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ARS Home » Southeast Area » Raleigh, North Carolina » Market Quality and Handling Research » Research » Publications at this Location » Publication #197821
Title: IMPACT OF MICROWAVE BLANCHING ON THE FLAVOR OF ROASTED PEANUTS

Author
item SCHIRACK, ANDRIANA - NC STATE UNIVERSITY
item DRAKE, MARYANNE - NC STATE UNIVERSITY
item Sanders, Timothy
item SANDEEP, K - NC STATE UNIVERSITY

Submitted to: Journal of Sensory Studies
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/28/2006
Publication Date: 8/7/2006
Citation: Schirack, A.V., Drake, M., Sanders, T.H., Sandeep, K.P. 2006. Impact of microwave blanching on the flavor of roasted peanuts. Journal of Sensory Studies. 21 (4) 428-440.

Interpretive Summary: Peanuts are blanched to remove the red seed coat surrounding the seed for particular applications such as peanut butter and to better examine the seed for damage. The current process of heating peanuts is done with gas fired roasters and requires approximately an hour. Microwave blanching is attractive alternative to traditional techniques of blanching, due to energy and time savings. In any process the potential of flavor changes is possible and at high microwave temperatures an off flavor can develop in peanuts. This study examined the effect of processing factors during microwave blanching on the moisture content and sensory characteristics of peanuts. A proper protocol was determined but peanuts reaching the highest internal temperatures and greatest moisture losses during blanching exhibited the most total offnote flavor. For maximum quality, microwave blanching for 8 minutes without air circulation is recommended.

Technical Abstract: Microwave blanching of peanuts has been proposed as an attractive alternative to traditional techniques of blanching, due to energy and time savings. However, the periodic occurrence of a processing-related off-flavor has been reported. This study examined the effect of processing factors during microwave blanching on the moisture content and sensory characteristics of the peanuts. Peanuts reached a range of internal temperatures during microwave blanching treatments between 4 and 11 minutes. A total offnote attribute was introduced to the peanut lexicon and was successfully used to differentiate the effects of microwave treatments. The microwave-associated off-flavor was related (but not identical) to cardboardy/stale flavor, and was inversely related to the positive flavor attributes roasted peanutty, sweet aromatic, and sweet taste. Peanuts reaching the highest internal temperatures and greatest moisture losses during blanching exhibited the most total offnote flavor. For maximum quality, microwave blanching for 8 minutes without air circulation is recommended.