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The aim of this work was to assess the geographic distribution of coffee quality in Minas Gerais state, Brazil, and to study its interactions with chemical and environmental factors. Correlations between environmental factors, chemical compounds and sensory quality of participants of the Minas Coffee Quality Contest were made through Principal Component Analysis and Biplot Graphics. The results showed discriminations of high and low scores as a result of environmental variables, demonstrating a strong influence of temperature, rainfall, altitude and latitude on the quality of the coffees studied. In addition to the environmental characteristics, the chemical compounds trigonelline, caffeine, and especially the acid-5-cafeiolquinic were also relevant in discriminating the scores obtained through sensory analysis. This work is an initial indication of the factors that determine the quality of coffees produced in Minas Gerais.

The goal of this work was to select the best combination of encapsulants for the microencapsulation of oregano essential oil by spray dryer with the addition of Arabic gum (AG), modified starch (MS) and maltodextrin (MA). The simplex-centroid method was used to obtain an optimal objective function with three variables. Analytical methods for carvacrol quantification, water activity, moisture content, wettability, solubility, encapsulation efficiency (ME) and oil retention (RT) were used to evaluate the best combination of encapsulants. The use of AG as a single wall material increased ME up to 93%. Carvacrol is the major phenolic compound existent in the oregano essential oil. Carvacrol exhibits a maximum concentration of 57.8% in the microparticle with the use of 62.5% AG and 37.5% MA. A greater RT (77.39%) was obtained when 74.5% AG; MS 12.7% and 12.7% MA were applied, and ME (93%) was improved with 100% of gum.

The Bourbon coffee cultivar has a high potential for producing a quality beverage, which is highly valued in specialty coffee markets. The objective of this study was to verify the occurrence of more promising genotypes for the production of specialty coffees in three different environments. In addition, the chemical composition of the grains was studied with a view toward relating these compounds to the genotypes and environments and to the interaction of these factors.The experimental design included three Brazilian locations in combination with different Arabica coffees, including eleven bourbon and three commercial genotypes. Trigonelline, caffeine and 5-caffeoylquinic acid (5-CQA) from coffee bean samples were analyzed by HPLC, and sensory analyses were performed by professional cuppers accredited by the Coffee Quality Institute. A group of Bourbon genotypes with potential for the production of specialty coffees was identified for each environment assessed. The trigonelline content allowed for discrimination among the three environments studied.

ABSTRACT. The objective of this study was to evaluate the correlation between a group of physiological variables (electrical conductivity, potassium leaching, and germination percentage) and a group of drying kinetics variables (drying time and drying rate) in addition to verifying the relation between drying kinetics variables and coffee quality as a function of processing type, temperature, and drying airflow. Coffee drying was conducted in a fixed-layer dryer at two temperatures and two airflows. After drying, an evaluation of the physiological and sensorial quality was conducted. Based on the results obtained, the following conclusions were drawn: coffee that is processed via a dry method is more sensitive to mechanical drying with heated air than coffee processed via a wet method, resulting in poor physiological performance; airflow does not interfere with the physiological quality of pulped and natural coffees; a temperature increase from 40 to 45°C resulted in a decrease in the physiological quality only for pulped coffee; and an increase in the drying rate as a result of an increase in the drying temperature to 40°C had a negative effect on the sensorial quality of pulped coffee.Keywords: drying kinetics, processing, drying rate.Qualidade fisiológica e sensorial do café arábica submetido a diferentes temperaturas e fluxos de ar de secagem RESUMO. Este trabalho foi realizado com o objetivo de avaliar a correlação entre um grupo de variáveis fisiológicas (condutividade elétrica, lixiviação de potássio e porcentagem de germinação) e um grupo de variáveis de cinética de secagem (tempo e taxa de secagem), bem como verificar a relação entre as variáveis de cinética de secagem e a qualidade sensorial do café, em função do tipo de processamento, da temperatura e do fluxo de ar de secagem. A secagem do café foi realizada em secador de leito fixo com duas temperaturas e dois fluxos de ar. Após a secagem, foi avaliada a qualidade fisiológica e sensorial. A partir dos resultados obtidos, conclui-se que: o café processado via seca é mais sensível à secagem mecânica com ar aquecido do que o processado via úmida, apresentando pior desempenho fisiológico; o fluxo de ar não interfere na qualidade fisiológica do café despolpado e natural; a elevação da temperatura de 40 para 45°C resultou em queda da qualidade fisiológica apenas para o café despolpado e a elevação da taxa de secagem, por meio da elevação do fluxo de ar de secagem, para a temperatura de 40°C teve efeito negativo na qualidade sensorial do café despolpado.Palavras-chave: cinética de secagem, processamento, taxa de secagem.

