The composition of beeswax and other waxes secreted by insects

Improvement of lidocaine skin permeation by using passive and active enhancer methods

Lidocaine is generally recognized and preferred for local anaesthesia, but in addition, studies have described additional benefits of lidocaine in cancer therapy, inflammation reduction, and wound healing. These properties contribute to its increasing importance in dermatological applications, and not only in pain relief but also in other potential therapeutic outcomes. Therefore, the purpose of our study was to enhance lidocaine delivery through the skin. A stable nanostructured lipid carrier (NLC), as a passive permeation enhancer, was developed using a 23 full factorial design. The nanosystems were characterized by crystallinity behaviour, particle size, zeta potential, encapsulation efficiency measurements, and one of them was selected for further investigation. Then, NLC gel was formulated for dermal application and compared to a traditional dermal ointment in terms of physicochemical (rheological behaviour) and biopharmaceutical (qualitative Franz diffusion and quantitative Raman investigations) properties. The study also examined the use of 3D printed solid microneedles as active permeation enhancers for these systems, offering a minimally invasive approach to enhance transdermal drug delivery. By actively facilitating drug permeation through the skin, microneedles can complement the passive transport achieved by NLCs, thereby providing an innovative and synergistic approach to improving lidocaine delivery.

Metabolism, digestion, and horizontal transfer: potential roles and interaction of symbiotic bacteria in the ladybird beetle Novius pumilus and their prey Icerya aegyptiaca

In this study, we first time sequenced and analyzed the 16S rRNA gene data of predator ladybird beetles Novius pumilus and globally distributed invasive pest Icerya aegyptiaca at different stages, and combined data with bacterial genome sequences in N. pumilus to explored the taxonomic distribution, alpha and beta diversity, differentially abundant bacteria, co-occurrence network, and putative functions of their microbial community. Our finding revealed that Candidatus Walczuchella, which exhibited a higher abundance in I. aegyptiaca, possessed several genes in essential amino acid biosynthesis and seemed to perform roles in providing nutrients to the host, similar to other obligate symbionts in scale insects. Lactococcus, Serratia, and Pseudomonas, more abundant in N. pumilus, were predicted to have genes related to hydrocarbon, fatty acids, and chitin degradation, which may assist their hosts in digesting the wax shell covering the scale insects. Notably, our result showed that Lactococcus had relatively higher abundances in adults and eggs compared to other stages in N. pumilus, indicating potential vertical transmission. Additionally, we found that Arsenophonus, known to influence sex ratios in whitefly and wasp, may also function in I. aegyptiaca, probably by influencing nutrient metabolism as it similarly had many genes corresponding to vitamin B and essential amino acid biosynthesis. Also, we observed a potential horizontal transfer of Arsenophonus between the scale insect and its predator, with a relatively high abundance in the ladybirds compared to other bacteria from the scale insects.IMPORTANCEThe composition and dynamic changes of microbiome in different developmental stages of ladybird beetles Novius pumilus with its prey Icerya aegyptiaca were detected. We found that Candidatus Walczuchella, abundant in I. aegyptiaca, probably provide nutrients to their host based on their amino acid biosynthesis-related genes. Abundant symbionts in N. pumilus, including Lactococcus, Serratia, and Pseudophonus, may help the host digest the scale insects with their hydrocarbon, fatty acid, and chitin degrading-related genes. A key endosymbiont Arsenophonus may play potential roles in the nutrient metabolisms and sex determination in I. aegyptiaca, and is possibly transferred from the scale insect to the predator.

Effect of coating using beeswax and sodium nitroprusside on chlorophyll stability and quality factors of lime during cold storage

Lime (Citrus floridana) is a quickly perishable fruit, limiting its shelf life because of reduced chlorophyll content and post-harvest quality under different storage conditions. To increase chlorophyll stability as well as other quality factors of limes, they were coated with beeswax in 0.1 wt.% and sodium nitroprusside in three various concentrations (0.1, 0.2, and 0.4 mM) at 25 °C for 3 min and then stored at 8 °C for 60 days. In this research, changes in weight loss, juice content, firmness (F), chlorophyll, chlorophyllase activity, polyphenol oxidase activity, color, total acidity (titratable acidity), ascorbic acid (ASA) and sensory evaluation were studied. During storage at low temperatures, BW surface coating (0.1%) alone, sodium nitroprusside alone, and also in combination with each other and a double layer were effective in maintaining chlorophyll and the qualitative characteristics of limes. In our observations, the best treatment was the treatment where the limes were coated by beeswax enriched by sodium nitroprusside coating. This treatment contained the highest content of lime juice and the highest chlorophyll plus the lowest activity of chlorophyllase and polyphenol oxidase, while the amount of green color was maintained to a large extent. As a result, it is possible to use beeswax enriched by sodium nitroprusside coating method to maintain the quality and chlorophyll of cold-stored lime fruits.

