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Determination of the degree of degradation of frying rapeseed oil using fourier-transform infrared spectroscopy combined with partial least-squares regression.

Chen JY, Zhang H, Ma J, Tuchiya T, Miao Y - Int J Anal Chem (2015)

Bottom Line: One hundred and fifty-six frying oil samples that degraded to different degrees by frying potatoes were scanned by an FTIR spectrometer using attenuated total reflectance (ATR).The precise calibration model based on the second derivative FTIR spectra shows that the coefficients of determination for calibration (R (2)) and standard errors of cross validation (SECV) were 0.99 and 0.16 mg KOH/g and 0.98 and 1.17% for AV and TPC, respectively.The accuracy of the calibration model, tested using the validation set, yielded standard errors of prediction (SEP) of 0.16 mg KOH/g and 1.10% for AV and TPC, respectively.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Bioresource Sciences, Akita Prefectural University, Akita 010-0195, Japan.

ABSTRACT
This rapid method for determining the degree of degradation of frying rapeseed oils uses Fourier-transform infrared (FTIR) spectroscopy combined with partial least-squares (PLS) regression. One hundred and fifty-six frying oil samples that degraded to different degrees by frying potatoes were scanned by an FTIR spectrometer using attenuated total reflectance (ATR). PLS regression with full cross validation was used for the prediction of acid value (AV) and total polar compounds (TPC) based on raw, first, and second derivative FTIR spectra (4000-650 cm(-1)). The precise calibration model based on the second derivative FTIR spectra shows that the coefficients of determination for calibration (R (2)) and standard errors of cross validation (SECV) were 0.99 and 0.16 mg KOH/g and 0.98 and 1.17% for AV and TPC, respectively. The accuracy of the calibration model, tested using the validation set, yielded standard errors of prediction (SEP) of 0.16 mg KOH/g and 1.10% for AV and TPC, respectively. Therefore, the degradation of frying oils can be accurately measured using FTIR spectroscopy combined with PLS regression.

No MeSH data available.


Related in: MedlinePlus

Regression coefficients of the PLS calibration model for TPC based on the second derivative spectra.
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fig6: Regression coefficients of the PLS calibration model for TPC based on the second derivative spectra.

Mentions: Figure 6 shows the regression coefficients of the PLS calibration model based on the second derivative spectra for TPC values. Some notable peaks at wavenumbers 3026, 3008, 2852, 1736, 1149, and 968 cm−1 were easily observed. The negative peak at wavenumber 1736 cm−1 can be assigned to the C=O functional group, which might be related to the absorption of the C=O stretching characteristic frequency associated with ester, aldehyde, and ketone, which increase with the degradation of frying oils [14, 19, 35, 36]. The negative peak at wavenumber 3026 cm−1 can be assigned to the C-H trans functional group and the positive peak at wavenumber 3008 cm−1 can be assigned to the C-H cis functional group, which might be related to unsaturated fatty acids that increase with trans fatty acids and decrease with cis fatty acids in frying oils [14, 19, 35, 36]. The negative peak at wavenumber 968 cm−1 can be assigned to the HC=CH trans bending (out-of-plane) functional group, which might be related to the absorption of trans fatty acids that increase with the degradation of frying oils [14, 19, 35, 36]. Taken together, these results suggest that PLS calibration models with very high precision for prediction of AV and TPC values of frying rapeseed oils could be established. These are based on the absorption of FFA and secondary oxidation products such as carboxylic acid, ester, aldehyde, and ketone groups, which all increase as frying oils deteriorate. The results of the present study have thus shown the utility of using the IR technique to determine the AV and TPC values of frying oils.


Determination of the degree of degradation of frying rapeseed oil using fourier-transform infrared spectroscopy combined with partial least-squares regression.

Chen JY, Zhang H, Ma J, Tuchiya T, Miao Y - Int J Anal Chem (2015)

Regression coefficients of the PLS calibration model for TPC based on the second derivative spectra.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4353439&req=5

fig6: Regression coefficients of the PLS calibration model for TPC based on the second derivative spectra.
Mentions: Figure 6 shows the regression coefficients of the PLS calibration model based on the second derivative spectra for TPC values. Some notable peaks at wavenumbers 3026, 3008, 2852, 1736, 1149, and 968 cm−1 were easily observed. The negative peak at wavenumber 1736 cm−1 can be assigned to the C=O functional group, which might be related to the absorption of the C=O stretching characteristic frequency associated with ester, aldehyde, and ketone, which increase with the degradation of frying oils [14, 19, 35, 36]. The negative peak at wavenumber 3026 cm−1 can be assigned to the C-H trans functional group and the positive peak at wavenumber 3008 cm−1 can be assigned to the C-H cis functional group, which might be related to unsaturated fatty acids that increase with trans fatty acids and decrease with cis fatty acids in frying oils [14, 19, 35, 36]. The negative peak at wavenumber 968 cm−1 can be assigned to the HC=CH trans bending (out-of-plane) functional group, which might be related to the absorption of trans fatty acids that increase with the degradation of frying oils [14, 19, 35, 36]. Taken together, these results suggest that PLS calibration models with very high precision for prediction of AV and TPC values of frying rapeseed oils could be established. These are based on the absorption of FFA and secondary oxidation products such as carboxylic acid, ester, aldehyde, and ketone groups, which all increase as frying oils deteriorate. The results of the present study have thus shown the utility of using the IR technique to determine the AV and TPC values of frying oils.

Bottom Line: One hundred and fifty-six frying oil samples that degraded to different degrees by frying potatoes were scanned by an FTIR spectrometer using attenuated total reflectance (ATR).The precise calibration model based on the second derivative FTIR spectra shows that the coefficients of determination for calibration (R (2)) and standard errors of cross validation (SECV) were 0.99 and 0.16 mg KOH/g and 0.98 and 1.17% for AV and TPC, respectively.The accuracy of the calibration model, tested using the validation set, yielded standard errors of prediction (SEP) of 0.16 mg KOH/g and 1.10% for AV and TPC, respectively.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Bioresource Sciences, Akita Prefectural University, Akita 010-0195, Japan.

ABSTRACT
This rapid method for determining the degree of degradation of frying rapeseed oils uses Fourier-transform infrared (FTIR) spectroscopy combined with partial least-squares (PLS) regression. One hundred and fifty-six frying oil samples that degraded to different degrees by frying potatoes were scanned by an FTIR spectrometer using attenuated total reflectance (ATR). PLS regression with full cross validation was used for the prediction of acid value (AV) and total polar compounds (TPC) based on raw, first, and second derivative FTIR spectra (4000-650 cm(-1)). The precise calibration model based on the second derivative FTIR spectra shows that the coefficients of determination for calibration (R (2)) and standard errors of cross validation (SECV) were 0.99 and 0.16 mg KOH/g and 0.98 and 1.17% for AV and TPC, respectively. The accuracy of the calibration model, tested using the validation set, yielded standard errors of prediction (SEP) of 0.16 mg KOH/g and 1.10% for AV and TPC, respectively. Therefore, the degradation of frying oils can be accurately measured using FTIR spectroscopy combined with PLS regression.

No MeSH data available.


Related in: MedlinePlus