation techniques, headspace methods, and solid-phase microextraction. The use of GC-olfactometry and of ion-trap MS in food aroma analysis is also described. 

Table 3 Volatile Compounds Present in the Aroma Extracts of Boiled Pork, Using Solid-Phase Microextraction with Two Different Stationary Phases, Separately and Combined...

JS Elmore, DS Mottram, E Hierro. Two-fibre solid-phase microextraction combined with gas chromatography-mass spectrometry for the analysis of volatile aroma compounds in cooked pork. J Chromatogr A 905 233-240,2001. 

Figure 7 Relative amounts of selected compounds from 5.5 g of freshly popped popcorn extracted by SFE DI and SFE SPME methods. B, Sulfurol (4-methyl-5-thiazolethanol), a compound with meaty aroma, was most abundantly observed by the SFE DI method. SFE DI, supercritical fluid extraction direct injection SFE SPME, SFE solid-phase microextraction DDMP, 2,3-dihydro 3,5-dimethyl-4(H)-pyran-4-one.

The nature of flavor compounds creates challenges for analysis. Aroma compounds must be volatile. They are usually present at very low concentrations in foods. Despite the fact that hundreds of volatile compounds are often present in a food, only a few may be odor-active. Gas chromatography has been an invaluable tool for separation and subsequent identification of volatile compounds. Concentration of flavor chemicals is often necessary since the compounds are usually present at low levels. Some methods of sample preparation are described in this handbook, including solid-phase microextraction (see Chapters 16, 20-22, 30, and 31), sorptive stir bar extraction (Chapter 32), absorption on a porous polymer (Chapters 21, 22, and 27), super-critical CO2 extraction (Chapter 22), simultaneous steam distillation (Chapter 31), accelerated solvent extraction (Chapter 35), simultaneous distillation extraction (Chapters 21 and 31), and direct gas injection with cryofocusing (Chapter 20). Sampling conditions are considered in Chapters 20, 23, and 24, and comparisons of some chemical detector sensitivities are made in Chapters 18, 23, and 27-29. 

F. Pelusio, T. Nilsson, L. Montanarella, R. TiUo, B. Larsen, S. Facchetti, and J. Madsen, Headspace solid-phase microextraction analysis of volatile organic sulfur compounds in black and white truffle aroma, J. Agiic. Food Chem. 43 2138 (1995). 

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