From Hive to Highway: Waste Honeycombs as a Sustainable Modifier for Asphalt Binder Formulations in South Korea

Navigating the crossroads of sustainable infrastructure and innovative waste management, this research unveils the potential of waste honeycombs (WHCs)-an overlooked byproduct of apiculture-as a potent modifier for asphalt binder formulations. This endeavor addresses the dual challenge of enhancing road pavement sustainability and mitigating environmental degradation. A meticulous methodology evaluated the impact of varying WHC concentrations (5, 10, and 15 wt.%) on the asphalt binder, examining its attributes pre- and post-aging. Employing an array of analytical tools-thin-layer chromatography-flame ionization detection (TLC-FID); Fourier transform-infrared spectroscopy (FT-IR); scanning electron microscopy (SEM); thermogravimetric analysis (TGA); and a suite of conventional tests such as penetration, softening point, viscosity, ductility, dynamic shear rheometer (DSR), and multiple stress-creep recovery (MSCR)-provided a comprehensive insight into the binder's behavior. TLC-FID analyses revealed that WHC, with its 92 wt.% resin content, altered the SARA profile across distinct aging conditions, notably reducing asphaltene content, a factor linked to binder stiffness. The colloidal instability index (IC) further attested to this, pointing to a more thermodynamically stable system with WHC's inclusion. Meanwhile, FT-IR confirmed a physical interaction between WHC and asphalt without introducing new chemical entities. SEM observations highlighted the superior miscibility of WHC with asphalt, evidenced by a unique microtexture. With marked precision, TGA assessments unveiled a bolstering of asphalt's inherent thermal resilience consequent to a minor WHC integration. From the conventional tests, shifts in penetration, softening point, and viscosity were observed, with reduced viscosity, indicating improved workability. Lastly, while rutting potential was sensitive to WHC concentrations, fatigue resistance notably heightened with minor to moderate WHC inclusions. In essence, this pioneering study advocates for WHC's integration into asphalt formulations, offering enhanced road performance coupled with sustainable waste utilization. The findings underscore the synergy between environmental stewardship and infrastructural advancement.

Sterol and lipid metabolism in bees

BACKGROUND

Bees provide essential pollination services for many food crops and are critical in supporting wild plant diversity. However, the dietary landscape of pollen food sources for social and solitary bees has changed because of agricultural intensification and habitat loss. For this reason, understanding the basic nutrient metabolism and meeting the nutritional needs of bees is becoming an urgent requirement for agriculture and conservation. We know that pollen is the principal source of dietary fat and sterols for pollinators, but a precise understanding of what the essential nutrients are and how much is needed is not yet clear. Sterols are key for producing the hormones that control development and may be present in cell membranes, where fatty-acid-containing species are important structural and signalling molecules (phospholipids) or to supply, store and distribute energy (glycerides).

AIM OF THE REVIEW

In this critical review, we examine the current general understanding of sterol and lipid metabolism of social and solitary bees from a variety of literature sources and discuss implications for bee health.

KEY SCIENTIFIC CONCEPTS OF REVIEW

We found that while eusocial bees are resilient to some dietary variation in sterol supply the scope for this is limited. The evidence of both de novo lipogenesis and a dietary need for particular fatty acids (FAs) shows that FA metabolism in insects is analogous to mammals but with distinct features. Bees rely on their dietary intake for essential sterols and lipids in a way that is dependent upon pollen availability.

