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ARS Home » Southeast Area » Raleigh, North Carolina » Market Quality and Handling Research » Research » Publications at this Location » Publication #94252
Title: SENSORY ATTRIBUTE VARIATION IN LOW TEMPERATURE-STORED ROASTED PEANUT PASTE

Author
item Pattee, Harold
item GIESBRECHT, FRANCIS - NC STATE UNIVERSITY
item ISLEIB, THOMAS - NC STATE UNIVERSITY

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: Sensory analysis studies with large numbers of samples for analysis may require extended in-storage times before actual analysis of a sample can be performed. Little is known about the intensity changes that might occur in the sensory characteristics during these extended storage times at below freezing temperatures. The combination of three separate studies lasting up pto 13 months have permitted an evaluation of stability and slow-rate sensory changes of selected sensory characteristics. Staleness increased indicating that fat oxidation was taking place even under -23 C storage conditions. Rancidness, which is a more intense form of staleness, did not become identifiable until staleness had reached a level of three flavor intensity units. Fruityness, a very undesirable characteristic, increased unexpectedly and reasons for its increase are not known. Because both fruityness and staleness cause a loss of perception of the roasted peanut characteristic intensity, a decrease in the intensity of roasted peanut could be anticipated. However, storage at -23 C did seem to stabilize the natural loss of roasted peanut. We have shown, for the first time, that fruityness, staleness, and natural loss of roasted peanut are three separate and identifiable effects on roasted peanut intensity. These findings may help researchers develop protocols by which the intensity of the roasted peanut characteristic can be maintained until the peanut butter is consumed.

Technical Abstract: Descriptive sensory analysis protocols limit the number of samples evaluated in a given session. For roasted peanut paste it is four. In peanut genetic studies a minimum of two replications at two locations for each entry are needed to give a reasonable expectation of finding significant differences. Thus with studies near 60 entries sensory panel evaluation time can be lengthy. For these sensory studies it is standard t store samples between -10 C and -23 C to prevent or retard sensory changes over the analysis period. Extended studies of up to 13 months have permitted the evaluation of stability and slow-rate sensory changes of selected attributes. Sensory attribute sweet was relatively stable while bitter and tongue burn were shown to increase slightly over storage time. The attribute stale showed an increase indicating that lipid oxidation was taking place even under -23 C storage conditions. The painty intensity is related to stale and generally did not begin to increase until stale had reached three flavor intensity units. An observed increase in fruity attribute was unexpected and reasons for its increase are not known. With increase in both fruity and stale, a decrease in roasted peanut intensity could be anticipated. However, storage at -23 C seems to stabilize the roasted peanut lability. We have shown, for the first time, that fruity, stale, and lability of roasted peanut are three separate and identifiable effects on roasted peanut intensity.