Electrical properties and organoleptic test on coffee powder mixed robusta coffee and soybean

Abstract

East Java is categorized as one of the provinces in Java Island that has a high coffee production in Indonesia. One of the coffee producing areas in East Java is Jember Regency which is dominated by Robusta coffee. Coffee product on the market in general have been modified into non-pure coffee products. One of the ingredients that is often used as a blend on coffee powder products is soybean. It is intended to add flavor to the coffee produced at the same time to reduce production costs. To know the characteristics of mixed coffee powder, it is necessary to take measurements of electrical properties, i.e dielectric constants and electrical conductivity. In addition, to know the consumer's taste for mixed coffee powder, it is also necessary to conduct organoleptic tests with flavor and aroma parameters. Robusta coffee sample variations to be analyzed include pure Robusta coffee and Robusta coffee-soybean mixture, which is processed using three variations of roasting temperature i.e low roasting (190oC), high roasting (215oC) and dark roasting (240oC). The results of this measurement showed that the value of dielectric constants and electrical conductivity decreased along with the addition of the mass fraction of the soybean mixture used. This also occurs in each variation in the temperature of the roaster. Organoleptic test assessment of the taste of pure Robusta coffee and Robusta coffee-soybean mixture that obtained a very good category is pure Robusta coffee with a roasting temperature of 215oC. Others Robusta coffee-soybean mixture included in good taste category. Organoleptic test results of aroma are known that for pure Robusta coffee with a variation in roasting temperature of 195oC, 215oC and 240oC, Robusta coffee with a mixture of 40% soybean at a roasting temperature 215oC has a very fragrant category.