Coffee Science

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2020 - 20242

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Assunto: search.filters.subject.Quality coffee

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Agora exibindo 1 - 2 de 2
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    Exploratory evaluation of dry fermentation of specialty coffee from Nariño-Colombia, -using wet and honey-like methods
    (Universidade Federal de Lavras, 2024-04-30) Guevara, Cindy Estefanía Córdoba; España, Mayerlyn Nathaly Ortega; Solarte, Fernanda Elizabeth Cabrera; Chaves, Erick Fernando Collazos; Troya, Arsenio Hidalgo; Bucheli, Andrés Darío Pantoja; Gutiérrez, Nelson Humberto Hurtado; Romo, Dolly Margot Revelo
    The aim of this investigation was to compare the quality of coffee produced by dry fermentation using wet and honey-type methods in three farms located in southwestern Colombia through an ex post facto study. Specialty coffee was produced and studied according to a post-harvest protocol that utilized traditional practices. The study revealed that the quality of coffee is primarily affected by postharvest processing (57.6%) and the coffee farm (37.9%). The honey-like processing method employed on La Mina farm obtained the highest overall quality score, as determined by the Specialty Coffee Association (SCA). The variation in the cup quality occurred due to the variation in the different attributes. The overall impression, fragrance/aroma, body, and flavor were the primary contributors to the total score quality variance (34.9%), whereas acidity, aftertaste, and balance accounted for 26.1% of the total variance. Regarding the environmental, physicochemical, and microbiological parameters, the principal component analysis showed that the bottom temperature (BT), surface temperature (ST), middle temperature (MT), aerobic mesophilic bacteria (AMB), and °Bx accounted for 29.5% of the variance. Also, yeast, pH, LAB, and AAB accounted for 27.3% of the total variance. The highest correlation with the final cupping score was recorded for MT, ST, environmental temperature (ET), BT, Enterobacteria, and relative humidity (RH). Pre-fermentation was found to increase the microbial count, and longer dry fermentation durations of depulped coffee promoted the growth of beneficial microbial populations. The process revealed interesting relationships between temperature-AMB and degrees Brix (°Bx), and between yeast-lactic acid bacteria (LAB) and acetic acid bacteria (AAB).
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    Comparison of sensory attributes and chemical markers of the infrared spectrum between defective and non-defective Colombian coffee samples
    (Editora UFLA, 2020) Rodriguez, Yeison Fernando Barrios; Calderon, Karen Tatiana Salas; Hernández, Joel Girón
    Defects in coffee affect the sensory quality of finished drink. To avoid this, defective beans are usually removed after threshing, as, once the green beans have been roasted, it becomes difficult to identify the defects. Procedures have been developed to evaluate coffee samples using infrared spectroscopy to detect such defects. As such, this study evaluated infrared spectra and sensory attributes of 39 coffee samples in: commercial ground and instant coffees, medium and high roast quality coffees, and defects present in the coffee. The sensory analysis was performed by 10 judges, semi-trained by a Q-grader, and eleven attributes were assessed using a semi-structured hedonic scale. The spectra obtained from the coffee samples were processed by mean centering, normalization (probabilistic quotient normalization), area normalization, first derivative and second derivative, later followed by principal component analyses. The sensory results showed differences in the evaluated attributes, differentiating between the samples of high quality medium roasted coffee from the other samples. After processing IR spectra of the samples by area normalization, PCA results exhibited four different groups: a) medium, high roasted quality coffee, with broken and chipped defects; b) commercial ground coffee and defects of sour, insect damaged, and faded; c) black defects, and d) instant coffee. Using the chemical descriptors obtained from the infrared spectra, it was possible to separate between high quality, commercial and instant coffee.