The Effect of Initial Temperature and Time of Infusion on Antibacterial and Antioxidant Activities in the Herbal Drink Extract of Robusta Coffee Leaves

Abstract

The aim of this study was to find out initial infusion temperature and infusion time effects on of antibacterial  and antioxidant activities the Robusta Coffee leaves herbal drink extract. This study also determined the best  initial infusion temperature and infusion time that can produce Robusta Coffee leaves herbal drink extract  with the best antibacterial and antioxidant activities. The study used factorial completely randomized design.  The first factor is infusion temperature, consisting of 70±2°C, 80±2°C, and 90±2°C. The second factor is  infusion time which consists of 5, 10, and 15 minutes. The data was analyzed by analysis of variance (ANOVA)  and continued with Tukey test. The results showed that the treatment of initial infusion temperature, infusion  time, and interaction between the two treatments had a very significant effect on antibacterial activity Abritrary Unit (AU) against Salmonella typhimurium and antioxidant activity Inhibitory Concentration 50  (IC50). The treatment of infusion time had a significant effect on antibacterial activity AU against Escherichia  coli, but the initial infusion temperature and interaction between the two treatments had a very significant  effect on it. The best treatment to infuse herbal drink of Robusta Coffee leaves as a source of antibacterial and  antioxidant is using initial infusion temperature of 90±2°C and infusion time of 5 minutes with antibacterial  activity AU against Escherichia coli of 1.248,34 ± 132,58 mm2/mL, antibacterial activity AU against  Salmonella typhimurium of 1.473,37 ± 79,57 mm2/mL, and antioxidant activity IC50 of 185,01 ± 1,66 ppm.