Proteomic Analysis of Natural and Demucilaged Coffee Beans from Plantations at Different Altitudes in the Mantiqueira Mountains

Abstract

Analysis of the effects of climatic conditions and processing methods on coffee beans is of great interest in research, chemical composition and consequent beverage quality are strongly influenced by growing conditions and/or processing methods. Aims: In this study, beans of Coffea arabica cv. Acaiá coffee trees grown at two altitudes (below 1000 m and above 1200 m) were assessed through a proteomic approach in an attempt to better understand the protein changes that occur during two types of processing (dry and wet processing). Methodology: Samples of proteins of natural and demucilaged coffee bean were analyzed by two-dimensional electrophoresis. The gels stained with Commassie Blue G250 were evaluated by the ImageMaster 2D Platinum 7.0 program. The differentially abundant proteins were treated with the enzyme Trypsin e aliquots of each hydrolysate sample were analyzed by mass spectrometry. Sample molecular mass profile obtained through MS e MS/MS was subjected to comparative analysis using the MASCOT program, Brazilian Coffee Genome database, NCBI and Coffee Genome Hub. Place and Duration of Study: The experiments were conducted in the following laboratories: the Laboratório Central de Biologia Molecular (LCBM) and the laboratório de Processamento de Produtos Agricolas (LPPA) at Federal University of Lavras, (Brazil),  between 2014 and 2017. Results: Differentially accumulated proteins, such as 11S globulin, glyceraldehyde-3-phosphate dehydrogenase, dehydrin, and Heat shock proteins, have been found among treatments through mass spectrometry. Conclusion: These results contribute to an understanding of the effects of altitude and processing methods on the chemical composition of coffee beans, and thus serve as a basis for future research related to coffee beverage quality.