Beeswax: A review on the recent progress in the development of superhydrophobic films/coatings and their applications in fruits preservation

Recently, the design and fabrication of bio-inspired superhydrophobic materials using natural lipid additives such as beeswax (BW) have aroused great attention in food packaging as they can minimize the transfer rate of water molecules and have effective moisture barriers. This review discusses the recent progress in the design and fabrication of BW-containing edible films/coatings (e.g., emulsion and blend films, bilayer materials, bionanocomposites, and antimicrobial materials) and their potential applications on the postharvest life and quality attributes of various fruits. Incorporation of BW into polysaccharides- and proteins-based emulsion films effectively improved their hydrophobicity, water vapor, and UV/visible light barrier properties, as well as the film tensile properties. The addition of nanoparticles to BW-based polymeric matrices often results in improved physico-mechanical properties. BW coatings have been also applied to prolong the shelf-life of various climacteric fruits, however, optimization of the wax concentration can be further investigated to develop targeted food storage systems.

Stabilization of an Aqueous Bio-Based Wax Nano-Emulsion through Encapsulation

The emulsification of biowaxes in an aqueous environment is important to broaden their application range and make them suitable for incorporation in water-based systems. The study here presented proposes a method for emulsification of carnauba wax by an in-situ imidization reaction of ammonolysed styrene (maleic anhydride), resulting in the encapsulation of the wax into stabilized organic nanoparticles. A parameter study is presented on the influences of wax concentrations (30 to 80 wt.-%) and variation in reaction conditions (degree of imidization) on the stability and morphology of the nanoparticles. Similar studies are done for encapsulation and emulsification of paraffin wax as a reference material. An analytical analysis with Raman spectroscopy and infrared spectroscopy indicated different reactivity of the waxes towards encapsulation, with the bio-based carnauba wax showing better compatibility with the formation of imidized styrene (maleic anhydride) nanoparticles. The latter can be ascribed to the higher functionality of the carnauba wax inducing more interactions with the organic nanoparticle phase compared to paraffin wax. In parallel, the thermal and mechanical stability of nanoparticles with encapsulated carnauba wax is higher than paraffin wax, as studied by differential scanning calorimetry, thermogravimetric analysis and dynamic mechanical analysis. In conclusion, a stable aqueous emulsion with a maximum of 70 wt.-% encapsulated carnauba wax was obtained, being distributed as a droplet phase in 200 nm organic nanoparticles.

Assessment of Natural Waxes as Stabilizers in Peanut Butter

Manufacturers add sugar and fully hydrogenated vegetable oils to peanut butter to avoid its oil separation during storage. Unfortunately, hydrogenated oils are significant sources of saturated fats, and reducing their consumption is challenging for food scientists without affecting the desired characteristics of food products. Therefore, in a preliminary study, 1%, 1.5%, and 2% of three natural waxes (rice bran, carnauba, and beeswax) were added to the natural peanut butter to test their efficacy as a stabilizer. Rice bran and carnauba wax added to peanut butter presented a higher elastic modulus (G’) and lower oil separation percentages than beeswax. However, no significant differences were found between the different percentages of waxes. Thus, in the final experiments, 1% of these selected waxes (rice bran and carnauba waxes) were added directly to the roasted ground peanut. Due to the difficulty of adding high melting point waxes to the peanut butter, a second experiment added wax oleogel (rice-bran and carnauba wax) to defatted peanut flour. After four weeks of storage, all of the samples were examined for their texture (TPA) and oil separation. The sample with directly added bran wax had the highest values for spreadability and firmness, and the lowest oil separation, which was 11.94 ± 0.90 N·s⁻¹, 19.60 ± 0.71 N·s⁻¹, and 0.87 ± 0.05%, respectively. In the peanut flour sample, the spreadability, firmness, and separated oil of the rice bran wax oleogel added sample were 46.95 ± 0.99 N·s⁻¹, 66.61 ± 0.93 N, and 1.57 ± 0.07%, respectively. However, the textural properties of the rice bran wax oleogel added sample were close to the commercial peanut butter (natural and creamy). Therefore, the results indicate that the rice bran wax oleogel could be the potential replacement of the fully hydrogenated oil as a stabilizer.

