STUDY OF THE YIELD AND FATTY ACID PROFILE OF COFFEE (Coffea arabica) OIL FROM ROASTED BEANS OBTAINED WITH SUPERCRITICAL CARBON DIOXIDE

The extraction of coffee oil from roasted beans with supercritical carbon dioxide under different conditions of pressure and temperature was studied to measure the influence of these parameters on the yield and fatty acid content in the oil. For this purpose a 2 factorial experimental design using the response surface methodology was realized. The extraction was performed in a pressure range from 150 to 300 bar and temperatures between 40 and 60 ° C with a constant CO2 flow of 70 g.min -1 and extraction time of 2 hours. The yield was expressed in percentage as g aceite/100 g coffee bean and the fatty acids were analyzed by Gas Chromatography GC-FID and Kovats index. It was found that the pressure, temperature and temperature-pressure interaction had statistically significant effect (P <0.05) on the yield and the optimal extraction conditions were 331,06 bar and 35,86 ° C, where the yield achieved 8.89%. The fatty acids identified were palmitic, linoleic, oleic, stearic, arachidic and linolenic acid, being the palmitic and linoleic the major fatty acids with an average relative percentage of 46.07% and 32.89% respectively. The influence of the temperature and the extraction pressure were statistically significant for linoleic acid, achieving a maximum content of 37.75% in the oil under similar conditions to optimal yield (331,07 bar and 35,07°C). Only the temperature had a statistically significant effect on the content of palmitic acid. The compositional feature of the coffee oil obtained makes it special to be used in the food, pharmaceutical and cosmetic industry.