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ELECTRONIC NOSE CHEMICAL SENSOR FEASIBILITY STUDY FOR THE DIFFERENTIATION OF APPLE CULTIVARS

2005; Volume: 48; Issue: 5 Linguagem: Inglês

10.13031/2013.19992

2151-0059

W. N. Marrazzo, Paul Heinemann, R.M. Crassweller, Élisabeth Leblanc,

Fermentation and Sensory Analysis

The ability to analytically differentiate and match intact apple (Malus domestica, Borkh) fruit and fruit juiceextracts from different apple cultivars is of interest to the food industry. This study tested the feasibility of detecting thedifference among volatile gases evolved from intact McIntosh (Buhr), Delicious, and Gala apples and their extractedjuice using a prototype 32-array polymeric detector chemical sensor. All data were first processed to obtain principalcomponents. PCA analysis clearly separated whole McIntosh, Gala, and Delicious samples from juiced on day 1. PCAanalysis of day 2 samples showed clustering of whole vs. juiced for all three cultivars, although there was some overlapbetween the clusters. A soft independent modeling of class analogy (SIMCA) class discrimination of the sensor principalcomponent data sets was then performed to determine the degree of difference. SIMCA analysis of the same samples showeda pronounced difference (SIMCA value >3.00) for only the McIntosh samples. SIMCA values between 2.00 and 3.00 werefound for the other two cultivars on day 1. For day 2 samples, no SIMCA values greater than 2.00 were found for any cultivarwhole vs. juiced. PCA analysis showed clear separation between cultivars for day 1 whole samples. SIMCA analysis showedthat there was a difference between Delicious and McIntosh and between Delicious and Gala. Neither PCA nor SIMCAshowed good separation between day 2 whole cultivars, nor between juiced cultivars on either day. As a reference, the samesample headspace volatile gases were analyzed with a mass spectrometer. A hierarchical cluster analysis (HCA) of theprincipal components from the mass spectrometer data sets revealed five clusters that discriminated differences among intactapple and apple juice samples but did not discriminate between samples from different apple cultivars.