Quantitative and Qualitative Evaluation of Fatty Acids in Coffee Oil and Coffee Residue

摘要

This study aimed to investigate the effects of roasting conditions and brewing on coffee oil quality and quantity to gain a basic understanding of coffee residue utilization. The fatty acid composition of the coffee oil extracted from roasted coffee bean and residue was analyzed. The optimum extraction time of whole coffee oil was six-hours using the Soxhlet method with hexane as a solvent. Roasting conditions influenced the extraction ratio of coffee oil, and the extraction ratio increased from 9.8 to 15.9 ％ when the roasting level was increased from light roast (211 °C for 10 min) to dark roast (230 °C for 12 min). On the other hand, the ratio of extracted oil from the coffee residue after brewing was 5.9 ％, which was 50 ％ of the total coffee oil before brewing. The fatty acid composition of coffee oil was determined by GC/F1D, and results indicated that the fatty acid composition between different roasting conditions and coffee residue did not differ significantly. The primary fatty acids were found in all samples and consisted of myristic (C14:0), palmitic (C16:0), stearic (C18:0), oleic (C18:l), linoleic (C18:2), linolenic (C18:3), and arachidic (C20:0) acid.