Characterization of the Major Odor-Active Compounds in the Leaves of the Curry Tree Bergera koenigii L. by Aroma Extract Dilution Analysis

Abstract

Curry leaves are a popular seasoning herb with a pronounced sulfury and burnt odor, the molecular background of which was yet unclear. Application of an aroma extract dilution analysis to the volatile fraction of curry leaves isolated by solvent extraction and solvent-assisted flavor evaporation afforded 23 odor-active compounds with flavor dilution (FD) factors ranging from 1 to 8192. On the basis of the comparison of their retention indices, mass spectra, and odor properties with data of reference compounds, the structures of 22 odorants could be assigned, 15 of which had not been reported in curry leaves before. Odorants with high FD factors included 1-phenylethanethiol (FD factor 8192), linalool (4096), α-pinene (2048), 1,8-cineole (1024), (3Z)-hex-3-enal (256), 3-(methylsulfanyl)propanal (128), myrcene (64), (3Z)-hex-3-en-1-ol (32), and (2E,6Z)-nona-2,6-dienal (32). The unique sulfury and burnt odor exhibited by 1-phenylethanethiol in combination with its high FD factor suggested that it constitutes the character impact compound of fresh curry leaf aroma.

Characterization of Odor-Active Compounds, Polyphenols, and Fatty Acids in Coffee Silverskin

“…Dichloromethane, diethyl ether, and pentane were freshly distilled before use. Silica gel 60 (0.040−0.063 mm) was purchased from VWR (Darmstadt, Germany) and purified as described previously [ 48 ]. Mercurated agarose gel was prepared from Affi-Gel 10 (Bio-Rad, Munich, Germany) [ 49 ].…”

“…The eluate was collected in five portions of 50 mL and eluate portions were concentrated to 0.5 mL (NBVA-E). Another SAFE distillate was used to prepare a volatile thiol fraction by following a published procedure [ 48 ]. Briefly, the concentrated volatile extracts of CS and CB were applied onto mercurated agarose gel (1 g) in a glass column (0.5 cm i.d.).…”

Inactivation of Thioglucosidase from Sinapis alba (White Mustard) Seed by Metal Salts

“…Saturated sodium chloride and calcium chloride solutions are known to inactivate enzyme system and they are commonly used in flavor study [ 23 , 24 ]. An alternative method to stop the enzyme reaction is to remove water by using anhydrous sodium sulfate [ 25 ]. However, myrosinase has so far been poorly studied, particularly concerning the volatile analysis and flavor study.…”

Molecular background of the undesired odor of polypropylene materials and insights into the sources of key odorants

“…Silica gel 60 (0.040−0.063 mm) was obtained from VWR and purified as detailed previously. 27 Silicone oil was purchased from Merck, and sunflower oil was bought in a local supermarket.…”

“…The experiments included the 18 compounds previously selected for quantitation in the standard polypropylene material PP-1 (cf. section 3.1.2) plus four additional compounds(16,27,38, 43). The experiments were focused on the samples PP-2, PP-3, PP-6, and PP-7.…”