A. Rygula and P. Miskowiec
294
The analysis of lycopene and β-carotene in tomatoes fruits and their products
using Ft-Raman, AtR IR and NIR spectroscopy gives similar results [10]. the
best prediction was achieved for PLS model based on the AtR IR spectroscopy
( R
2
= 0.98 and − 0.97, SECV = 33.20 and 0.16 for lycopene and β-carotene, respectively), whilst the worst prediction was shown for NIR spectroscopy ( R
2
= 0.85 and
0.80, SECv = 91.19 and 0.41, respectively) [8]. It may be caused by a high water
content in all tomato samples which dominate in the NIR spectra. It is important to
notice, that the prediction quality for AtR IR spectroscopy in the 650–1,800 cm
−1
is better than for FtRS, even when the wavenumber range was limited to marker
carotenoid band. however, Ft-Raman (1,064 nm) spectroscopy enabled to discriminate lycopene (1510 cm
−1
) and β-carotene (1,520 cm
−1
) signals what is impossible
using laser excitation in the visible range [84].
The β-carotene and parietin (antraquinon) were analyzed in Antarctic lichens using Ft-RS combined with cluster analysis (CA) and principal component analysis
(PCA) [85]. the aim of that study was to obtain relative quantitative information
about changes of pigment concentration in samples.
the interesting example of a carotenoid detection in the industrial approach is
the determination of the total carotenoid concentration in dried pastas [86]. the
authors compared the different techniques like hPLC, spectrophotometry, colorimetric and photoacoustic spectroscopy (PAS) with the resonance Raman technique.
the results obtained for RS was satisfactory however, the PAS was found as the
most favourable method mainly because of better sensitivity and repeatability of
measurements.
the RS could be potentially applied to the analysis of carotenoids in fruit and
vegetable juices [84]. the analysis of grape, orange, tomato, carrot and vegetable mix products were carried out using 488 nm laser and the height of band at
1,525 cm
−1
was quantified for data processing. It is worth notice that better correlation was obtained for diluted samples ( R = 0.98, P = 0.003) than for undiluted
( R = 0.94, P = 0.01).
the potential of mid-infrared spectroscopy for the chemical study of carotenoids, have been established a few decades ago [87]. however, the recent research
has depicted the capability of this technique for the simultaneous quantitative and
qualitative determination of carotenoids i.e. lycopene and β-carotene in fruits like
tomatoes [43, 88]. Fig. 10.11 depicts an example of the correlation between lycopene content in different tomato varieties measured by mid-IR and hPLC methods.
the authors analyzed the 950–980 cm
−1
infrared region where C = C trans double
bonds absorb and used partial least square regression (PLSR) to produce calibration
models that correlate lycopene or β-carotene concentration in standards (as determined by uv-vis spectroscopy) with their infrared spectra. the achieved correlation factors were satisfying ( R
2
= 0.95), thus the PLSR calibration models were then
used to predict the lycopene concentration in commercial and experimental tomato
varieties using their infrared spectra.
those research were coherent with earlier studies [10] showing the application
of three different types of spectroscopies (Ft-Raman, AtR IR, and NIR Spectroscopy) in carotenoids analysis. As a results authors got the best correlation with hPLC
294
The analysis of lycopene and β-carotene in tomatoes fruits and their products
using Ft-Raman, AtR IR and NIR spectroscopy gives similar results [10]. the
best prediction was achieved for PLS model based on the AtR IR spectroscopy
( R
2
= 0.98 and − 0.97, SECV = 33.20 and 0.16 for lycopene and β-carotene, respectively), whilst the worst prediction was shown for NIR spectroscopy ( R
2
= 0.85 and
0.80, SECv = 91.19 and 0.41, respectively) [8]. It may be caused by a high water
content in all tomato samples which dominate in the NIR spectra. It is important to
notice, that the prediction quality for AtR IR spectroscopy in the 650–1,800 cm
−1
is better than for FtRS, even when the wavenumber range was limited to marker
carotenoid band. however, Ft-Raman (1,064 nm) spectroscopy enabled to discriminate lycopene (1510 cm
−1
) and β-carotene (1,520 cm
−1
) signals what is impossible
using laser excitation in the visible range [84].
The β-carotene and parietin (antraquinon) were analyzed in Antarctic lichens using Ft-RS combined with cluster analysis (CA) and principal component analysis
(PCA) [85]. the aim of that study was to obtain relative quantitative information
about changes of pigment concentration in samples.
the interesting example of a carotenoid detection in the industrial approach is
the determination of the total carotenoid concentration in dried pastas [86]. the
authors compared the different techniques like hPLC, spectrophotometry, colorimetric and photoacoustic spectroscopy (PAS) with the resonance Raman technique.
the results obtained for RS was satisfactory however, the PAS was found as the
most favourable method mainly because of better sensitivity and repeatability of
measurements.
the RS could be potentially applied to the analysis of carotenoids in fruit and
vegetable juices [84]. the analysis of grape, orange, tomato, carrot and vegetable mix products were carried out using 488 nm laser and the height of band at
1,525 cm
−1
was quantified for data processing. It is worth notice that better correlation was obtained for diluted samples ( R = 0.98, P = 0.003) than for undiluted
( R = 0.94, P = 0.01).
the potential of mid-infrared spectroscopy for the chemical study of carotenoids, have been established a few decades ago [87]. however, the recent research
has depicted the capability of this technique for the simultaneous quantitative and
qualitative determination of carotenoids i.e. lycopene and β-carotene in fruits like
tomatoes [43, 88]. Fig. 10.11 depicts an example of the correlation between lycopene content in different tomato varieties measured by mid-IR and hPLC methods.
the authors analyzed the 950–980 cm
−1
infrared region where C = C trans double
bonds absorb and used partial least square regression (PLSR) to produce calibration
models that correlate lycopene or β-carotene concentration in standards (as determined by uv-vis spectroscopy) with their infrared spectra. the achieved correlation factors were satisfying ( R
2
= 0.95), thus the PLSR calibration models were then
used to predict the lycopene concentration in commercial and experimental tomato
varieties using their infrared spectra.
those research were coherent with earlier studies [10] showing the application
of three different types of spectroscopies (Ft-Raman, AtR IR, and NIR Spectroscopy) in carotenoids analysis. As a results authors got the best correlation with hPLC