Fachartikel in Englisch über die Entwicklung einer Routinewachsanalytik mit Ergebnissen zu den Paraffinbeimengungen handelsüblicher Mittelwände. Demnach hatten 89% der Proben (die auch aus Deutschland stammten) bis zu 20% Paraffin-Beimischungen.
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Although beeswax adulteration represents one of the main beeswax quality issues, there
are still no internationally standardised analytical methods for routine quality control.
The objective of this study was to establish an analytical procedure suitable for routine
detection of beeswax adulteration using FTIR-ATR spectroscopy. For the purpose of this
study, reference IR spectra of virgin beeswax, paraffin, and their mixtures containing different proportions of paraffin (5 - 95%), were obtained. Mixtures were used for the establishment of calibration curves. To determine the prediction strength of IR spectral data
for the share of paraffin in mixtures, the Partial Least Squares Regression method was
used. The same procedure was conducted on beeswax-beef tallow mixtures. The model
was validated using comb foundation samples of an unknown chemical background which
had been collected from the international market (n = 56). Selected physico-chemical parameters were determined for comparison purposes. Results revealed a strong predictive
power (R2 = 0.999) of IR spectra for the paraffin and beef tallow share in beeswax. The
results also revealed that the majority of the analysed samples (89%) were adulterated
with paraffin; only 6 out of 56 (11%) samples were identified as virgin beeswax, 28% of
the samples exhibited a higher level of paraffin adulteration (>46% of paraffin), while
the majority of the analysed samples (50%) were found to be adulterated with 5 - 20% of
paraffin. These results indicate an urgent need for routine beeswax authenticity control.
In this study, we demonstrated that the analytical approach defining the standard curves
for particular adulteration levels in beeswax, based on chemometric modelling of specific
IR spectral region indicative for adulteration, enables reliable determination of the adulterant proportions in beeswax.