Discoloration and Adsorption of Acaricides from Beeswax

Abstract

The bleaching effect of solid adsorbent material was evaluated on acaricides residues during the recycling of old wax combs process. The effect of parameters such as initial concentration, moisture level, clay dosing, temperature, particle size, agitation time, Freundlich isotherm and kinetic adsorption were investigated and simulated in pilot plant following industry guidelines. The efficiency capacity of sorbent was assayed in optimal conditions on different levels of chlorfenvinphos, tau‐fluvalinate and coumaphos residues from 0.015 to 88.6 mg/kg, identified in 66 samples of commercial beeswaxes analyzed before and after the process of refination. Experimental results indicated that the use of a dough formed by active carbon (Norit SA4 PAH) and bleaching earth (Tonsil Supreme 114 FF) in the proportion (0.04/4.0 wt % beeswax) under bleaching conditions [agitation (250 rpm) for 45 min working at 90°C under atmospheric pression] was very efficient to reduce color (>80%) and amount of chlorfenvinphos (93.4 ± 7.40%) and coumaphos (93.1 ± 3.90%). But, lower affinity was identified in tau‐fluvalinate pyrethroid (average, 35%) with large variations (13.7–73.9%). The Lagergen pseudo‐first‐order kinetic model was appropriate to organophosphorus acaricides sorption with coefficients of correlation R2 = 0.95 for all initial concentrations studied. Practical Applications Beeswax is a complex mixture of paraffinic hydrocarbons, esters of fatty acids and alcohols, diesters, free fatty acids and alcohols produced by the worker bee. An important aspect is the recycling of beeswax after the extraction of honey. At first, its color is white, but after the bees’ manipulation, it changes from yellow to brownish originated from propolis and pollen pigments. If beeswax is dark its value is much lower. Thus, bleaching is one the most important steps in recycled beeswax. Furthermore, in the last ten years, the accumulated acaricides residues used in the fight against Varroa destructor are clearly detected in commercial beeswaxes limiting its use as an authorised food additive in the EU (code E901). The idea of simultaneous bleaching and decontamination process was introduced in this work to recycle beeswax. The results indicated that the adsorption was very effective in a beeswax melting solution with a simple and economical application.

Industrial-Scale Decontamination Procedure Effects on the Content of Acaricides, Heavy Metals and Antioxidant Capacity of Beeswax

“…Two cycles of filtration could only eliminate 636 out of 2113 ppb of tau fluvalinate, which led to a 30% of reduction. These percentage reductions are in the same range as those reported in previous studies on Spanish beeswax [7], on palm oil at laboratory-scale [16] and on industrial edible oils [17] and are consistent with other studies performed on olive oil [18]. These findings highlight the relevance of the molecule type and its liposolubility in the filtration process, with the pyrethroid pesticide the most lipophilic and the least eliminated.…”

“…Consistent with these results, the industrial method tested for decontamination displayed its effectiveness to remove pesticide contents in beeswax samples, especially organophosphate acaricides. Therefore, the industrial reproducibility of the decontamination method performed at laboratory scale by Bonvehi & Orantes-Bermejo [7] is proven in the present study.…”

“…These findings highlight the relevance of the molecule type and its liposolubility in the filtration process, with the pyrethroid pesticide the most lipophilic and the least eliminated. Furthermore, the incomplete elimination of organophosphates could be explained by their competition with monoesters for adsorption sites [7].…”

“…Recently, our research group has tested a wax decontamination protocol [7] at a pilot scale. This new protocol sought to avoid the use of chemical agents for the bleaching of used beeswax, since these agents altered the composition of the wax and barely managed to reduce its degree of contamination [7]. The results obtained were promising, with decreases in the concentrations of highly representative chemicals.…”

Beeswax cleaning by solvent extraction of pesticides

“…In this sense, methods developed propose the use of solid sorbents, like the patent US6586610B2 [8]. Serra Bonvehi and Jose Orantes-Bermejo [9], proved that activated charcoal is able to remove >95% of two organophosphorus —coumaphos and chlorfenvinphos—, widely detected in beeswax worldwide. However, this sorbent only removed fluvalinate pyrethroid a 35%.…”