Black peppercorns (Piper nigrum L.) were heated at temperatures between 100°C and 150°C for 15 or 30 min and in a microwave oven at various settings to simulate dry roasting of the spice. Analysis showed that under these conditions there was little change in the amount of volatile oil, oleoresin or piperine in the spice. However, sensory evaluation indicated an improvement in the aroma of the heated peppercorns. Essential oil analysis by GC and GC-MS showed some changes in the composition of the volatile oils after heating possibly due to loss of a few very volatile components and/or due to release of glycosidically bound terpenoids. A few compounds have been tentatively identified, for the first time, to occur in pepper oil.