Abstract SCHIRACK, ANDRIANA VAIS. The Effect of Microwave ...

oxidative rancid flavor (Sanders et al., 1993; Warner et al., 1996). The effect of
blanching on lipid oxidation is not yet known, as some studies have shown an
increase in lipid oxidation after blanching (Ory et al., 1992), while a study by Sanders
et al. (1999) showed no practical detrimental effects of blanching on oxidative
stability.
The quality and flavor of peanuts were evaluated first using a method called
the Critical Laboratory Evaluation of Roasted Peanuts, or CLER (Holaday, 1971).
Later, sensory lexicons for peanuts and peanut products were constructed by
Oupadissakoon and Young (1984) and Syarief et al. (1985). A standardized lexicon
subsequently was developed to address deficiencies in earlier models such as lack
of differentiation in oxidized off-flavors and lack of sweet/caramel descriptors
(Johnsen et al., 1988). In this lexicon, a ten point scale is used to rate intensity of
flavor, using commercially available products as references. This terminology
subsequently was modified and improved, including the addition of a "fruity"
descriptor associated with high temperature curing (Sanders et al., 1989).
Using descriptive sensory analysis, a processing-related off-flavor has been
noted in peanuts undergoing microwave blanching. The off-flavor has been
described as having “stale” and “sour” notes (Katz, 2002). The cause of this off-
flavor is not known. The objective of this study was to characterize the impact of
different microwave blanching parameters on the sensory attributes of roasted
peanuts. The effects of the moisture content of the peanuts and internal temperature
profiles were studied in relation to sensory characteristics determined by a
descriptive panel.
122