Biblioteca do Café

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Resultados da Pesquisa

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    Effect of Microwave Use on Kawa Daun Production: Production, Composition, and Antioxidant Properties
    (Editora UFLA, 2025-06-03) Arief, Rastra Gemi Nastiti; Malrianti, Yefsi; Kasim, Anwar; Neswati; Sujatmiko
    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.
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    Antioxidant Activity and Phytochemicals of Freeze-dried and Spray-dried Soluble Coffee Brews
    (Editora UFLA, 2025-05-19) Susilawati, I Dewa Ayu; Muzeka, Fredi
    This study analyzed the antioxidant activity and the concentration of several phytochemicals i.e. polyphenols, caffeine, glutathione (GSH), and protein, of freeze-dried and spray-dried soluble coffee brews. Six types of coffee samples were analyzed i.e., 1) Spray-Dried Robusta instant coffee (SDR), 2) Freeze-Dried Robusta instant coffee (FDR), 3) Regular Robusta coffee powder (RR), 4) Spray-Dried Arabica instant coffee (SDA), 5) Freeze-Dried Arabica instant coffee (FDA), and 6) Regular Arabica coffee powder (RA). Antioxidant activity was determined using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging assay. Polyphenols, caffeine, glutathione, and protein were measured spectrophotometrically. Results showed that freeze-dried instant coffee (both robusta and arabica) in a concentration of 500 ppm demonstrated DPPH radical scavenger activity >80% and significantly higher (p<0.05) compared to spray-dried soluble coffee and regular coffee brews. This level was maintained in concentrations of 750 ppm, 1000 ppm, and 1500 ppm. The higher antioxidant activity of freeze-dried coffee brew was in line with the higher concentration of polyphenols, caffeine, GSH, and protein. In conclusion, freeze-dried instant coffee demonstrated more sensitive antioxidant activity, probably due to its more abundant polyphenols, caffeine, GSH, and protein.