Chemical Conversion of Fischer–Tropsch Waxes and Plastic Waste Pyrolysis Condensate to Lubricating Oil and Potential Steam Cracker Feedstocks

The global economy and its production chains must move away from petroleum-based products, to achieve this goal, alternative carbon feedstocks need to be established. One area of concern is sustainable production of synthetic lubricants. A lubricating oil can be described as a high boiling point (>340 °C) liquid with solidification at least below room temperature. Historically, many lubricants have been produced from petroleum waxes via solvent or catalytic dewaxing. In this study, catalytic dewaxing was applied to potential climate neutral feedstocks. One lubricant was produced via Fischer–Tropsch (FT) synthesis and the other lubricant resulted from low temperature pyrolysis of agricultural waste plastics. The waxes were chosen because they each represented a sustainable alternative towards petroleum, i.e., FT waxes are contrivable from biomass and CO2 by means of gasification and Power-to-X technology. The pyrolysis of plastic is a promising process to complement existing recycling processes and to reduce environmental pollution. Changes in cloud point, viscosity, and yield were investigated. A bifunctional zeolite catalyst (SAPO-11) loaded with 0.3 wt% platinum was used. The plastic waste lubricants showed lower cloud points and increased temperature stability as compared with lubricants from FT waxes. There was a special focus on the composition of the naphtha, which accumulated during cracking. While the plastic waste produced higher amounts of naphtha, its composition was quite similar to those from FT waxes, with the notable exception of a higher naphthene content.

Texture and flavor evaluation of peanut butter stabilized with natural waxes

Natural peanut butter was stabilized with 1.0%-2.0% (w/w) beeswax (BW), candelilla wax (CLW), rice bran wax (RBW), or sunflower wax (SFW). The appearance, spreadability, mouthfeel, and flavor attributes of these samples were evaluated by a trained sensory panel using commercial stabilized peanut butter and a sample stabilized with hydrogenated cottonseed oil as references. The waxes and their blend ratio significantly (p < 0.05) influenced appearance, spreadability, firmness, mouthfeel, and flavor attributes. Samples with 1.5%-2.0% CLW, or 1.0%-1.5% RBW had the fewest differences in appearance and texture from the reference and commercial samples. However, an off-flavor was attributed to 1.5% or higher CLW. Samples stabilized with BW or with 1.0%-1.5% RBW had the fewest difference in flavor compared to the reference sample. Overall, samples stabilized with 1.0%-1.5% RBW scored closest to the commercial and reference samples. The response of CLW, RBW, and SFW (which was only evaluated for appearance and spreadability) indicates that amounts of these waxes could be tailored in different products to achieve a product with desirable texture and flavor as well as stability to oil loss. PRACTICAL APPLICATION: This research provides information that could be used by food companies that make seed or nut butters as spreads or as ingredients for use in foods. It shows the impact of the use of four types of waxes as stabilizers, at commercially relevant levels (< 3.0%), and at levels previously shown to be effective for stabilization, on the firmness, spreadability, and other texture and flavor attributes, and thus provides a starting point for optimization for commercial product specifications.

Bee products in the prehistoric southern levant: evidence from the lipid organic record

Beehive products have a rich global history. In the wider Levantine region, bees had a significant role in Egypt and Mesopotamia, and intensive beekeeping was noted in Israel during the Biblical period when apiaries were first identified. This study investigates the origins of this extensive beekeeping through organic residue analysis of pottery from prehistoric sites in the southern Levant. The results suggest that beehive products from likely wild bees were used during the Chalcolithic period as a vessel surface treatment and/or as part of the diet. These functions are reinforced by comparison to the wider archaeological record. While the true frequency of beeswax use may be debated, alternatives to beehive products were seemingly preferred as wild resources contrasted with the socio-economic system centred on domesticated resources, controlled production and standardization. Bee products only became an important part of the economic canon in the southern Levant several millennia later.

Characterization of Beeswax, Candelilla Wax and Paraffin Wax for Coating Cheeses

A study on the physical and mechanical properties of beeswax (BW), candelilla wax (CW), paraffin wax (PW) and blends was carried out with the aim to evaluate their usefulness as coatings for cheeses. Waxes were analyzed by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), differential scanning calorimetry (DSC), permeability, viscosity, flexural and tensile tests and scanning electron microscopy. Cheeses were coated with the waxes and stored for 5 weeks at 30 °C. Measured parameters were weight, moisture, occurrence and degree of fractures, and dimensional changes. The crystal phases identified by XRD for the three waxes allowed them to determine the length of alkanes and the nonlinear compounds in crystallizable forms in waxes. FTIR spectra showed absorption bands between 1800 and 800 cm−1 related to carbonyls in BW and CW. In DSC, the onset of melting temperature was 45.5 °C for BW, and >54 °C for CW and PW. Cheeses coated with BW did not show cracks after storage. Cheeses coated with CW and PW showed microcraks, and lost weight, moisture and shrunk. In the flexural and tensile tests, BW was ductile; CW and PW were brittle. BW blends with CW or PW displays a semi ductile behavior. Cheeses coated with BW blends lost less than 5% weight during storage. The best waxes were BW and the blends.

