Several hundred volatile compounds have been identified in roasted peanuts. The raw seed has a green, bean-like flavor (mainly from green-leaf hexanal and the pyrazine that characterizes peas). The roasted aroma is a composite of several sulfur compounds, a number of generically “nutty” pyrazines, and others, some of which have fruity, flowery, fried, and smoky characters. During storage and staling, the nutty pyrazines disappear and painty, cardboard notes increase.
From the book On Food and Cooking (2nd edition) by Harold McGee. © 2004 Harold McGee.
By permission of Scribner, a division of Simon & Schuster, Inc.