Location: Peanut Research
Title: Estimation of moisture and oil content of in-shell nuts with a capacitance sensor using discrete wavelet analysis Authors
Submitted to: Proceedings of SPIE
Publication Type: Proceedings
Publication Acceptance Date: February 14, 2009
Publication Date: February 14, 2009
Citation: Kandala, C., Sundaram, J., Govindarajan, K.N., Butts, C.L., Jeyam, S. 2009. Estimation of moisture and oil content of in-shell nuts with a capacitance sensor using discrete wavelet analysis . Proceedings of SPIE. Interpretive Summary: None required.
Technical Abstract: . Moisture and oil contents are important quality factors often measured and monitored in the processing and storage of food products such as corn and peanuts. For estimating these parameters for peanuts nondestructively a parallel-plate capacitance sensor was used in conjunction with an impedance analyzer. Impedance, phase angle and dissipation factor were measured for the parallel-plate system, holding the in-shell peanut samples between its plates, at frequencies ranging between 1MHz and 30 MHz in intervals of 0.5 MHz. The acquired signals were analyzed with discrete wavelet analysis. The signals were decomposed to 6 levels using Daubechies mother wavelet. The decomposition coefficients of the sixth level were passed onto a stepwise variable selection routine to select significant variables. A linear regression was developed using only the significant variables to predict the moisture and oil content of peanut pods (in-shell peanuts) from the impedance measurements. The wavelet analysis yielded similar R2 values with fewer variables as compared to multiple linear and partial least squares regressions. The estimated values were found to be in good agreement with the standard values for the samples tested. Ability to estimate the moisture and oil contents in peanuts without shelling them will be of considerable help to the peanut industry.