Antioxidant Activity of Fermented Inferior Jember Robusta Coffee Beans Using Saccharomyces cerevisiae as a Starter in the Semi-carbonic Maceration Technique

Abstract

Aims: To determine the antioxidant activity, total phenol compounds, total flavonoid compounds, and total tannin compounds of raw non fermented robusta coffee beans, the semi-carbonic maceration technique was employed at various concentrations of Saccharomyces cerevisiae starter and fermentation times. Study Design:  This study used a completely randomized design (CRD) consisting of 2 factors. The first factor was the starter concentration, and the second factor was the fermentation time. Place and Duration of Study: This research was conducted in the laboratory of Faculty of Agricultural Technology from September 2022 to April 2023. Methodology: This research used a Completely Randomized Design (CRD) with two factors. The first factor was the concentration of yeast S. cerevisiae (A), which consisted of A1 at 20% and A2 at 30%. The second factor was the fermentation duration (B), which consisted of B1 for 24 hours, B2 for 48 hours, and B3 for 72 hours. Based on these two factors, a total of 6 treatment combinations were obtained, and each treatment combination was replicated 3 times. The testing includes the assessment of antioxidant activity, total phenol compounds, total flavonoid compounds, and total tannin. The data obtained will be analyzed using Analysis of Variance (ANOVA) through statistical software (SPSS) at a significance level of 5%. If significant differences are found in the results, the analysis will be followed by the Duncan New Multiple Range Test (DNMRT) to determine specific group differences and identify which treatments significantly differ from one another. Results: The research results indicate that the highest antioxidant activity, phenolic compounds, flavonoids, and tannins in fermented inferior Jember robusta coffee beans using Saccharomyces cerevisiae were obtained from sample A2B2, which resulted from a starter concentration 30% and a fermentation time of 48 hours. Meanwhile, the lowest values for all parameters were found in sample A1B1, which resulted from a starter concentration of 20% and fermented time of 24 hours. Conclusion: Saccharomyces cerevisae can enhance antioxidants in unfermented inferior robusta coffee beans from Jember.