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--- theobroma_cacao_l [2020/11/30 15:00] – andreas
+++ theobroma_cacao_l [2020/12/06 08:43] (aktuell) – andreas
@@ Zeile 16: / Zeile 16: @@
 "Isolation of the volatile fraction from cocoa powder (50 g; 20% fat content) by a careful extraction/distillation process followed by application of an aroma extract dilution analysis revealed 35 odor-active constituents in the flavor dilution (FD) factor range of 8-4096. Among them, 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel-like), 2- and 3-methylbutanoic acid (sweaty, rancid), dimethyl trisulfide (cooked cabbage), 2-ethyl-3,5-dimethylpyrazine (potato-chip-like), and phenylacetaldehyde (honey-like) showed the highest FD factors. Quantitation of 31 key odorants by means of stable isotope dilution assays, followed by a calculation of their odor activity values (OAVs) (ratio of concentration to odor threshold) revealed OAVs > 100 for the five odorants acetic acid (sour), 3-methylbutanal (malty), 3-methylbutanoic acid, phenylacetaldehyde, and 2-methylbutanal (malty). In addition, another 19 aroma compounds showed OAVs > 1. To establish their contribution to the overall aroma of the cocoa powder, these 24 compounds were added to a reconstructed cocoa matrix in exactly the same concentrations as they occurred in the cocoa powder. The matrix was prepared from deodorized cocoa powder, which was adjusted to 20% fat content using deodorized cocoa butter. The overall sensory evaluation of this aroma recombinate versus the cocoa powder clearly indicated that the 24 compounds represented the typical sweet, cocoa-like odor of the real sample." \\
 [Identification of the key aroma compounds in cocoa powder based on molecular sensory correlations., Frauendorfer, Felix, Schieberle, Peter,  Journal of agricultural and food chemistry, Vol.54(15) 2006, 5521-5529] [[http://worldcocoafoundation.org/wp-content/files_mf/frauendorfer2006.pdf]]
+Character impact compounds of the volatile fraction of three commercial cocoa powders (Bensdorp, Krüger, Sarotti) isolated using thin-layer high-vacuum distillation (TLHVD) of Soxhlet extracts were: Acetic acid (vinegar), propanoic acid (mouldy), 2-methyl propanoic acid (rancid), phenylacetaldehyde (flowery), 2/3-methyl butanoic acid (sweaty), dehydromevalonic acid lactone (condesed milk, sour), 2-pyrrolidinone (popcorn), pyrrole-2-carboxaldehyde (nut), (R)-(−)-pantolactone (caramel, coconut), furaneol (caramel), massoia lactone (coconut), dihydroxymaltol (caramel), 4-methyl-5-(2-hydroxyethyl)thiazol (peanut), two solerol isomers (red fruit, jam, green notes), vanillin (vanilla) and phenylacetic acid (sweet, flowery). These 17 compounds were detected at the sniff port of the GC-O after a 1:100 dilution. The aroma extract contained acetoin and several alkylated pyrazines e.g. \\
+[Krings, Ulrich, et al. "Thin-layer high-vacuum distillation to isolate volatile flavour compounds of cocoa powder." European Food Research and Technology 223.5 (2006): 675-681]
 "Cocoa beans (Theobroma cacao) are the major raw material for chocolate production and fermentation of the beans is essential for the development of chocolate flavor precursors. In this study, a novel approach was used to determine the role of yeasts in cocoa fermentation and their contribution to chocolate quality... Quality tests revealed that beans fermented without yeasts were purplish-violet in color and not fully brown, and chocolate prepared from these beans tasted more acid and lacked characteristic chocolate flavor. Beans fermented with yeast growth were fully brown in color and gave chocolate with typical characters which were clearly preferred by sensory panels. Our findings demonstrate that yeast growth and activity were essential for cocoa bean fermentation and the development of chocolate characteristics." \\
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 "A number of compounds have been identified by gas chromatography-olfactometry (GC-O) as key odorant compounds in dark chocolate. 2-Methylpropanal, 3-methylpropanal and 2-methylbutanal have been related to chocolate odors while trimethylpyrazine, 2,5-dimethylpyrazine and acetylpyrrole have been attributed cocoa odors. Methylpyrazine, 2,3-dimethylpyrazine, 2-ethyl-6-methylpyrazine and benzaldehyde added a hazelnut/almond note to the aroma profile of chocolate; ethylpyrazine, 3-ethyl-2,5-dimethylpyrazine and tetramethylpyrazine a roasty note." \\
 [Evaluation of solid-phase micro-extraction coupled to gas chromatography-mass spectrometry for the headspace analysis of volatile compounds in cocoa products. Ducki, S., Miralles-Garcia, J., Zumbé, A., Tornero, A., Storey, D. M., Talanta, Vol.74(5), 2008, 1166-1174]
+"The specific cocoa aroma arises from complex biochemical and chemical reactions during the postharvest processing of raw beans, and from many influences of the cocoa genotype, chemical make‐up of raw seeds, environmental conditions, farming practices, processing, and manufacturing stages. There has been much research on cocoa flavor components. However, the relationships between all chemical components that are likely to play a role in cocoa flavor, their sensory properties, and the sources and mechanisms of flavor formation are not fully understood." \\
+[Aprotosoaie, Ana Clara, Simon Vlad Luca, and Anca Miron. "Flavor chemistry of cocoa and cocoa products—an overview." Comprehensive Reviews in Food Science and Food Safety 15.1 (2016): 73-91] [[https://onlinelibrary.wiley.com/doi/full/10.1111/1541-4337.12180]]
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