Optimization of Roasting Technology and Measurement of Total Sugar Contents in Yunnan Arabica Coffee

Yunnan Arabica coffee bean was baked by electric heating as the raw material. The main factors initial temperature, baking time, amount of baking and throttle opening degree were used to evaluate the quality of coffee. The single factor and orthogonal experiments estimated the expansion rate, weightlessness rate and sensory evaluation. And the experiment adopted comprehensive weighted scoring method for data analysis. Results showed that the optimum conditions process of Yunnan Arabica coffee were as follows:Initial temperature 240℃, baking weight of 160 g for 13 min, throttle opening degree 21 mm. The coffee beans obtained at this time were shallow deep roasted coffee beans, and the weight loss rate was 21.92%, the puffing rate was 91.11%, the sensory score was 36 points, and the overall score was 0.9144 points. According to the chromaticity value and the size of the comprehensive weighted score. The better process conditions of light roasting was the initial temperature at 240℃, baking weight of 180 g for 10 min, throttle opening degree of 14 mm. The better process conditions of medium roasting was the initial temperature at 240℃, baking weight of 220 g for 12 min, throttle opening degree of 0 mm. The better process conditions of dark roasting was the initial temperature at 250℃, baking weight of 160 g for 12 min, throttle opening degree of 7 mm. The effects of different baking degrees on total sugar contents were significant (p<0.05), and the total sugar contents gradually decreased with the deepening of baking degree.