IntroduçãoO pequi é um fruto sazonal com safra entre os meses de novembro e fevereiro, dependendo da região (LORENZI, 2000). Por ser fonte de renda da população do cerrado, pesquisadores têm desenvolvido projetos voltados para o processamento da polpa de pequi e a fabricação de conservas, além do congelamento tradicional da polpa (LIMA, 2006), com o objetivo de diminuir a deterioração e a descaracterização do sabor da polpa.O pequi é rico em carotenoides (AZEVEDO-MELEIRO; RODRIGUEZ-AMAYA, 2004; LIMA, 2006;OLIVEIRA et al., 2006;HELOU, 1993), que possuem importantes funções biológicas no ser humano, atuando na prevenção de alguns tipos de câncer, na inibição das mucosas contra úlceras gástricas, na capacidade de prevenir a fotossensibilização em certas doenças de pele, no aumento da resposta imunológica a determinados tipos de infecção e nas propriedades antienvelhecimento (COLDITZ et al., 1985;RODRIGUEZ-AMAYA, 1985;OLSON, 1989). Além disso, alguns carotenoides apresentam atividade como vitamina A (RAMOS, 1991; RODRIGUEZ-AMAYA, 1993a) e protetores de óleos e gorduras, por serem considerados sequestradores de oxigênio, oxidando-se preferencialmente (RODRIGUEZ-AMAYA, 1993b).Cuidados especiais com relação aos métodos de processamento e armazenamento de alimentos devem ser levados em conta devido à grande instabilidade dos carotenoides. Por causa de seu alto grau de insaturação, são susceptíveis à isomerização e oxidação (O' BRIEN, 2004;RAMOS, 1991;RODRIGUEZ-AMAYA, 1993b). A exposição dos carotenoides ao calor, ao oxigênio, à luz, acidez elevada e à baixa atividade de água são fatores que podem levar a mudanças estruturais, reduzindo assim sua atividade (RODRIGUEZ-AMAYA, 1993b). AbstractPequi (Caryocar brasiliense Camb) has stood out for being an oleaginous fruit rich in carotenoids. Drying is widely used technique in the oil extraction process using hexane, but the degradation of oil and carotenoids may occur. The objective of this study was to evaluate the influence of different drying methods (sun, air-circulated drier at 40 and 60 °C) and time (4 hours and up to constant weight) on the yield and quality of the oil extracted using hexane using a soxhlet apparatus. When the pequi pulp was dried up to 3% or even lower, more oil yield was obtained (52-59%, dry basis). The total carotenoids contents obtained were higher and the peroxide index was lower for the pulp dried at 40 °C in an air-circulated drier when compared to drying at 60 °C in an air-ventilated drier and to sun drying technique. These results indicate that drying in an air-circulated drier at 40 °C for 19 hours resulted in higher oil yields with less heat degradation.

Osmotic dehydration using different polyols was studied. Yacon slices were immersed in solutions of xylitol, maltitol, erythritol, isomalt and sorbitol. The kinetics of solid gain (SG), water loss (WL) and water activity (aw) were evaluated (0, 10, 30, 45, 60, 90 and 120 min). The effective diffusion coefficients of water (Deffw) and solids (Deffs) were calculated with the models of Fick and Barbosa Júnior et al. At the end of the process, the highest SG was obtained with erythritol solutions; the lowest with sorbitol and maltitol and intermediate values of SG were acquired in osmotic processes with solutions of isomalt and xylitol. The samples treated in sorbitol, xylitol and erythritol solutions presented the highest Deffw and were more effective at increasing WL and reducing aw. The model of Barbosa Júnior et al. presented the best fitness. The Deffw/Deffs ratio showed better results for osmotic processes involving sorbitol and xylitol. Practical Applications Yacon tuber is typical from Latin America. It is considered an important source of fructooligosaccharides (FOS). This class of carbohydrate is employed on the control of diseases such as obesity and diabetes, due its low glycemic index. However, yacon roots are highly perishable and techniques for conservation are required. Osmotic dehydration is a pretreatment process that provides partial water removal from a food product, with low energy consumption. Polyols are widely employed as osmotic agents due their low caloric value. The kinetics of mass transfer on osmotic process are function of process variables, sample matrix characteristics, molecular weight of osmotic agents and others. This study investigate the water loss, solid gain, effective diffusivity and water activity of the OD of yacon with five different polyols and provide information about mass transfer kinetics of osmotic processes using two different empirical models.

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