Coffee Science
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3355
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Resultados da Pesquisa
Item Aroma profiles and cupping characteristics of coffee beans processed by semi carbonic maceration process(Universidade Federal de Lavras, 2023-07-18) Jitjaroen, Wanphen; Kongngoen, Rungtiwa; Panjai, LachineeThe goal is to improve the flavors of Arabica coffee by combining semi-carbonic maceration (SCM) process, with enzymatic process at various lengths and temperature. Five different variations of SCM processes were investigated: pulped natural process (control); at 15 oC for 10 days (SCM-15); at 20 oC for 10 days (SCM-20); with 0.01 g.L-1 pectinases A (polygalacturonase, pectin esterase and pectin lyase) at 20 oC for 5 days (SCM-PA); and with 0.03 g.L-1 pectinases B (polygalacturonase, pectin esterase, pectin lyase and ß-glucanase) at 20 oC for 5 days (SCM-PB). The chemical composition of intact mucilage and green bean coffee were analyzed. The environments created by using SCM fermentation process at 20 oC combined with pectinase A and pectinase B produced green bean coffee with higher content of acidity and reducing sugar. The volatile compounds of roasted coffee were examined by Gas Chromatography-Mass Spectrometry (GC-MS). Fifty-one volatile compounds belonging to 12 chemical classes were identified. The different total peak area, indicates that most volatile compounds, increases during SCM, and SCM process combined with enzymatic method. The Specialty Coffee Association of America; SCAA sensory analysis was performed by trained specialty coffee judges. The final product of coffee beans, which has been treated with SCM process at 15 and 20 oC have obtained the highest score in fragrance, flavor, aftertaste, body, balance and overall impression. While the enzyme treatment has attained the highest scores in acidity. This study demonstrates that the proposed process may be useful for the improvement of the cup quality.Item Characterization of active-aroma wheel in contemporary coffee processes via gas chromatography–olfactometry, and sensory perspective(Universidade Federal de Lavras, 2023-04-28) Jitjaroen, Wanphen; Chaisri, Daorung; Panjai, LachineeThis research is to study the difference in chemical changes during fermentation, between the new fermentation processes. Aroma descriptors and sensorial assessments can be effectively used to tailor made fermentation processes. Coffee cherries (Coffea arabica L. var. Catimor) were treated with three different processes as followed: 1) Dry process (control), 2) Semi-carbonic maceration process (SCM): Carbon dioxide gas was injected to replace oxygen, and 3) Yeast process: coffee cherries were fermented by commercial yeast strain Saccharomyces cerevisiae var cerevisiae. SCM and Yeast processes were both incubated at 17±1oC until mucilage of pulped coffee and pectin layer reached to 4.2-4.3 of pH value. Low air temperatures (20-33 oC), low relative humidity (25-60%) to dry coffee samples to the desired 12.5% moisture content was used. The chemical component of the intact mucilage during fermentation was analyzed. The active-aroma attributes of roasted coffee were qualified and intensified by gas chromatography–olfactometry, categorized as followed: Enzymatic, Sugar browning, Dry distillation and Aromatic, and translated into an active-aroma wheel. The quality cup scores were evaluated by certified Q arabica graders, according to the standard of the Specialty Coffee Association. Results shows that, when compared to Control, SCM and Yeast process had a greater potential when it comes to increasing active-aroma attributes (twenty, twenty-nine, and twenty-two active-aroma attributes respectively). The fermentation process of SCM and Yeast process changes the post fermentation chemical composition of coffee cherry, a decrease in pH value, and an increase in acidity and ethanol. Both processes resulted in an improvement in aromatic attributes of roasted coffee, in both types and intensities. In line with the cup quality’s final scores of 81.50, and 82.83 (specialty coffee), respectively, both processes scored higher than the Dry process (79.42 cup score), with coffee from Yeast process scoring the highest in significant difference.