Microencapsulation of retinyl palmitate by melt dispersion for cosmetic application

Retinyl palmitate was encapsulated in wax matrix by melt dispersion for the purpose of economic and sustainable cosmeceutical formulation with minimum use of synthetic chemicals. We evaluated the effect of different process variables of microencapsulation by melt dispersion. In this study, a three level definitive screening design was applied, where the microcapsule properties were analysed through statistical analysis to understand the effect of four process variables: type of wax, theoretical loading capacity, surface concentration and stirring speed. Microparticles were characterised for size using image analysis; loading capacity and encapsulation efficiency using ultraviolet-visible spectroscopy; antioxidant activity through DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. Melt dispersion method was effective to produce microcapsules with a spherical shape and mean size as small as 28 µm. The encapsulation efficiency ranged 60-80%. Theoretical loading capacity (p-value = 0.00232, significance level, α = 1%) and surfactant% (p = 0.0573, α = 10%) were found to be the most significant factors to control the actual loading capacity and size of microcapsules.

A comparative study on the artificial UV and natural ageing of beeswax and Chinese wax and influence of wax finishing on the ageing of Chinese Ash (Fraxinus mandshurica) wood surfaces

This study investigated and compared the behaviour of two types of natural waxes, beeswax and Chinese wax, by means of two different ageing tests: an artificial accelerated ageing test using UV light and a simulated natural ageing test (indoors conditions) based on the action of natural, window-filtered light. The same tests were employed to evaluate the influence of wax finishing on the ageing behaviour of Chinese Ash (Fraxinus mandshurica) wood surfaces. Ageing effects were evaluated by direct and microscopic observation, colour measurements in the CIELab system and FTIR investigations. The results yielded by both accelerated UV ageing (72 h) and simulated indoors natural ageing (6 months) indicate that the waxes under analysis here are materials with a good ageing resistance. FTIR investigation revealed only minor chemical changes following ageing, more evident with beeswax than with Chinese wax. Finishing Chinese Ash wood surfaces with the two types of waxes influenced their ageing behaviour in terms of colour and surface chemistry changes. For both UV and natural ageing the maximum colour differences occurred for the samples finished with Chinese wax. The colour differences ΔE after 72 h accelerated UV ageing were in all the cases higher than those occurring after 6 months of indoors simulated natural ageing. Acceleration indexes for UV exposure compared to exposure to natural window-filtered sunlight, of about 40X-60X, were calculated. Both UV accelerated ageing and natural simulated ageing resulted in significant surface chemistry changes for the unfinished Chinese ash wood samples, consisting mostly in lignin degradation and formation of carbonyl containing chromophores. FTIR investigation of wax finish wood samples revealed only very minor chemical changes of the top wax layers, although chemical changes occurring beneath the coating layer on the wood surface are highly probable. Overall, the experiments presented in this paper indicate that Chinese wax seems slightly more resistant to ageing than beeswax.

Measuring the permeability of thin solid layers of natural waxes

HYPOTHESIS

Previous experimental work has shown that microcapsule walls, made by solidification of a molten wax, are unexpectedly permeable. The hypothesis was that this was due more to the structure of the wall than the material itself.

EXPERIMENTS

The permeability of thin (sub and low micron thickness) natural waxes was measured where a membrane was placed between two cells and the diffusion of a dye (fluorescein) measured. A filter paper was used to support the membranes. Two methods were used to coat the filter paper; simple dipping and spin coating. The resulting surfaces were examined using SEM, XRD and contact angle.

FINDINGS

Results indicate that the permeability of very thin walled capsules can be investigated by forming a layer on a porous support and measuring diffusion rates. Both the composition of the wax and the sample preparation is extremely important to the structure and resulting permeability of the membranes. Spin coating was much more effective than dip coating in reducing permeability. Carnauba wax had a much lower permeability than beeswax. A difference in levels between the two cells was observed, indicating a potential Osmotic pressure difference at play which should be further investigated.

