Effectiveness of tofu waste for decreasing chlorogenic acid of robusta coffee (coffee robusta Lindl.Ex De Will)

This study aimed to determine type and concentration of tofu waste which decreasing chlorogenic acid content of robusta green coffee effectively. Decaffeination of coffee could be done using protein-rich wastes, which could potentially act as an organic solvent containing protease. One of them known to be generated in large amount, but has not handled correctly is tofu waste. Generally, tofu wastes divided into two forms such as solid waste and liquid one. The expansion of tofu industry caused growing amount of produced waste. Method of this research consist of preparing coffee sample, preparing tofu waste and measurment of chlorogenic acid levels by spectrophotometry. The results showed that chlorogenic acid content decreased after immersion in the tofu waste. Tofu waste has a proteolytic activity originating from microorganisms in it producing protease. Immersion of robusta coffee beans in tofu waste could cause chlorogenic acid to transform into a compound having lower molecular weight making it easily get out of the coffee beans. As conclusion, robusta coffee beans immersed in liquid tofu waste in concentration of 90% could produce the most excellent quality in terms of chlorogenic acid content. (paper)