scholarly journals Improvement of Robusta Coffee Aroma with L-leucine Powder

2022 ◽  
Author(s):  
Kwang-Geun LEE ◽  
Ara Jo ◽  
Hyunbeen Park ◽  
Jooyeon Park ◽  
Seungwoo Ha ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Volatile Compounds ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Aroma Compounds ◽  
Selective Detection ◽  
Total Volatile ◽  
Robusta Coffee ◽  
Coffee Beans

Abstract L-leucine powder (LP) were added to improve the aroma of Robusta coffee beans. Treatment was a short soaking (M1) or spraying procedure (M2), then LP was added at varying levels up to 3% (w/w). All samples were roasted (240 °C/15 min) and extracted using an espresso machine. Volatile compounds were analysed by solid-phase microextraction−gas chromatography−mass selective detection. Thirty volatile compounds (6 pyrroles, 8 pyrazines, 3 phenols, 9 furans, 2 ketones, 2 aldehydes) were analysed. In 15 coffee samples, the levels of total volatile compounds (based on peak area ratios) ranged from 8.9 (M1-1) to 15.5 (non-treated Robusta: NTR). Robusta coffee has lower levels of bitter aroma compounds when pre-treated with LP. The sum of bitter volatiles (phenols, pyrroles, pyrazines) was lowest in M1-5 (3% LP), M2-1 (1% LP; both dried at 50 °C/15 min) and M2-7 (3% LP, dried at 70 °C/15 min) compared with NTR (p < 0.05).

scholarly journals Determination of Volatile Compounds in Foxtail Millet Sake Using Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jingke Liu ◽  
Wei Zhao ◽  
Shaohui Li ◽  
Aixia Zhang ◽  
Yuzong Zhang ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Sample Preparation ◽  
Volatile Compounds ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Foxtail Millet ◽  
Diethyl Ester ◽  
Fiber Types ◽  
Headspace Solid Phase Microextraction ◽  
Spme Fiber

The volatile compounds in foxtail millet sake were extracted by headspace solid-phase microextraction (HS-SPME) and analyzed using gas chromatography-mass spectroscopy (GC-MS). Different methods of sample preparation were used to optimize this method (SPME fiber types, sample amount, extraction time, extraction temperature, content of NaCl, and rotor speed). For final method of sample preparation, 8 mL of sake was placed in a 15 mL headspace vial with addition of 1.5 g of NaCl; a 50/30 μm DVB/CAR/PDMS SPME fiber was used for extraction at 50°C for 30 min with 10 rpm continuous stirring. A total of 41 volatile compounds were identified from the sake sample, including 9 esters, 6 alcohols, 4 acids, 4 aldehydes, 9 hydrocarbons, 7 benzene derivatives, and 2 others. The main volatile compounds were ethyl acetate, phenylethyl alcohol, butanedioic acid diethyl ester, and hexadecane. According to their odors active values (OAVs), 10 volatile compounds were established to be odor active compounds and to contribute to the typical foxtail millet sake aroma. Hexanoic acid ethyl ester was the most prominent odor active compound.

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