Thermal, Mechanical, Viscoelastic and Morphological Properties of Poly(lactic acid) based Biocomposites with Potato Pulp Powder Treated with Waxes

The thermal, mechanical and viscoelastic properties of biocomposites of poly(lactic acid) (PLA) with 20 wt.% of potato pulp powder were investigated. The potato pulp powder utilized is a byproduct from the production and extraction of starch. The results showed that the potato pulp powder does not act as reinforcement, but as filler for PLA, due to an unfavorable aspect ratio and the irregular shape of the particles. In order to improve the mechanical response of the PLA/potato pulp powder biocomposites, surface treatment of the potato pulp particles with bio-based and petroleum-based waxes was investigated. This treatment was found to improve the properties of the biocomposites, enhancing the adhesion between the PLA based polymeric matrix and the potato pulp fibers. The best result is obtained with a petroleum-based wax, but also the bio-based waxes lead to good mechanical properties of the biocomposite. Thus, the addition to PLA of potato pulp powder, treated with waxes, appears a method able to (i) utilize and valorize an abundant agro-food biomass such as potato pulp, according to the principles of circular economy, (ii) favor the production of articles with properties valuable for practical applications, and (iii) reduce the cost of the final products, considering the relatively high cost of PLA.

Raman Microspectroscopy as a Tool to Elucidate the Efficacy of Topical Formulations Containing Curcumin

The success of the onychomycosis treatment is directly associated with factors such as the choice of the medication, the administration route, and the pharmaceutical formulation. Photodynamic therapy (PDT) is an emerging and promising technique indicated for onychomycosis treatment. For this application, the main challenge is the efficient delivery of the photosensitizer (PS). Curcumin is widely used as a PS, however it is an unstable molecule and it is a challenge to develop a formulation with good penetration into the nail plate, maintaining the stability of curcumin. In this study, the molecular mechanisms underlying the efficacy of two topical formulations containing curcumin used in a clinical trial for onychomycosis treatment were analyzed by Raman microspectroscopy. It is shown that curcumin is present in both formulations in aggregated and non-aggregated states, and in aggregates it is present in different conformations, depending on the interaction with the solvent. This proves to be critical for efficient and uniform PS delivery to the nail and its complete use during the treatment. These analyses are showing how promising Raman microspectroscopy is in understanding the molecular mechanisms of the efficiency of photosensitizers and are helping to improve the development of pharmaceutical formulations.

Thermal and Mechanical Properties of Biocomposites Made of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Potato Pulp Powder

The thermal and mechanical properties of biocomposites of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) containing 5 wt % of valerate units, with 20 wt % of potato pulp powder were investigated in order (i) to obtain information on possible miscibility/compatibility between the biopolymers and the potato pulp, and (ii) to quantify how the addition of this filler modifies the properties of the polymeric material. The potato pulp powder utilized is a residue of processing for the production and extraction of starch. The final aim of this study is the preparation of PHBV based materials with reduced cost, thanks to biomass valorization, in agreement with the circular economy policy, as result of the incorporation of agricultural organic waste. The results showed that the potato pulp powder does not act as reinforcement, but rather as filler for the PHBV polymeric matrix. A moderate loss in mechanical properties is detected (decrease in elastic modulus, tensile strength and elongation at break), which regardless still meets the technical requirements indicated for rigid packaging production. In order to improve the mechanical response of the PHBV/potato pulp powder biocomposites, surface treatment of the potato pulp powder with bio-based and petroleum-based waxes was investigated. Good enhancement of the mechanical properties was achieved with the natural carnauba and bee waxes.

Edible oleogels: an opportunity for fat replacement in foods

The scientific and industrial communities have been giving great attention to the development of new bio-based materials with potential use in innovative technological applications. Among these materials are the structures with gel-like behavior that can be used in the cosmetic, pharmaceutical and food industries, aiming at controlling the physical properties of the final products. In the past ten years, words like oleogels and organogels have been increasingly used, the existing number of manuscripts and patents being proof of this tendency. In the food industry, oleogels can be used to control phase separation, and decrease the mobility and migration of the oil phase, providing solid-like properties without using high levels of saturated fatty acids as well as to be a carrier of bioactive compounds. In most cases, their main features are related to the reorganization process of gelators after an increase of the temperature, above the melting or glass transition temperature of the materials, known as the direct method, but it is also possible to develop oleogels by indirect methods, such as emulsification and the solvent exchange technique. In the direct methods, the reorganization is able to physically entrap oil leading to different physicochemical properties, the rheological behavior and texture properties being the frequently most studied ones. This review overviews the use of food grade and bio-based structurants to produce edible oleogels, aiming at fat replacement and structure-tailoring. Gelation mechanisms and oil phases used during oleogel production are discussed, as well as the current food applications and future trends for this kind of structure.

