Validation of analytical methods for the detection of beeswax adulteration with a focus on paraffin

1H NMR spectra modeling for predicting the acid, saponification, and iodine values of bio-waxes derived from vegetable oils

Bio-waxes from vegetable oils are of recent interest due to the high availability of raw materials and their applications in the pharmaceutical, cosmetic, and food industries. The acid (AV), saponification (SV) and iodine (IV) values in bio-waxes are critical properties for strict quality control. In this work, the AV, SV and IV were predicted from 1H NMR spectra and chemometric methods including Partial Least Squares Regression (PLSR) and Principal Component Regression (PCR). PLSR yielded the best results with R2 above 0.95 for the three properties, and root-mean-square error of cross-validation (RMSECV) below 2 mg KOH/g, 5 mg KOH/g, and 3 g I2/100 g for the AV, SV and IV, respectively. The developed models rely on both compositional and structural information, particularly on the alkyl chain length negative contribution and the RCOOH, RCOOR1 and RCHCHR1 groups positive contribution. The proposed strategy offers a rapid, low-cost, and greener alternative to conventional methods.

The Influence of the Chemical Composition of Beeswax Foundation Sheets on Their Acceptability by the Bee's Colony

Beeswax is one of the most important products for the well-being of bee colonies. The wax glands of young worker bees produce beeswax, which serves as a building material for honeycomb construction. Beekeepers using hives with mobile frames mainly utilize local beeswax to make foundations. Any paraffin addition represents adulteration, resulting in a high degree of contamination. During the preparation of re-used beeswax, losses during the process may instigate producers to add cheaper, wax-like substances like paraffin and tallow. This article presents a systematic investigation of the quality of beeswax foundation from six major producers in Vojvodina, Serbia, by applying the classic analytical procedure for the determination of selected physicochemical parameters and instrumental gas chromatography coupled with mass spectrometry (GC-MS) and Fourier transform infrared attenuated total reflection (FTIR-ATR) spectroscopy techniques. FTIR-ATR detected possible paraffin and beef tallow in 72 foundation sheet samples. This technique was complemented with GC-MS. This analysis revealed that paraffin content ranged between 19.75 and 85.68%, while no tallow was detected over the two-year period. Two sheets from each manufacturer were placed into wired Langstroth-Ruth frames and placed in beehives. The construction, based on built cells, was monitored every 24 h. Evaluating newly inserted sheets proved that without quality nectar, there is no intensive building, regardless of adulteration.

How does adulteration of wax foundation affect phenoloxidase and lysozyme activities as selected parameters of immunity in Apis mellifera?

Introduction

The adulteration of wax foundation is, for many reasons, a growing problem of modern beekeeping not only in Europe but also around the world. Wax foundation contaminated with stearin addition leads to a brood die-off, while paraffin addition negatively affects the strength of combs. It is tenable that such adulterated wax foundation reduces bees' immunity. The aim of the study was to determine the activities of two bee immune enzymes, lysozyme and phenoloxidase, in the haemolymph of worker bees which had emerged from combs with wax foundations contaminated with stearin or paraffin.

Material and Methods

Combs built with stearin- or paraffin-adulterated wax (both adulterants at concentrations of 10%, 30% or 50%) or pure wax (0% adulterated) foundations were placed in the colonies, one for each adulterant and percentage. The workers were marked upon emergence from these combs and those bees were introduced into one strong colony per adulterant and percentage. Phenoloxidase and lysozyme activities were determined in the haemolymph of 1-, 7- and 14-day-old workers.

Results

The higher the concentrations of stearin and paraffin in the wax foundation, the lower the phenoloxidase activities were. These activities increased with the bee age. In contrast, the trends in lysozymes were opposite. Paraffin seems to be less toxic than stearin.

Conclusion

Adulteration of wax foundation with even a small amount of stearin or paraffin has negative effects on the functioning of the bee.

Adulteration of beeswax: A first nationwide survey from Belgium

Beeswax is intended for use in the beekeeping sector but also in the agro-food, pharmaceutical or cosmetics sectors. The adulteration of beeswax is an emerging issue that was reported lately at several occasions in the scientific literature. This issue tends to become more frequent and global, but its exact extent is not accurately defined. The present study aims to assess the current situation in Belgium through a nationwide survey. Randomized beeswax samples originating from Belgian beekeepers (N = 98) and commercial suppliers (N = 9) were analysed with a Fourier transform infrared spectroscopy (FTIR) coupled with Attenuated Total Reflectance (ATR) accessory (FTIR-ATR spectroscopy) for adulteration. The survey revealed a frequency of 9.2% and 33.3% of adulteration in beekeepers beeswax samples (9 samples out of 98: 2 with paraffin and 7 with stearin/stearic acid) and commercial beeswax samples (3 samples out of 9: all adulterated with stearin/stearic acid), respectively. The analysed samples were adulterated with various percentages of paraffin (12 to 78.8%) and stearin/stearic acid (1.2 to 20.8%). This survey indicates that in the beekeepers samples, beeswax adulteration was more frequent in comb foundation and crude beeswax than in comb wax. With the example of this nationwide survey conducted in Belgium, this study shows the emergence of the issue and the urgent need for action to safeguard the health of both honey bees health and humans, in particular with the setting of a proper regulation legal framework and a specific routine analytical testing of commercial beeswax to ensure beeswax quality.