Aroma extract dilution analysis

Aroma compounds, 11 517 Aroma extract dilution analysis (AEDA), 11 519-520... 

Blank I, Grosch W, Evaluation of potent odorants in dill seed and dill herb Anethum graveolens L.) by aroma extract dilution analysis,Sci 56 63-67, 1991. 

Nishimura, O. Identification of the characteristic odorants in fresh rhizomes of ginger (Zingiber officinale Roscoe) using aroma extract dilution analysis and modified multidimensional gas chromatography-mass spectroscopy. J Agr Food Chem 1995 43(11) 2941-2945. 

Twenty-nine odour-active compounds were detected by using aroma extract dilution analysis (AEDA) [60]. The results of AEDA together with GC-MS analysis showed ethyl 2-methylbutanoate (described as fruity flavour), followed by methyl 2-methylbutanoate and 3-methylbutanoate (fruity, apple-like), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (sweet, pineapple-like, caramel-like), d-decalactone (sweet, coconut-like), l-( ,Z)-3,5-undecatriene (fresh, pineapple-like), and a unknown compound (fruity, pineapple-like) as the most odour-active compounds. 

However, a single GC-O run only is usually insufficient to distinguish between the potent odorants that most likely contribute strongly to an aroma and those odorants that are only components of the background aroma. Therefore, to improve the results, two methods, combined hedonic aroma response measurements (CHARM) analysis [4] and aroma extract dilution analysis (AEDA) [5, 6] have been developed. As discussed in Sect. 16.4 in both methods serial dilutions of food extract are analysed by GC-O. 

Fig. 16.2 Flavour dilution (FD) chromatogram obtained by application of aroma extract dilution analysis on an extract prepared from parsley leaves. The odorants were identified as 1 methyl 2-methylbutanoate, 2 myrcene, 3 l-octen-3-one, 4 (2)-l,5-octadien-3-one, 5 2-isopropyl-3-me-thoxypyrazine, 6p-mentha-l,3,8-triene, 71inalool, 8 2-sec-butyl-3-methoxypyrazine, 9 (.Z)-6-dece-nal, 10 / -citronellol, 11 ( , )-2,4-decadienal, 12 / -ionone, 13 myristicin, 14 unknown. RI retention index. [30, 31]...

Flavorzyme is a commercially available proteolytic enzyme preparation by Novo Nordisk Bioindustrials. It can be used to obtain a meat-like process flavouring from defatted soybean meal. With the help of aroma extract dilution analysis, Wu and Cadwallader [61] showed in their study of 2002 the presence of key aroma compounds of roasty, meat-like aroma in the enzymatically hydrolysed and heated hydrolysed protein, e.g. maltol, furaneol, methanethiol and furanthiol derivatives. 

Grosch, W. 1993. Detection of potent odorants in foods by aroma extract dilution analysis. Trends Food Sci. Technol. 4 68-73. 

Gas chromatography/olfactometry (GC/O) based on dilution analysis (e.g., CharmAna-lysis or Aroma Extraction Dilution Analysis) gives an indication of what compounds are most potent in the aroma of foods. The application of SPME to GC/O dilution analysis can be achieved by varying the thickness of the fiber phase and the length of exposure, resulting in various absorbant volumes. 

Grosch, W. 1994. Determination of potent odourants in foods by aroma extraction dilution analysis (AEDA) and calculation of odour activity values (OAVs). Flavour Fragrance J. 9 147-158. 

At a meeting in Germany in 1983, the idea of using repeated sniffs of sequentially diluted samples, now generally called dilution analysis, was proposed (Acree and Barnard, 1984). This led to the publication of CharmAnalysis in 1984 and Aroma Extract Dilution Analysis (AEDA) in 1987, both of which were based on the idea of quantifying potency by dilution to threshold. Potency here is similar to the concept of titer or the amount of dilution necessary to... 

ACS American Chemical Society AED atomic emission detection AEDA aroma extract dilution analysis AMC 7-amido-4-methylcoumarin ANS anilinonapththalene sulfonate AOAC Association of Official Analytical Chemists... 

Figure 6. Illustration of the static headspace/aroma extract dilution analysis (SHA) [adapted from Guth and Grosch, Annual report of the Deutsche Forschungsanstalt fur Lebensmittelchemie 1993, p. 27],...

Ferreira, V., Lopez, R., and Aznar, M. (2002). Olfactometry and aroma extract dilution analysis of wines. In Analysis of Taste and Aroma", J. Jackson and H. F. Linskens, (Eds), pp. 89-122. Springer-Verlag, Berlin. 

In order to evaluate the best temperature and time of baking process, Silva et al. (2008) used an expert panel to analyze seven descriptors, including dried fruit, nutty, baked, oak, mushroom, and brown sugar. The optimal temperature and time of baking process respecting the specificity of Madeira winemaking are considered 45 °C for 4 months. On the basis of aroma extract dilution analysis (AEDA), several Maillard byproducts, such as Sotolon, 2-furfural, 5-methyl-2-furfural, 5-ethoxy-methyl-2-furfural, methional, and phenylacetaldehyde, were identified in both Malvasia and Sercial wines under study which may explain the baked, brown sugar, and nutty odor descriptors. 