Antioxidant, antihyperglycemic, and antidiabetic activity of Apis mellifera bee tea

Diabetes has emerged as one of the largest global epidemics; it is estimated that by 2035, there will be 592 million diabetic people in the world. Brazilian biodiversity and the knowledge of traditional peoples have contributed to the treatment of several diseases, including diabetes. Apis mellifera bee tea is used by indigenous Brazilians to treat diabetes, and this traditional knowledge needs to be recorded and studied.The objective of this study was to record the use and to evaluate the antioxidant, antihyperglycemic, and antidiabetic activity of Apis mellifera bee tea, which is used by the Guarani and Kaiowá indigenous people for the treatment of diabetes. Semi-structured interviews were performed with Guarani and Kaiowá ethnic indigenous people from the State of Mato Grosso do Sul, Brazil, seeking to identify the animal species used for medicinal purposes. For the experimental procedures, tea prepared with macerated Apis mellifera bees was used. In vitro assays were performed to evaluate antioxidant activity; direct free radical scavenging, protection against oxidative hemolysis, lipid peroxidation were evaluated in human erythrocytes and potential in inhibiting the formation of advanced glycation end products (AGEs). In vivo, normoglycemic Swiss male mice treated with Apis mellifera tea (AmT) were subjected to the oral glucose tolerance test and compared with control and metformin-treated groups. Diet-induced diabetic mice were treated for 21 days with AmT and evaluated for glycemia and malondialdehyde levels in the blood, liver, nervous system, and eyes. During interviews, the indigenous people described the use of Apis mellifera bee tea for the treatment of diabetes. In in vitro assays, AmT showed direct antioxidant activity and reduced oxidative hemolysis and malondialdehyde generation in human erythrocytes. The AmT inhibited the formation of AGEs by albumin-fructose pathways and methylglyoxal products. In vivo, after oral glucose overload, normoglycemic mice treated with AmT had reduced hyperglycemia at all times evaluated up to 180 min. AmT also reduced hyperglycemia and malondialdehyde levels in the blood, liver, nervous system, and eyes of diabetic mice to similar levels as those in metformin-treated mice and normoglycemic controls. In summary, Apis mellifera bee tea showed antioxidant, antihyperglycemic, and antidiabetic activity, which provides support for the therapeutic application of Guarani and Kaiowá indigenous knowledge.

Beeswax: A minireview of its antimicrobial activity and its application in medicine

Beeswax is the substance that forms the structure of a honeycomb; the bees secrete wax to build the honeycombs where to store honey. Thanks to its rich hydrophobic protective properties, the beeswax is in fact present within cosmetics and body products. Also, beeswax is used in the food industry: as a film to wrap cheese for maturing or as a food additive (E901) to give shine to the products. Exactly as the honey which it contains, beeswax is also characterized by several therapeutic properties of great interest to us; it is thought to be particularly effective in healing bruises, inflammation and burns. Recently, the interest of researchers has moved even on antimicrobial properties of beeswax although there are still few studies in the literature focused only on the action of beeswax. The few studies showed an antimicrobic effectiveness of beeswax against overall Staphylococcus aureus, Salmonella enterica, Candida albicans and Aspergillus niger; these inhibitory effects are enhanced synergistically with other natural products such as honey or olive oil. This minireview aims to be a collection of major scientific works that have considered the antimicrobial activity of beeswax alone or in combination with other natural products in recent years.

Characteristics and chemical compositions of propolis from Ethiopia

Introduction

Propolis is a sticky material mixed by honeybees to utilize it in protecting their hives from infection by bacteria and fungi. The therapeutic properties of propolis are due to its chemical composition with bio-active compounds; therefore, researchers are interested in studying its chemical constituents and biological properties. The main objective of this study is to determine the chemical compositions, characteristics and relative concentrations of organic compounds in the extractable organic matter of propolis samples collected from four different areas in Ethiopia.

