Use of a portable electronic nose to detect off-flavor peanuts

Abstract

The feasibility of using a commercial, portable electronic nose to detect off-flavor in peanuts was evaluated in two phases. In phase one, the sensitivity of the electronic nose to headspace humidity was tested by exposing the 32 polymer composite chemiresistors of the electronic nose to LiCl salt solutions at seven different relative humidity environments. All 32 sensors of the electronic nose responded to water vapor at low relative humidity levels. Sensors 1, 2, 3, 4, 7, 8, 9, 12, 14, 16, 17, 21, 22, 23, 24, 25, 26, 27, 29, 31, and 32 did not exhibit a significant response to high humidity environments. In phase two, acetaldehyde and ethanol off-flavor indicating volatiles were generated by exposing peanut pods of the same moisture content to high temperatures (C⁰) . Volatile levels were confirmed by gas chromatography. The Cyranose 320 was able to determine the presence of different levels of off-flavor indicating volatiles in Florunner peanuts. Sensors 6, 27, and 28 showed the most significant response to high temperature off-volatiles after adjusting for humidity using a multivariate analysis of variance (MANOVA). It can be concluded from phase one and phase two results that sensors 6 and 28 can respond to high temperature off-volatiles if the relative humidity conditions are kept constant throughout the data collection process. Sensor 27 can respond to peanut off-volatiles and is not affected by relative humidity if it is above 60%.