Ferreira, V., Ortin, N., Escudero, A., Lopez, R., and Cacho, J. (2002b). Chemical characterization of the aroma of Grenache rose wines. Aroma extract dilution analysis, quantitative determination and sensory reconstitution studies. J. Agri. Food Chem. 50,4048—4054. 

The composition of the volatile fraction of bread depends on the bread ingredients, the conditions of dough fermentation and the baking process. This fraction contributes significantly to the desirable flavors of the crust and the crumb. For this reason, the volatile fraction of different bread types has been studied by several authors. Within the more than 280 compounds that have been identified in the volatile fraction of wheat bread, only a relative small number are responsible for the different notes in the aroma profiles of the crust and the crumb. These compounds can be considered as character impact compounds. Approaches to find out the relevant aroma compounds in bread flavors using model systems and the odor unit concept are emphasized in this review. A new technique denominated "aroma extract dilution analysis" was developed based on the odor unit concept and GC-effluent sniffing. It allows the assessment of the relative importance of the aroma compounds of an extract. The application of this technique to extracts of the crust of both wheat and rye breads and to the crumb of wheat bread is discussed. 

The aroma extract dilution analysis of concentrates prepared from the crusts of wheat and rye breads revealed fourty-three odorants in rye and thirty-two in wheat extracts (37). 

If more exact data are desired, the results obtained by aroma extract dilution analysis must be complemented by quantitative measurements. Quantification of odorants is a difficult task, since the concentration of the odorants showing high FD-factors can be extraordinarily low. 

The aroma extract dilution analysis was applied to extracts obtained from the crumb of wheat bread. Twenty nine odorants were detected and the flavor compounds responsible for the odor notes identified (Schieberle, P. Grosch, W. in preparation). The 12 aroma compounds having the highest FD-factors are presented in Table IV. 

Table IV. Important Odorants (FD 32) of Wheat Bread Crumb Results of an Aroma Extract Dilution Analysis and Identification Experiments (Schieberle, P Grosch, W. in preparation)...

In addition, the influence of baker s yeast on the composition of other crust flavor compounds was followed by an aroma extract dilution analysis. 

Crust volatiles were isolated immediately after baking by extraction with dichloromethane and sublimation in vacuo ( ). Application of aroma extract dilution analysis 6) to the acid-free crust extract led to the detection of 31 odorants. After separation and enrichment, these compounds were identified by comparison of the MS/EI, MS/Cl and retention data on two columns of different polarity to reference compounds. Aroma quality was also assessed. The results of the identification experiments (Table I) revealed that 2(E)-none-nal (No. 1), followed by 2(E),4(E)-decadienal (No. 2) and 3-methyl-butanal (No. 3) showed the highest FD-factors in the crust of the chemically leavened bread. Additionally l-octen-3-one, 2(Z)-nonenal, 2(E),4(E)-nonadienal and an unknown compound with a metallic odor contributed high FD-factors to the overall flavor (For a discussion of FD-factors, see Chapter by Schieberle and Grosch, this book). 

The volatiles of fresh leaves, buds, flowers and fruits were isolated by solvent extraction and analysed by capillary gas chromatography-mass spectrometry. Their odour quality was characterized by gas chromatography-olfactometry—mass spectrometry (HRGC-O-MS) and aroma extract dilution analysis (AEDA). In fresh bay leaves, 1,8-cineole was the major component, together with a-terpinyl acetate, sabinene, a-pinene, P-pinene, P-elemene, a-terpineol, linalool and eugenol. Besides 1,8-cineole and the pinenes, the main components in the flowers were a-eudesmol, P-elemene and P-caryophyllene, in the fruits (EJ-P-ocimene and biclyclogermacrene, and... 

Odor-active components in cheese flavor, many of which are derived from milk lipids, can be detected using GC-olfactometry (GC-O). GC-0 is defined as a collection of techniques that combine olfactometry, or the use of the human nose, as a detector to assess odor activity in a defined air stream post-separation using a GC (Friedich and Acree, 1988). The data generated by GC-0 are evaluated primarily by aroma extract dilution analysis or Charm analysis. Both involve evaluating the odor activity of individual compounds by sniffing the GC outlet of a series of dilutions of the original aroma extract and therefore both methods are based on the odor detection threshold of compounds. The key odourants in dairy products and in various types of cheese have been reviewed by Friedich and Acree (1988) and Curioni and Bosset (2002). 

These methods were developed to quantify and visualize the intensity of aroma as a chromatogram. A specific system named combined hedonic and response measurement (CHARM) was initially developed. Later on, aroma extract dilution analysis (AEDA) (Figure 3), a new method using a conventional GC-O system, was proposed. They share the same strategy aroma extract is diluted to a certain extent and then GC—O methodology is applied. In an AEDA procedure, if such a maximum extent of a dilution that allows the detection of a certain component is times diluted from the original sample, this component is referred to have a flavor dilution (FD) factor of . CHARM value corresponds to FD factor in a CHARM procedure. These values represent the contribution of the volatile the larger these values are, the more important they are considered as key components. 

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