There is no known nutritional value to this spice. The pungent principles of pepper are contained in the oleoresin and include the alkaloids piperine, chavicine, and piperidine. The taste is hot and biting. In addition to its principal use for increasing the flavor of bland meals, pepper in the past covered up the rancid odors and tastes of spoiled foods. Today pepper comes in several forms.
Green peppercorns are the unripened fruits which are pickled or preserved in brine.
Once a jar is opened, the green peppercorns will remain in good condition for about two weeks if kept refrigerated. Black peppercorns are the most common form. The fruits are harvested in their unripened or green stage, boiled for about 10 minutes, and then are allowed to dry until they become wrinkled and black. Although they keep for up to a year when sealed in glass jars, black peppercorns quickly lose their aroma, taste, and pungency after they are ground. For that reason, cooks are advised not to use pre-ground powder, but rather to keep a peppermill for custom grinding.