Coffee is an economically important plant and has been a famous non-alcoholic beverage globally. This study aimed to investigate the coffee quality of Saccharomyces boulardii (S. boulardii) inoculated to different post-harvest processed coffee beans (dry method and semi-dry method). The result showed that the pH value decreased along with the processing period. Moisture content had the final content below 12%. Water activity decreased along with the processing period, reaching around 0.40 at the end of processing. Color parameters resulted in an increased browning index after roasting. The organic acid showed an increasing trend in each acid after roasting, especially for glycolic acid and citric acid. The phenolic acid degraded after roasting each sample. The caffeine content increased after roasting each sample. The D and S groups had higher total sugar content than the yeast-inoculated group before roasting, while roasting the S group had the highest total sugar content. Total phenolic content resulted in the highest content in group D while roasted in group SY. For antioxidant capacity, the SY had the lowest IC₅₀ value (2.85 g/ml) in unroasted beans. For the sensory evaluation, each of the samples presented a different flavor after roasting.

Novelty impact statement

The coffee quality including physicochemical, chemical analysis, and sensory evaluation of Saccharomyces boulardii inoculated to different post-harvest processed coffee beans (dry method and semi-dry method) are determined. The result of the physicochemical analysis did not show significant changes; however, for chemical analysis, there were significant changes in semi-dry processed beans.