Ciência e Agrotecnologia
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/9885
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Item Challengs in coffee quality: cultural, chemical and microbiological aspects(Editora UFLA, 2018-07) Pimenta, Carlos José; Angélico, Caroline Lima; Chalfoun, Sára MariaThe Brazilian coffee industry is undergoing a great transformation in order to serve a consumer market that is becoming increasingly demanding with regard to quality. Considering the multiple determinants of the final quality of the product, one must consider factors that are involved in steps from the pre-harvest stage to storage. The execution of the different stages according to good-practice programmes has repercussions on microbiological, physical and chemical characteristics, which in turn affect the quality of the final product with regard to sensorial properties and safety. There has been research progress in the improvement of quality evaluation techniques that minimize the subjective effects of traditional classification. It is also observed that socio-environmental aspects of coffee production, while not the subject of this review, have broadened the concept of quality since an increasing number of consumers are interested in aspects regarding agricultural sustainability in addition to strictly sensorial aspects.Item Correlation between antioxidant activity and coffee beverage quality by electron spin resonance spectroscopic(Editora UFLA, 2013-11) Barbosa, Jeam Haroldo Oliveira; Luna, Jorge Antonio Gómez; Kinoshita, Angela Mitie Otta; Baffa Filho, OswaldoBrazil is the largest producer of coffee in the world and coffee prices are directly linked to grain quality. In this work, the antioxidant activity of coffee was related to its quality through Electron Spin Resonance Spectroscopy (ESR), as an attempt to establish a non-subjective method to classify the grain quality. For that purpose, the IC50 and temporal monitoring of its non- oxidized fraction were determined for three bean qualities: Soft (High), Hard (Medium) and Rio (Low). Methanolic solution of 2,2- difenil-1-picril-hidrazila (DPPH), that has a stable radical and a JEOL FA-200 (X-Band) spectrometer were used for these tests. The temporal monitoring of reaction between radical and coffee was performed. The rate of reduced or of antioxidated radicals was determined on time and for each coffee beverage quality were found different slopes of curve: Soft (0.32±0.02), Hard (0.47±0.02) and Rio (0.60±0.02). The IC50 result of Rio quality (2.7 ± 0.9) was different from the Soft (7.8 ± 1.9) and Hard (6.5 ± 1.5) values, but there was no difference between the High and Medium results due to the uncertainty associated. Therefore the results found, mainly for monitoring temporal, establish a new quantitative methodology for classifying the coffee beverage quality.