Teses e Dissertações
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Item Specialty coffees fermented at different altitudes: Influence of yeast co-inoculation on chemical and sensory composition(Universidade Federal de Lavras, 2021-04-26) Bressani, Ana Paula Pereira; Schwan, Rosane Freitas; Simão, João Batista Pavesi; Batista, Nádia NaraSpecialty coffees are gaining more space in the Brazilian market, and the changes in production, processing, marketing, and consumer culture are noticeable. Unquestionably, the use of selected starter cultures in the fermentation process improves the coffee quality. However, the microorganisms' behavior can be different depending on the variety, processing method, and altitude. Thus, this paper aims to (i) use metabolomics, chemical, and sensory methodologies to evaluate the quality of fermented coffees of the cultivar Catuaí vermelho IAC-44 at different altitudes (600 and 1,200 m) located in the Caparaó region. (ii) analyze consumers’ knowledge and perspectives on coffees and investigate how information can influence consumers’ sensory experience. For this, the coffee cherries were harvested manually and separated into batches of 20 kg, representing seven treatments plus control at each altitude. The starter cultures - Saccharomyces cerevisiae CCMA 0543, Candida parapsilosis CCMA 0544, and Torulospora delbrueckii CCMA 0684 - were inoculated, isolated, and in co-inoculation. The control was performed without inoculation. Fermentation of whole fruits lasted 72 h in closed bioreactors. Then, the coffees were transferred to the suspended terraces until 11- 12% moisture. Samples were collected and frozen for chemical analysis. We studied the improving coffee beverage quality cultivated at low altitudes through inoculation of yeast during fermentation in dry processing. The analyzes were performed using liquid and gas chromatography, Fourier transforms infrared spectroscopy (FTIR), and cup testing. Differences in chemical compounds were observed between the inoculated coffees and the control, both for green and roasted beans. Fermentation improved the quality of low-altitude coffees, and the co-inoculation of non-Saccharomyces yeasts (C. parapsilosis CCMA 0544 and T. delbrueckii CCMA 0684) had the highest sensory score (85), being the most suitable for this process. The second topic addressed in this work was the influence of fermentation with starter cultures concerning the bioactive, chemical, and sensory compounds of coffee produced at high altitudes. The content of total polyphenols and antioxidants is strongly correlated with the end of fermentation in a closed bioreactor and after roasting. The trigonelline content has a moderate and negative correlation with fermentation and roasting. Fruity, citric, and wine notes were found only in inoculated treatments. The co-inoculated with the three yeasts showed the highest sensory score (86.9). The third aspect addressed was understanding the perspectives and desires of coffee consumers through a questionnaire in a digital format with 1,005 participants. The chocolate flavor is still the most expected in specialty coffee. The Check-all-that-Apply (CATA) test was carried out with 101 consumers using the same coffee (without and with information). Sensory analysis showed that consumers could be influenced by information. Therefore, co-inoculation of yeasts in coffee fermentation is a promising alternative for low and high-altitude coffee. Also, specialty fermented coffees should be made more widely available to consumers.Item Avaliação química e sensorial de café catuaí amarelo fermentado pelo processamento por via seca com inoculação de leveduras(Universidade Federal de Lavras, 2017-02-15) Bressani, Ana Paula Pereira; Schwan, Rosane FreitasO café é uma bebida popular consumida em todo o mundo e sua qualidade está diretamente relacionada ao sabor e aroma. O objetivo deste estudo foi avaliar a ação de leveduras selecionadas, inoculadas diretamente em diferentes métodos de inoculação (café cereja fermentado por via seca em terreiro suspenso (D) e em baldes, durante 16 horas antes de ser levado para o terreiro suspenso (B)) para secagem ao sol. Saccharomyces cerevisiae CCMA 0543, Candida parapsilosis CCMA 0544 e Torulospora delbrueckii CCMA 0684 foram inoculadas separadamente e o controle sem inoculação. A composição centesimal foi avaliada no fruto do café. Amostras foram coletadas para análise de qPCR (persistência do inóculo) e para análise química por HPLC (cafeína, ácidos clorogênicos, trigonelina ácidos orgânicos e açucares) e GC-MS (compostos voláteis). A análise sensorial foi realizada no café torrado através da prova de xícara, de acordo com Specialty Coffee Association of America (SCAA). Todos os tratamentos com leveduras diretamente inoculadas apresentaram maiores concentrações de ácidos cítrico e málico quando comparados com o método em balde. Concentração de cafeína, ácidos clorogênicos e trigonelina, variaram entre os métodos de inoculação. No total, duzentos e dezessete compostos voláteis foram identificados. Todos os tratamentos originaram cafés especiais, e o tratamento com Saccharomyces cerevisiae 0543 B obteve a pontuação mais alta no teste de xícara, com notas de banana e caju. O tratamento com Candida parapsilosis CCMA 0544 inoculado diretamente foi melhor do que o mesmo tratamento inoculado em balde, e o tratamento com Torulospora delbruekii CCMA 0684 mostrou bons resultados para ambos os métodos utilizados