Effect of Microwave Use on Kawa Daun Production: Production, Composition, and Antioxidant Properties

Kawa daun tea is a drink made of dried coffee leaves from Western Sumatra, offering refreshing benefits for the body. The use of a microwave in the drying process proves to be an effective method due to its significantly high efficiency. Therefore, this study aimed to investigate the impact of varying drying time using microwave on the characteristics of coffee leaves, kawa daun tea, and drinking water, as well as to determine effect of microwave treatment. This study uses a complete random design with ANOVA (Analysis of Variance) and followed by a DNMRT (Duncan’s News Multiple Range Test). The results showed that the difference in drying times significantly affected properties of coffee tea leaves, specifically on the total water-soluble substance test. However,there was no substantial impact on the yield, water level, polyphenols level, caffeine level, and antioxidant activity. The length was also affected by polyphenols level, total soluble solidity, and water solubility antioxidant activity, but did not impact caffeine content test. The maximum time for optimal drying coffee leaves was two minutes with a yield of 35.99% hydration, 4.33% water level, 48.56 mgGAE/g total polyphenols level, 0.56% caffeine level, 63.43% oxidative activity, and 4.61% total water-soluble material. In the chemical analysis of drinking water, the results obtained were total polyphenol content of 28.1 mg GAE/g, caffeine content of 0.45%, total dissolved solids of 1.87%, and antioxidant activity of 88.79%. Thus, it is also concluded that there is no negative effect of drying coffee leaves with a microwave. Key words: Antioxidant; caffeine; robusta coffee leaves; microwave drying; polyphenols.