Difference Spectroscopy in the Analysis of the Effects of Coffee Cherry Processing Variables on the Flavor of Brewed Coffee

Infrared difference spectroscopy was used to study how changes in the processing of Arabica coffee cherries into green beans affected the flavor of coffee brewed from roasted green beans. Paired samples of green beans, in which the drying step or fermentation/washing step in their processing was altered, were roasted and brewed in a standard manner and their ATR-FT-IR spectra obtained. Difference spectra of the 1800 to 1680 cm−1 carbonyl region of water-subtracted spectra of paired samples of these brewed coffees provided data which indicated differences in brewed coffee flavor due to changes in fermentation/washing steps and drying steps involved in the processing of coffee cherries. The role of acid, ketone, aldehyde, ester, lactone, and vinyl ester carbonyl components on the flavor of brewed coffee is proposed that is consistent with the flavors as perceived by the coffee tasters.

A One-pot Synthesis of Novel Functionalized (E)-β-Arylvinyl Bromides from anti-2,3-Dibromo-3-(4-carboxyphenyl)propanoic Acid

A facile one-pot synthesis of functionalized (E)-β -arylvinyl bromides bearing various 4-alkoxycarbonyl and 4-aryloxycarbonyl groups was achieved by debrominative decarboxylation of anti-2,3- dibromo-3-(4-carboxyphenyl)propanoic acid in the presence of AgOAc and subsequent esterification in the presence of dicyclohexyl carbodiimide and dimethylaminopyridine. This method gives (E)-β - arylvinyl bromides in high stereoselectivities and high yields, and tolerates aldehyde, ester, and nitro functional groups.

CD-Spectroscopic Confirmation of the Absolute Configuration of a Conformationally Flexible Aldehyde Ester Containing a Quarternary Stereogenic Center

The absolute configuration of the conformationally flexible aldehyde ester methyl-2-formyl-2-(phe-nylsulfanyl)-3-(3,4,5-trimethoxyphenyl)-propanoate was determined by comparison of measured and calculated CD spectra.The spectra were calculated by means of the so-called matrix method assuming R configuration at the stereogenic center. Calculated and observed signs of the first three most intense CD bands agree. Therefore, it was concluded that the absolute configuration of the compound was also R, which is in perfect agreement with the results of an X-ray structure determination.