Sample preparation methods for beeswax characterization by gas chromatography with flame ionization detection

Assessment of Beeswax Adulteration by Paraffin and Stearic Acid Using ATR-IR Spectroscopy and Multivariate Statistics-An Analytical Method to Detect Fraud

A spectroscopic investigation of beeswax adulteration by paraffin and/or stearic acid was undertaken via Attenuated Total Reflectance Infra-Red spectroscopy (ATR-IR) combined with multivariate statistical analyses. Principal Component Analysis (PCA) was successfully applied for the first time as an exploratory tool for the differentiation among pure beeswax and adulterated beeswax by paraffin and stearic acid with detection limits (LOD) of ~5% and 1%, respectively. Partial Least Square (PLS) modelling was used to build chemometric models based on beeswax/paraffin and beeswax/stearic acid calibration mixtures and subsequently used to predict concentrations of paraffin and stearic acid on a set of unknown test samples. PLS predictions demonstrated that beeswax adulteration by paraffin is much more prominent (74%) than the one by stearic acid (26%) and that commercial beeswax products (candles, pearls, blocks, etc.) are more prone to adulteration (27%) than honeycomb-type samples (12.5%).

Bee Products: An Emblematic Example of Underutilized Sources of Bioactive Compounds

Beside honey, honeybees (Apis mellifera L.) are able to produce many byproducts, including bee pollen, propolis, bee bread, royal jelly, and beeswax. Even if the medicinal properties of these byproducts have been recognized for thousands of years by the ancient civilizations, in the modern era, they have a limited use, essentially as nutritional supplements or health products. However, these natural products are excellent sources of bioactive compounds, macro- and micronutrients, that, in a synergistic way, confer multiple biological activities to these byproducts, such as, for example, antimicrobial, antioxidant, and anti-inflammatory properties. This work aims to update the chemical and phytochemical composition of bee pollen, propolis, bee bread, royal jelly, and beeswax and to summarize the main effects exerted by these byproducts on human health, from the anticancer and immune-modulatory activities to the antidiabetic, hypolipidemic, hypotensive, and anti-allergic properties.

Hydrophobicity Characterization of Bio-Wax Derived from Taro Leaf for Surface Coating Applications

The hydrophobic properties as well as the presence of 1-octacosanol of taro wax extracted from taro leaf were investigated using various analytical techniques. The bio-wax extraction was achieved by immersing taro leaves samples in 500 mL chloroform at 50°C for 30 seconds and the step was repeated for the same sample using fresh chloroform. The solvent was evaporated using rotary evaporator and the raw bio-wax solution was obtained. Hydrophobicity test showed the average time for the test was 981s which exceeded the 300 s limited for hydrophilicity. TGA results indicate the existence of multi-components in taro wax with the decomposition occurring at three stages. The DSC result showed that the taro wax is composed of at least two contents, ie lower content with smaller melting point range of 50 to 60°C as well as upper content with higher melting point range of 65 to 75°C. Contact angle of droplets of distilled water on the taro wax surfaces were found to be greater than 900 and this confirmed its hydrophobic property. The n-octacosanol presented was identified through FTIR and GC-FID analyses. The functional compounds OH, CH3, CH2, and C=O were detected. From the GC-FID, the n-octacosanol was presented at 34.5 min compared to the standard solution. Plant base taro wax can be a source of sustainable and renewable hydrophobic material for use in HVAC application system.

Authentication of beeswax (Apis mellifera) by high-temperature gas chromatography and chemometric analysis

Chemical characterization and authentication of beeswax of Apis mellifera was performed by high temperature capillary gas chromatography coupled to electron impact mass spectrometry or to flame ionisation detection and chemometric analysis. Many major components (>50) of beeswax, odd and even hydrocarbons, oleofin, palmitate, oleate and hydroxypalmitate monoesters were detected, and for the first time palmitate and oleate monoesters esterified with 1-octadecanol and 1-eicosanol are reported to be present in beeswax. Unsupervised pattern recognition procedures, cluster analysis and principal component analysis, were used to find data patterns and successfully differentiate authentic and paraffin adulterated beeswax based on the chemical profile obtained. Independent assessment of beeswax quality and performance of the unsupervised classification methods were performed using classical analytical parameters. The discrimination power of the chemometric unsupervised methods for detection of paraffin adulterated beeswax was superior to the discriminating power of classical analytical parameters. Using linear discriminant analysis, classification rules for authentic and paraffin adulterated beeswax samples were developed. The model was validated by leave-one-out cross validation and showed good recognition and prediction abilities, 100% and 99%, respectively.

Detection of adulterated commercial Spanish beeswax

The physical and chemical parameters (melting point and saponification number), and the fraction of hydrocarbons, monoesters, acids and alcohols have been determined in 90 samples of Spanish commercial beeswax from Apis mellifera L. The adulteration with paraffins of different melting point, cow tallow, stearic acid, and carnauba wax were determined by HTGC-FID/MS detection, and the research was focussed mainly on paraffins and microcrystallines waxes. In general, the added adulterant can be identified by the presence of non-naturally beeswax components, and by the differences of values of selected components between pure and adulterated beeswax. The detection limits were determined using pure and adulterated beeswax with different amounts of added waxes (5%, 10%, 20% and 30%). Percentages higher than 1-5% of each adulterant can be detected in the mixtures. Paraffin waxes were confirmed in 33 of the 90 samples analysed at concentrations between 5% and 30%.

Profile and relative concentrations of fatty acids in corn and soybean seeds from transgenic and isogenic crops

In this work 44 fatty acids, which were analyzed as methyl esters by GC/MS in scan mode, have been determined in genetically modified corn and soybean seeds. Their relative concentrations have been compared with those of isogenic lines grown in the same conditions. Studied compounds comprised saturated and unsaturated fatty acids, including cis/trans isomers and minor fatty acids. A classical soxhlet extraction and an accelerated solvent extraction have been assayed to extract the fatty compounds from seeds and the GC separation has been carried out on a biscyanopropylpolysiloxane chromatographic column. Soxhlet extraction was selected as the most convenient and applied to compare the samples. Specific compounds, which could denote the origin of the crop have not been observed, but for some sample pairs, significant differences have been found in relation to the percentage of certain acids; the highest differences for major acids were 4.1% in corn and 4.8% in soybean. The concentrations of long chain acids such as 24:0, 26:0 and 28:0 were higher in some isogenic lines whereas the concentrations of short chain acids such as 6:0, 8:0, 9:0, 10:0 and 12:0 were higher in their transgenic counterparts.