Trigonelline in coffee. II. Content of green, roasted and instant coffee

The results of several determinations of trigonelline in green, roasted and instant coffees are reported. The values in normal coffee species and degrees of roast are in agreement with most literature values. In Coffea dewevrei var. excelsa and C. stenophylla lower values were found than reported in the only other publication. The differences from steamed samples were minimal. Fast roasting may result in higher values with the same organic roasting loss, but this was not observed in commercial blends. During industrial extraction of roasted coffee, trigonelline is not completely extracted. The percentage depends on the extraction yield.