TITLE:
Influence of Environmental and Microclimate Factors on the Coffee Beans Quality (C. canephora): Correlation between Chemical Analysis and Stable Free Radicals
AUTHORS:
André Luíz Alves, Marcio Solino Pessoa, Paulo Eduardo Narcizo de Souza, Fábio Luís Partelli, Paulo Sérgio Moscon, Edson Correa da Silva, André Oliveira Guimarães, Eduardo Perini Muniz, Patrícia Fontes Pinheiro, Flávio Meira Borém, Paulo César Morais
KEYWORDS:
Sun-Grown Coffee, Shade-Grown Coffee, Fermentation, EPR, FTIR, HPLC
JOURNAL NAME:
Agricultural Sciences,
Vol.9 No.9,
September
28,
2018
ABSTRACT: The present study reports a physicochemical comparison of shade-grown and sun-grown coffee beans, under unripe, rip and roasted-ripe conditions, using electrical conductivity measurements, electron paramagnetic resonance (EPR), infrared spectroscopy (FTIR), and high performance liquid chromatography (HPLC). Moreover, the assessed physicochemical parameters were compared with organoleptic evaluations based on the Coffee Quality Institute protocol. The values found for electrical conductivity, leached potassium, and stable free radicals were respectively 29%, 31%, and 350% higher for shade-grown coffee beans, whereas polyphenol oxidase enzymatic activity was 23% lower. By contrast, FTIR and HPLC measurements identified higher chlorogenic acid and lipid contents in sun-grown coffee beans. Importantly, the sensorial grade attributed to roasted-ripe grains was 12% higher for sun-grown coffee. Our findings suggest that shade-grown coffee beans have undergone microorganismal activity and undesired fermentation during cultivation, which resulted in lower coffee quality. A correlation between a set of selected physicochemical properties and organoleptic properties was robustly established and could be used in the development of future coffee bean quality control protocols.