Detection of Sludge Contamination in Crude Palm Oil Using Dielectric Spectroscopy

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Hamdan, Khairunnisa
Abd Aziz, Samsuzana
Yahya, Azmi
Rokhani, Fakhrul
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Steward, Brian
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Agricultural and Biosystems Engineering

Since 1905, the Department of Agricultural Engineering, now the Department of Agricultural and Biosystems Engineering (ABE), has been a leader in providing engineering solutions to agricultural problems in the United States and the world. The department’s original mission was to mechanize agriculture. That mission has evolved to encompass a global view of the entire food production system–the wise management of natural resources in the production, processing, storage, handling, and use of food fiber and other biological products.

In 1905 Agricultural Engineering was recognized as a subdivision of the Department of Agronomy, and in 1907 it was recognized as a unique department. It was renamed the Department of Agricultural and Biosystems Engineering in 1990. The department merged with the Department of Industrial Education and Technology in 2004.

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  • Department of Agricultural Engineering (1907–1990)

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Degradation and deterioration of crude palm oil (CPO) is a major concern in the palm oil industry because it could affect the quality of palm oil products. The development of rapid and non-destructive measuring techniques is needed to enhance the efficiency of palm oil quality monitoring. This study used dielectric spectroscopy to detect possible sludge contamination in CPO. Dielectric properties of CPO were measured at different temperatures and sludge contamination levels using a liquid dielectric test fixture that was connected to an impedance analyzer with frequencies ranging from 3 to 30 MHz. The variations in dielectric properties were analyzed using ANOVA and Duncan’s multiple range test. Principal component regression (PCR) and partial least squares (PLS) analysis were used for model development to predict sludge contamination. The results showed that there was a significant difference in dielectric constant as the temperature increased from 28°C to 55°C (p < 0.0001). The dielectric constant also increased from 3.01 to 63.53 with increasing contamination levels. Generally, there were significant differences between the dielectric constants of pure and contaminated CPO (p < 0.0001). The PCR and PLS calibration models showed good prediction ability of sludge contamination at different temperature levels. The classification of sludge contamination yielded very strong correlation, with r2 values ranging from 0.91 to 0.98. The best result was obtained at 28°C with the lowest value of standard error cross-validation (SECV) of 1.04%. The results showed that dielectric spectroscopy has strong potential for CPO quality monitoring.


This article is from Transactions of the ASABE 58 (2015): 227–232, doi:10.13031/trans.58.10656. Posted with permission.

Thu Jan 01 00:00:00 UTC 2015