Jo Ara, Park Hyunbeen, Lee Seongho, Lee Kwang-Geun
Department of Food Science and Biotechnology, Dongguk University-Seoul, Goyang-si, Republic of Korea.
J Sci Food Agric. 2023 May;103(7):3501-3509. doi: 10.1002/jsfa.12485. Epub 2023 Feb 15.
l-Leucine powder (LP) was added to green Robusta coffee beans in order to reduce the difference in flavour between Robusta and Arabica coffee. l-Leucine was selected as an additive based on the Maillard reaction. The pre-treatment method conducted in this study was a short soaking (M1) or spraying procedure (M2), then LP was added at varying levels up to 3% (w/w, 30 g kg ). All samples were roasted (240 °C for 15 min) and extracted using an espresso machine. Volatile compounds were analysed by solid-phase microextraction-gas chromatography-mass selective detection.
Thirty volatile compounds (six pyrroles, eight pyrazines, three phenols, nine furans, two ketones, two 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. Non-treated Robusta had higher levels of bitter aroma compounds than Arabica coffee, and Robusta coffee had 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 for 15 min) and M2-7 (3% LP, dried at 70 °C for 15 min) compared with non-treated Robusta (P < 0.05).
From the results of this study it can be shown that pre-treatment with LP can improve the flavour of Robusta. © 2023 Society of Chemical Industry.
将L-亮氨酸粉末（LP）添加到罗布斯塔生咖啡豆中，以减少罗布斯塔咖啡和阿拉比卡咖啡之间的风味差异。基于美拉德反应选择L-亮氨酸作为添加剂。本研究采用的预处理方法为短时间浸泡（M1）或喷雾处理（M2），然后添加不同水平的LP，最高可达3%（w/w，30 g/kg）。所有样品均进行烘焙（240℃，15分钟），并使用意式浓缩咖啡机进行萃取。通过固相微萃取-气相色谱-质量选择性检测分析挥发性化合物。
分析了30种挥发性化合物（6种吡咯、8种吡嗪、3种酚类、9种呋喃、2种酮类、2种醛类）。在15个咖啡样品中，总挥发性化合物水平（基于峰面积比）在8.9（M1-1）至15之间。未处理的罗布斯塔咖啡比阿拉比卡咖啡含有更高水平的苦味香气化合物，而用LP预处理的罗布斯塔咖啡苦味香气化合物水平较低。与未处理的罗布斯塔咖啡相比，苦味挥发物（酚类、吡咯、吡嗪）的总和在M1-5（3%LP）、M2-1（1%LP；均在50℃干燥15分钟）和M2-7（3%LP，在70℃干燥15分钟）中最低（P<0.05）。
从本研究结果可以看出，用LP预处理可以改善罗布斯塔咖啡的风味。©2023化学工业协会。