Results

The propolis samples were extracted with a mixture of dichloromethane and methanol and analyzed by gas chromatography–mass spectrometry (GC-MS).The results showed that the total extract yields ranged from 27.2% to 64.2% (46.7 ± 19.1%). The major compounds were triterpenoids (85.5 ± 15.0% of the total extracts, mainly α-, β-amyrins and amyryl acetates), n-alkanes (5.8 ± 7.5%), n-alkenes (6.2 ± 7.0%,), methyl n-alkanoates (0.4 ± 0.2%), and long chain wax esters (0.3 to 2.1%).

Conclusion

The chemical compositions of these propolis samples indicate that they are potential sources of natural bio-active compounds for biological and pharmacological applications.

Photoprotection for deltamethrin using chitosan-coated beeswax solid lipid nanoparticles

BACKGROUND

In the natural environment, photodegradation is one of the most common degradative processes of pesticides. In order to reduce the photodegradation of pesticides, and so increase their killing activity against target pests, chitosan-coated beeswax solid lipid nanoparticles (CH-BSLNs) were prepared by a combination of hot homogenization and sonication, with deltamethrin as an active ingredient.

RESULTS

Under optimal conditions, the highest encapsulation efficiency (95%) and a high payload of deltamethrin (approximately 12.5%) were achieved. In direct photolysis, in the case of CH-BSLNs after UV irradiation for 24 h, 37.3% of deltamethrin remained, as opposed to only 14.6% of the free-form deltamethrin. In addition, in indirect photolysis, in the case of CH-BSLNs after UV irradiation for 2 h in 2% acetone solution, approximately 74.5% of deltamethrin remained, as opposed to only 37.6% of the free-form deltamethrin.

CONCLUSION

CH-BSLNs showed good protection for deltamethrin against photodegradation. This novel nanocarrier may be useful in crop protection as an economical strategy to enhance the effect of pesticides in the field and protect the environment as well.

The thermal properties of beeswaxes: unexpected findings

Standard melting point analyses only partially describe the thermal properties of eusocial beeswaxes. Differential scanning calorimetry (DSC)revealed that thermal phase changes in wax are initiated at substantially lower temperatures than visually observed melting points. Instead of a sharp,single endothermic peak at the published melting point of 64°C, DSC analysis of Apis mellifera Linnaeus wax yielded a broad melting curve that showed the initiation of melting at approximately 40°C. Although Apis beeswax retained a solid appearance at these temperatures, heat absorption and initiation of melting could affect the structural characteristics of the wax. Additionally, a more complete characterization of the thermal properties indicated that the onset of melting, melting range and heat of fusion of beeswaxes varied significantly among tribes of social bees(Bombini, Meliponini, Apini). Compared with other waxes examined, the relatively malleable wax of bumblebees (Bombini) had the lowest onset of melting and lowest heat of fusion but an intermediate melting temperature range. Stingless bee (Meliponini) wax was intermediate between bumblebee and honeybee wax (Apini) in heat of fusion, but had the highest onset of melting and the narrowest melting temperature range. The broad melting temperature range and high heat of fusion in the Apini may be associated with the use of wax comb as a free-hanging structural material, while the Bombini and Meliponini support their wax structures with exogenous materials.

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

New and simpler methods of sample preparation to determine several families of compounds in beeswax by conventional and high temperature gas chromatography are proposed. To analyze hydrocarbons and palmitates, a dilution of sample is enough whereas for the total acid content, a hydrolysis and simultaneous methylation with BF3-methanol results more effective than the usual methods; for the total content of alcohols, a further acetylation with acetic anhydride is necessary. Free alcohols are directly acetylated in a sample dissolution but for free acids and monoesterified 1,2,3-propanetriols analysis, a previous extraction with acetonitrile is required. The concentrations of all the compounds studied are expressed in weight percentage referred only to one standard: octadecyl octadecanoate. The precision of the analytical methods has been evaluated showing its importance in the analysis of beeswaxes used in apiculture.

Quality assurance of commercial beeswax II. Gas chromatography-electron impact ionization mass spectrometry of alcohols and acids

Gas chromatography with mass spectrometric detection was used to find the fraction of alcohols and acids present in pure beeswax from Apis mellifera. Some new compounds not described till now were found, such as a family of unsaturated linear fatty acids, several hydroxyacids and 1,2,3-propanetriol monoesters. The chromatographic profiles obtained from pure beeswax and bee-rejected foundation beeswax can be used to discriminate them; they mainly differ in the amount of some acids and alcohols.