Effects of Roast Levels on the Physical Properties, Microbial Contaminants, and Cup Quality of Arabica Coffee

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Andres A. Basalong Von Y. Amado Hazen Lyn B. Talbino


Turning raw green coffee beans into roasted coffee beans and other products cannot be completed without the roasting process. However, information on the influence of roast levels on the essential qualities of Arabica coffee is scant. This study was conducted to determine the effects of roast levels on the physical properties, microbial contaminants, and cup quality of Arabica coffee. Wet processed BSU-Red Bourbon Arabica coffee green coffee beans were roasted in a 250g-capacity drum-type roaster at three roast levels: light, medium, and dark. The changes in physical properties such as roasted bean dimensions and volume, roast volume, weight loss, and bulk density were observed and analyzed. Results indicated that dark roasted coffee had the highest change in bean size and volume, roast volume, weight loss, and lowest bulk density. Fungal species Saccharomyces cerevisiae and Penicillium sp. were found in the green coffee beans before roasting but were not detected in the roasted coffee beans. Arabica coffee roasted in the three roast levels were all classified as specialty although medium roast scored better than light and dark roasts. The result can be used as a guide in enhancing the development of roasted coffee products towards satisfaction in the consumption of quality Arabica coffee.

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