Biblioteca do Café

URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/1

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Resultados da Pesquisa

Agora exibindo 1 - 3 de 3
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    Metabolomics and sensorial analysis: strategic to selecte new yeast to improve coffee quality
    (Universidade Federal de Lavras, 2023-07-17) Pajoy Trujillo, Manuel Alejandro; Schwan, Rosane Freitas; Batista, Nádia Nara
    Monitoring coffee production processes from cultivation to roasting guarantees an improvement in the final quality of the beverage. Anaerobic fermentation induced by microbial metabolism (SIAF), with or without the addition of starter cultures, helps in the production of specialty coffees. The starter cultures depend on the altitude and region of production, the coffee variety, as well as the processing method. The aim of this study was to evaluate the fermentation performance of potential starter cultures in the natural and pulped processes of the Acaiá cultivar using metabolomic and sensory methodologies. The whole, peeled fruit was sanitized with peracetic acid (520 ppm). Fermentations were carried out by inoculating the yeasts Meyerozyma caribbica (CCMA 1993, CCMA 1950, CCMA1992, CCMA 1617, CCMA1635), Hanseniaspora uvarum (CCMA 1944), Pichia kluyveri (CCMA1658), Meyerozyma guillermondii (CCMA1737), Cystofilobasidium ferigula (CCMA1647) and control in bioreactors (5L) in duplicate. Fermentation was carried out for 168 hours for the natural process and 144 hours for the pulped process. In the controls for each process, yeast isolations were carried out on YEPG agar at pH 3.2. The isolates were identified using MALDI-TOF. High performance liquid chromatography (HPLC) detected citric, tartaric, succinic, lactic and acetic acids, as well as ethanol, in both processes. The volatile compounds were analyzed by gas chromatography-mass spectrometry (GC-MS), where 97 compounds were detected in the pulped coffee and 118 in the natural coffee, highlighting the production of alcohols, esters, pyrazines and furans. The pulped process has notes of orange, tropical fruit and woodiness, while the natural process has chocolatey notes. In this research, strains such as Hanseniaspora uvarum (CCMA 1944), Pichia kluyveri (CCMA1658), Meyerozyma guillermondii (CCMA1737) and Meyerozyma caribbica (CCMA1735) can be indicated as suitable for fermentation in the natural process, while Hanseniaspora uvarum (CCMA 1944) and Meyerozyma caribbica (CCMA1735) are suitable for fermentation in the pulped process.
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    Use of Cladosporium sp. as a bioprotector of coffee quality in different post-harvest conditions
    (Universidade Federal de Viçosa, 2023-11-13) Paiva, Felipe Aparecido de; Melo, Bruno Manoel Rezende de; Ferreira, Sindynara; Oliveira, Emanuelle Morais de; Santos, Telma Miranda dos; Castro, Douglas Goulart
    The pre-harvest application of the bioprotective agent Cladosporium cladosporioides is an alternative to inhibit these fermentative processes that might occur in coffee beans that were either their storing bag or exposed to simulated rain, because a controlled amount of water was applied to the coffee. The objective of this study was to evaluate the effect of Cladosporium cladosporioides (Fresen) de Vries in the physical-chemical and sensory of the coffee beans. The study was conducted in an arabica coffee plantation, in the municipality of Inconfidentes, state of Minas Gerais, Brazil. In this study used four different doses of the bioprotector and three different pos-harvest conditions. The sour defective coffee beans, electrical conductivity, total titratable acidity, soluble solids, color and it was determined the general quality of coffee of both the left-in-bag and rainfall-exposed variants were positively influenced by the bioprotector. The bioprotector promoted an increase in the quality of the physical and chemical composition and sensory quality of rainfall and left-in-bag coffees compared to coffee beans without bioprotector. The bioprotector also maintained quality in rainfall and left-in-bag coffee when compared with the yard-grown variant. The sensory quality of the yard-grown coffeed was not influenced by the bioprotector.
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    Analysis and technical optimization of processing condition for better quality of robusta coffee production
    (Universidade Federal de Lavras, 2023-06-06) Ahmad, Usman; Sa’diyah, Khalimatus; Sathivel, Subramaniam
    The wet processing of robusta coffee starts with harvesting coffee cherries, followed by sorting the cherries, pulping, fermentation, washing, drying, hard skin hulling, bean sorting, and packaging. Soaking fruit before pulping is an alternative for coffee farmers to delay the pulping process if time does not allow it. The fermentation process aims to remove mucus that is firmly attached to the hard skin. The addition of L. casei microbes can accelerate the process but affect the final taste. The study aimed to optimize the duration of soaking and fermentation processes for obtaining coffee beans with a minimum number of unpeeled beans, minimum partially black bean value, maximum taste quality, and to identify volatile components that play a role in forming the best steeping aroma after the coffee beans are roasted, ground and brewed. Experiments and data analysis were carried out using the Response Surface Method design. The optimization results showed that 24 hours of soaking and 24 hours of fermentation were the optimum treatment based on the criteria for unpeeled beans response, partially black bean value, and total taste score with a desirability value of 0.721. The identified volatile compounds (43) include 9 aldehyde group compounds, 3 alcohols, 4 furans, 5 heterocyclic N, 6 ketones, 1 organic acid, 3 phenols, 10 pyrazines, and 2 thiols. The spicy and chocolaty aroma produced was also the highest among treatments, namely 8.98% and 7.74%. The treatment without soaking and fermentation had the highest percentages of caramelly and nutty areas, namely 23.14% and 21.35%, respectively.