Enhancement of Caffeine Concentration in Todolo Coffee Callus Cultures with L-Methionine and UV-Vis Spectrophotometry.

<b>Background and Objective:</b> Todolo coffee (<i>Coffea arabica</i> L. var. typica) is the oldest commercially grown coffee in the Toraja region of South Sulawesi and is currently at risk of extinction. This study aims to induce callus from leaf explants of Todolo arabica coffee and improve the levels of caffeine compounds in Todolo coffee with the additional precursor L-methionine as elicitor. <b>Materials and Methods:</b> This research was conducted at the Tissue Culture Laboratory, Faculty of Mathematics and Natural Sciences, Hasanuddin University. This experimental study used a Complete Randomized Design (CRD) approach. The five stages involved callus induction, elicitation with L-methionine precursor, caffeine extraction, qualitative testing using the Parry Method and quantitative analysis via UV-Vis spectrophotometry. Tools and materials were sterilized using autoclaving and media preparation followed standard procedures with varying L-methionine concentrations. Callus induction from sterilized leaf explants was done under aseptic conditions, followed by L-methionine treatment and caffeine content extraction. Caffeine was analyzed using UV-Vis spectrophotometry at 272 nm and statistical analysis was conducted using ANOVA and DMRT at a 5% significance level. <b>Results:</b> The friable callus structure has a shiny and wavy appearance and is more easily detached, which is highly correlated with the speed of callus growth. The callus on the treatment medium is slightly yellowish-white to somewhat brownish, indicating the production of secondary metabolites. The best concentration of L-methionine treatment was 25 mg/L with a percentage of caffeine content of 0.0078%. <b>Conclusion:</b> Results concluded that the addition of L-methionine has a significant effect on the percentage of caffeine production.