Abstract
Roasting Arachis hypogaea L. seeds for snack foods requires control of roasting temperature and time to optimize eating quality. Extra large virginia and jumbo runner peanut seeds were oil roasted at different thermal input levels to examine relationships between roast color and other analytical measurements related to roast quality. A laboratory roaster and commercial lots of peanut seeds were used to simulate the commercial process. The concentration of volatiles such as pyrazines increased in roasted seeds with increased thermal energy. Descriptive sensory analyses on these same roasted seed samples showed that optimal balance of important flavor characteristics such as roasted peanut, dark roast, and sweet had distinct roast temperature and time requirements. Excessive heat increased negative flavor components such as bitter. Conventional tests for roaster control such as roast color (CIELAB L*) or seed moisture content changed only slightly during the period when optimal roast quality was achieved. For a given seed lot, optimal roast required both appropriate roast color and tests of roasted peanut flavor. Roasted peanut products dependent on the enhanced stability of the high oleic acid trait required measurements of either oxidative stability, or the fatty acid profile, to ensure the desired product shelf life. Analytical methods such as those discussed here allow the commercial roaster to reach an optimal roast quality while using a diverse raw material supply.